41 results on '"Jong-Ha Choi"'
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2. Synthesis, Vibrational Spectroscopy, Crystal Structure and Hirshfeld Surface Analysis of Sodium Aquadichlororido[N-(3-aminopropyl)-N′-(propyl)ethane-1,2-diamine]chromium(III) Tetrachloridozincate
- Author
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Jong-Ha Choi and Dohyun Moon
- Subjects
Chromium ,chemistry.chemical_compound ,chemistry ,Sodium ,Diamine ,chemistry.chemical_element ,Physical chemistry ,Infrared spectroscopy ,General Chemistry ,Crystal structure - Published
- 2018
3. Crystal structure and anti/syn-conformational isomers of trans-bis[dibromobis(2,2-dimethyl-1,3-propanediamine)chromium(III)] tetrabromozincate
- Author
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Jong-Ha Choi and Dohyun Moon
- Subjects
010405 organic chemistry ,Tetrahedral molecular geometry ,chemistry.chemical_element ,Crystal structure ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Ion ,Inorganic Chemistry ,Bond length ,Chromium ,Crystallography ,chemistry ,Octahedral molecular geometry ,Materials Chemistry ,Orthorhombic crystal system ,Physical and Theoretical Chemistry ,Conformational isomerism - Abstract
A new complex, trans-anti/syn-[CrBr2(Me2tn)2]2ZnBr4 (1) (Me2tn = 2,2-dimethyl-1,3-propanediamine, C5H14N2), was prepared, and its structure was characterized by single-crystal X-ray diffraction and infrared (IR) spectroscopy. The complex crystallizes in the orthorhombic space group, Pnma, with eight formula units in a cell with dimensions of a = 16.415(3), b = 41.130(8), and c = 12.372(3) A. X-ray structural analysis reveals three crystallographically independent Cr(III) complex cations in the complex. In the complex cations, Cr(III) ions are coordinated by four N atoms belonging to the two chelating Me2tn and two bromides, in a trans arrangement, displaying a distorted octahedral geometry. Interestingly, the asymmetric unit contains one-half of a centrosymmetric trans-anti-[Cr1Br2(Me2tn)2]+ (2) cation, one independent trans-syn-[Cr2Br2(Me2tn)2]+ (3) cation, another half of a trans-syn-[Cr3Br2(Me2tn)2]+ (4) cation, and one ZnBr42− anion. The [Cr1Br2(Me2tn)2]+ (2) cation adopts anti chair–chair conformation, whereas the [Cr2Br2(Me2tn)2]+ (3) and [Cr3Br2(Me2tn)2]+ (4) cations adopt syn chair–chair conformations. The Cr–N(Me2tn) bond lengths vary from 2.077(4) to 2.102(5) A, and the Cr–Br bond lengths range from 2.4177(14) to 2.4933(10) A. ZnBr42− anion possesses a slightly distorted tetrahedral geometry in which the Zn–Br bond lengths and Br–Zn–Br angles are influenced by hydrogen-bonding interactions. The crystal lattice is stabilized by the hydrogen-bonding interactions between the bromides and NH groups of the Me2tn ligands.
- Published
- 2021
4. Crystal structure of bis[trans-dichloridobis(propane-1,3-diamine-κ2N,N′)chromium(III)] dichromate from synchrotron data
- Author
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Keon Sang Ryoo, Dohyun Moon, and Jong-Ha Choi
- Subjects
crystal structure ,Coordination sphere ,Stereochemistry ,chemistry.chemical_element ,Crystal structure ,Staggered conformation ,010402 general chemistry ,010403 inorganic & nuclear chemistry ,01 natural sciences ,Ion ,Research Communications ,chromium(III) complex ,lcsh:Chemistry ,Chromium ,General Materials Science ,dichromate anion ,chloride ligand ,Chemistry ,Hydrogen bond ,synchrotron radiation ,General Chemistry ,Condensed Matter Physics ,hydrogen bonding ,propane-1,3-diamine ,0104 chemical sciences ,propane-1,3-diamine ,Bond length ,Crystallography ,lcsh:QD1-999 ,trans–anti conformation ,Amine gas treating - Abstract
In the title organic–inorganic salt, [CrCl2(tn)2]2[Cr2O7] (tn is propane-1,3-diamine), the CrIII ions are coordinated by four N atoms from two tn ligands and two chloride ions in a trans geometry, displaying a distorted octahedral arrangement. The crystal packing is stabilized by N—H⋯Cl and N—H⋯O hydrogen bonds., The structure of the title compound, [CrCl2(tn)2]2[Cr2O7] (tn = propane-1,3-diamine; C3H10N2), has been determined from synchrotron data. The asymmetric unit contains one CrIII complex cation and half a [Cr2O7]2− anion. In the complex cation, the CrIII ion is coordinated by the four N atoms of two propane-1,3-diamine (tn) ligands in the equatorial plane and by two Cl atoms in a trans configuration, displaying a distorted octahedral coordination sphere. The two six-membered rings in the complex cation have an anti chair–chair conformation with respect to each other. The mean Cr—N(tn) and Cr—Cl bond lengths are 2.09 (1) and 2.320 (2) Å, respectively. The slightly bent dichromate anion is disordered over two sets of sites (occupancy ratio = 0.7:0.3) and has a staggered conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the NH2 groups of the tn ligands as donors and the O atoms of the [Cr2O7]2− anion and chlorido ligands as acceptors.
- Published
- 2016
5. Crystal structure of cis-(1,4,8,11-tetraazacyclo-tetradecane-κ4N)bis(thiocyanato- κN)chromium(III) bromide from synchrotron X-ray diffraction data.
- Author
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Dohyun Moon and Jong-Ha Choi
- Subjects
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CRYSTAL structure , *X-ray diffraction , *CHROMIUM , *BROMIDES , *CHEMICAL bond lengths , *SYNCHROTRONS , *MACROCYCLIC compounds - Abstract
The crystal structure of the title complex, cis-[Cr(NCS)2(cyclam)]Br (cyclam = 1,4,8,11-tetraazacyclotetradecane, C10H24N4), has been determined from synchrotron X-ray data. The asymmetric unit contains one [Cr(NCS)2(cyclam)]+ cation and one bromide anion. The CrIII ion of the complex cation is coordinated by the four N atoms of the cyclam ligand and by two N-coordinating NCS groups in a cis arrangement, displaying a distorted octahedral coordination sphere. The Cr--N(cyclam) bond lengths are in the range 2.075 (3) to 2.081 (3) Å while the average Cr--N(NCS) bond length is 1.996 (16) Å. The macrocyclic cyclam moiety adopts the most stable cis-V conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the cyclam N--H groups as donor groups, and the bromide anion and the S atom of one of the NCS ligands as acceptor groups. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
6. Synthesis, crystal structure and spectroscopic properties oftrans-dibromidobis(2,2-dimethylpropane-1,3-diamine-κ2N,N′)chromium(III) perchlorate
- Author
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Dohyun Moon and Jong-Ha Choi
- Subjects
Chromium ,Ligand field theory ,Perchlorates ,Spectroscopy, Near-Infrared ,Hydrogen bond ,Ligand ,Inorganic chemistry ,chemistry.chemical_element ,Crystal structure ,Crystallography, X-Ray ,Ligands ,Condensed Matter Physics ,Inorganic Chemistry ,Perchlorate ,chemistry.chemical_compound ,Crystallography ,X-Ray Diffraction ,chemistry ,Coordination Complexes ,Diamine ,Octahedral molecular geometry ,Materials Chemistry ,Physical and Theoretical Chemistry - Abstract
The title complex salt,trans-anti-[CrBr2(Me2tn)2]ClO4(where Me2tn = 2,2-dimethylpropane-1,3-diamine, C5H14N2), was prepared and its structure determined by single-crystal X-ray diffraction at 100 K. The asymmetric unit contains three conformationally similar complex cations and three perchlorate anions. In each complex cation, the CrIIIcentre is coordinated by four N atoms of two chelating Me2tn ligands in the equatorial plane and by two Br atoms in atrans-axial arrangement, to give a distorted octahedral geometry. Interionic contacts are dominated by extensive hydrogen bonding, involving the NH groups of the Me2tn ligand as donors and the anion O atoms or coordinated Br atoms as acceptors, resulting in two-dimensional layers in thebcplane. Ligand field analysis based on the angular overlap model, and IR and electronic spectroscopic properties, are also discussed.
- Published
- 2015
7. Synthesis, crystal structure and spectroscopic properties of trans-difluoro(1,4,7,11-tetraazaundecane)chromium(III) perchlorate
- Author
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Dohyun Moon and Jong-Ha Choi
- Subjects
Ligand field theory ,Absorption spectroscopy ,Hydrogen bond ,Organic Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Crystal structure ,Triclinic crystal system ,Analytical Chemistry ,Inorganic Chemistry ,Bond length ,Crystallography ,Chromium ,Perchlorate ,chemistry.chemical_compound ,chemistry ,Spectroscopy - Abstract
The structure of trans-[Cr(2,2,3-tet)F2]ClO4 (2,2,3-tet = 1,4,7,11-tetraazaundecane) has been determined by single-crystal X-ray diffraction. The complex crystallizes in the space group P 1 ‾ of the triclinic system with two mononuclear formula units in a cell of dimensions a = 5.6741(11), b = 9.971(2), c = 13.222(3) A, α = 73.76(3)o, β = 81.08(3)° and γ = 85.12(3)°. The chromium(III) atom is in a slightly distorted octahedral environment coordinated by four N atoms of 2,2,3-tet and two F ligands in a mutually trans (meso RS) geometry. The mean Cr-N(2,2,3-tet) and Cr F bond lengths are 2.064(9) and 1.885(7) A, respectively. The crystal packing is stabilized by several hydrogen bonds. The 5 K sharp-line absorption spectrum and the 298 K FT-infrared and UV–visible spectra have been measured. Using the electronic transitions, a ligand field optimization has been performed to determine the metal-ligand bonding properties of the coordinated atoms. It is found that the fluoride is a strong σ- and π-donor and the nitrogen atoms of the 2,2,3-tet ligand also have strong σ-donor properties toward the chromium(III).
- Published
- 2014
8. Crystal structure of trans-dichlorido(1,4,8,11-tetraazacyclotetradecane- κ4N)chromium(III) bis(formamide- κO)(1,4,8,11-tetraazacyclotetradecaneκ 4N)chromium(III) bis[tetrachloridozincate(II)].
- Author
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Moon, Dohyun and Jong-Ha Choi
- Subjects
- *
CRYSTAL structure , *FORMAMIDE , *CHROMIUM , *CHEMICAL bond lengths , *INVERSIONS (Geometry) , *HYDROGEN bonding , *SYNCHROTRON radiation , *CATIONS - Abstract
The structure of the title compound, [CrCl2(C10H24N4)][Cr(HCONH2)2- (C10H24N4)][ZnCl4]2 (C10H24N4 = 1,4,8,11-tetraazacyclotetradecane, cyclam; HCONH2 = formamide, fa), has been determined from synchrotron X-ray data. The asymmetric unit contains two independent halves of the [CrCl2(cyclam)]+ and [Cr(fa)(cyclam)]3+ cations, and one tetrachloridozincate anion. In each complex cation, the CrIII ion is coordinated by the four N atoms of the cyclam ligand in the equatorial plane and two Cl ligands or two O-bonded formamide molecules in a trans axial arrangement, displaying a distorted octahedral geometry with crystallographic inversion symmetry. The Cr-- N(cyclam) bond lengths are in the range 2.061 (2) to 2.074 (2) A ° , while the Cr--Cl and Cr--O(fa) bond distances are 2.3194 (7) and 1.9953 (19) A ° , respectively. The macrocyclic cyclam moieties adopt the centrosymmetric trans-III conformation with six- and five-membered chelate rings in chair and gauche conformations. The crystal structure is stabilized by intermolecular hydrogen bonds involving the NH or CH groups of cyclam and the NH2 group of coordinated formamide as donors, and Cl atoms of the ZnCl4 2- anion as acceptors. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
9. Crystal structure of cis-aquachloridobis(1,10-phenanthroline-κ2N,N′)chromium(III) tetrachloridozincate monohydrate from synchrotron data
- Author
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Jong-Ha Choi and Dohyun Moon
- Subjects
crystal structure ,1,10-phenanthroline ,Phenanthroline ,chemistry.chemical_element ,Crystal structure ,Research Communications ,Ion ,chromium(III) complex ,lcsh:Chemistry ,chemistry.chemical_compound ,Chromium ,General Materials Science ,cis-geometry ,chloride ligand ,biology ,Chemistry ,Hydrogen bond ,synchrotron radiation ,aqua ligand ,General Chemistry ,Condensed Matter Physics ,biology.organism_classification ,Bond length ,Crystallography ,lcsh:QD1-999 ,Tetra ,Zincate - Abstract
The CrIII ion in the title complex is coordinated by two 1,10-phenanthroline (phen) ligands, one water molecule and a chloride in a cis geometry, displaying a distorted octahedral environment. The [ZnCl4]2− anion has a slightly distorted tetrahedral coordination geometry., The structure of the title compound, [CrCl(C12H8N2)2(H2O)][ZnCl4]·H2O, has been determined from synchrotron data. The CrIII ion is bonded to four N atoms from two 1,10-phenanthroline (phen) ligands, one water molecule and a Cl atom in a cis arrangement, displaying an overall distorted octahedral coordination environment. The Cr—N(phen) bond lengths are in the range of 2.0495 (18) to 2.0831 (18) Å, while the Cr—Cl and Cr—(OH2) bond lengths are 2.2734 (7) and 1.9986 (17) Å, respectively. The tetrahedral [ZnCl4]2− anion is slightly distorted owing to its involvement in O—H⋯Cl hydrogen bonding with coordinating and non-coordinating water molecules. The two types of water molecules also interact through O—H⋯O hydrogen bonds. The observed hydrogen-bonding pattern leads to the formation of a three-dimensional network structure.
- Published
- 2015
10. Crystal structure of trans-di-chlorido-(1,4,8,11-tetra-aza-undecane-κ(4) N)chromium(III) perchlorate determined from synchrotron data
- Author
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Jong-Ha Choi and Dohyun Moon
- Subjects
crystal structure ,1,4,8,11-tetraazaundecane ,chemistry.chemical_element ,Crystal structure ,010402 general chemistry ,01 natural sciences ,Chloride ,Research Communications ,1,4,8,11-tetraazaundecane ,chromium(III) complex ,lcsh:Chemistry ,chemistry.chemical_compound ,Perchlorate ,Chromium ,medicine ,General Materials Science ,trans–meso (RS) conformation ,chloride ligand ,010405 organic chemistry ,Ligand ,Hydrogen bond ,synchrotron radiation ,General Chemistry ,Condensed Matter Physics ,hydrogen bonding ,0104 chemical sciences ,Bond length ,Crystallography ,lcsh:QD1-999 ,chemistry ,Undecane ,medicine.drug - Abstract
In the title compound, [CrCl2(C7H20N4)]ClO4, the CrIII ion is coordinated by four N atoms from the 1,4,8,11-tetraazaundecane ligand and two chloride ions in a trans geometry, displaying a distorted octahedral arrangement. The crystal packing is stabilized by N—HCl and N—H⋯O hydrogen bonds., The structure of the title complex, [CrCl2(2,3,2-tet)]ClO4 (2,3,2-tet is 1,4,8,11-tetraazaundecane, C7H20N4), has been determined from synchrotron data. The CrIII ion is coordinated by the four N atoms of the 1,4,8,11-tetraazaundecane ligand in the equatorial plane and two chloride ions in an axial arrangement, displaying a slightly distorted octahedral coordination environment. The two H atoms of the secondary amines are grouped on the same side of the equatorial N4 plane (meso-RS conformation). The Cr—N bond lengths range from 2.069 (2) to 2.084 (2) Å, while the mean Cr—Cl bond length is 2.325 (2) Å. The crystal structure is stabilized by intermolecular hydrogen-bonding interactions between the primary and secondary amine groups of the 2,3,2-tet ligands, the Cl ligands and the O atoms of the perchlorate counter-anion, forming corrugated layers parallel to (010).
- Published
- 2016
11. Crystal Structure and Spectroscopic Properties of trans-Dibromidobis(propane-1, 3-diamine)chromium(III) Perchlorate
- Author
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Seik Weng Ng, Abdus Subhan, and Jong-Ha Choi
- Subjects
Hydrogen bond ,Inorganic chemistry ,chemistry.chemical_element ,Infrared spectroscopy ,Crystal structure ,Triclinic crystal system ,Inorganic Chemistry ,Crystal ,Perchlorate ,chemistry.chemical_compound ,Chromium ,Crystallography ,chemistry ,Diamine - Abstract
The structure of trans-[Cr(tn)2Br2]ClO4 (tn = propane-1, 3-diamine) has been determined by a single-crystal X-ray diffraction study at 100 K. The complex crystallizes in the space group P of the triclinic system with two mononuclear formula units in a cell of dimensions a = 6.8220(4), b = 8.86199(9), c = 12.6644(8) A and α = 77.859(7)°, β = 81.765(6)°, and γ = 77.764(7)°. The chromium atom is in a slightly distorted octahedral environment coordinated by four nitrogen atoms of two tn ligands and two bromine atoms in trans positions. The two six-membered chelate rings in the complex cations are oriented in an anti chair-chair conformation with respect to each other. The mean Cr–N(tn) and Cr–Br bonds are 2.093(3) and 2.4681(4) A, respectively. The crystal packing is stabilized by hydrogen bonds. The infrared and electronic absorption spectral properties are consistent with the result of X-ray crystallography. It is confirmed that the nitrogen atoms of the tn ligand are strong σ-donors, but the bromido ligands have weak σ- and π-donor properties toward the chromium(III) ion.
- Published
- 2011
12. Synthesis, Crystal Structure and Spectroscopic Properties of (Acetylacetonato)(1,4,8,11-tetraazacyclotetradecane)chromium(III) Diperchlorate
- Author
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Seik Weng Ng, Jong-Ha Choi, and Abdus Subhan
- Subjects
Ligand ,Stereochemistry ,chemistry.chemical_element ,Crystal structure ,Inorganic Chemistry ,chemistry.chemical_compound ,Chromium ,Crystallography ,chemistry ,Octahedron ,Cyclam ,Molecule ,Chelation ,Macrocyclic ligand - Abstract
The complex [Cr(cyclam)(acac)](ClO(4))(2)center dot 0.5H2O (cyclam = 1,4,8,11-tetraazacyclotetradecane; acac = acetylacetonate) was prepared and structurally characterized by single-crystal X-ray diffraction at 100 K. The chromium atom is in a slightly distorted octahedral environment with four nitrogen atoms of the macrocyclic ligand and two O-bonded acac molecules in cis position. The cyclam ligand adopts the folded cis-V configuration with six- and five-membered chelate rings in chair and gauche conformation, respectively. The average CrN(cyclam) and CrO(acac) bonds are 2.080(4) and 1.941(3) angstrom, respectively. The IR and visible spectral properties are also described.
- Published
- 2011
13. Crystal Structure and Spectroscopic Properties of Bis[trans-dichlorobis(2,2-dimethylpropane-1,3-diamine)chromium(III)] Tetrachlorozincate
- Author
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Leone Spiccia, Jong-Ha Choi, and Tanmaya Joshi
- Subjects
Inorganic Chemistry ,Bond length ,Crystallography ,chemistry.chemical_compound ,Chromium ,chemistry ,Hydrogen bond ,Diamine ,X-ray crystallography ,Octahedral molecular geometry ,Infrared spectroscopy ,chemistry.chemical_element ,Crystal structure - Abstract
The structure of trans-[Cr(Me2tn)2Cl2]2ZnCl4 (Me2tn = 2,2-dimethylpropane-1,3-diamine) was determined by a single-crystal X-ray diffraction study at 173 K. The analysis reveals that there are three crystallographically independent chromium(III) complex cations in the title compound. The chromium(III) atoms are coordinated by four nitrogen atoms of Me2tn and two chlorine atoms in a trans arrangement, displaying a distorted octahedral geometry. The two six-membered chelate rings in three complex cations are oriented in an anti chair–chair conformation with respect to each other. The Cr–N and Cr–Cl bond lengths average 2.0862(2) and 2.3112(6) A, respectively. The ZnCl42– have slightly distorted tetrahedral arrangement with Zn–Cl lengths and the Cl–Zn–Cl angles are influenced by hydrogen bonding. The resolved absorption maxima in the electronic d–d spectrum were fitted with a secular determinant for a quartet energy state of the d3 configuration in a tetragonal field. It is confirmed that the nitrogen atoms of the Me2tn ligand are strong σ donors, but the chloro ligands have weak σ- and π donor properties toward the chromium(III) ion.
- Published
- 2011
14. Crystal Structure and Spectroscopic Properties of cis-β-Diazido(1,4,7,11-tetraazaundecane)chromium(III) Bromide
- Author
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Jong-Ha Choi, Ross W. Harrington, and William Clegg
- Subjects
Hydrogen bond ,Inorganic chemistry ,Ionic bonding ,chemistry.chemical_element ,Crystal structure ,Inorganic Chemistry ,Bond length ,Chromium(III) bromide ,chemistry.chemical_compound ,Chromium ,Crystallography ,chemistry ,Octahedron ,Azide - Abstract
The new complex, cis-β-[Cr(2,2,3-tet)(N3)2]Br (2,2,3-tet = 1,4,7,11-tetraazaundecane), was prepared and its structure was determined by single-crystal X-ray diffraction. The chromium(III) atom is in a distorted octahedral environment coordinated by four nitrogen atoms of 2,2,3-tet and two azido ligands in a cis-β arrangement, with bent Cr–N3 linkages at the coordinating azide nitrogen atoms. The mean Cr–N(2,2,3-tet) and Cr–N(azide) bond lengths are 2.084(5) and 2.021(5) A, respectively. The crystal structure is stabilized by ionic interactions, supported by N–H···N(azide) and N–H···Br hydrogen bonds. The IR and electronic spectroscopic properties are also discussed.
- Published
- 2010
15. Crystal structure and spectroscopic properties of trans-diisothiocyanatobis(2,2-dimethyl-1,3-diaminopropane)chromium(III) thiocyanate
- Author
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Jong-Ha Choi and Sang Hak Lee
- Subjects
Ligand field theory ,Thiocyanate ,Hydrogen bond ,Organic Chemistry ,chemistry.chemical_element ,1,3-Diaminopropane ,Crystal structure ,Triclinic crystal system ,Analytical Chemistry ,Inorganic Chemistry ,Chromium ,chemistry.chemical_compound ,Crystallography ,chemistry ,Octahedron ,Spectroscopy - Abstract
The novel complex trans -[Cr(Me 2 tn) 2 (NCS) 2 ]NCS·1/2H 2 O, where Me 2 tn represents 2,2-dimethylpropane-1,3-diamine, was prepared and its structure was determined by single-crystal X-ray diffraction at 150 K. The complex crystallizes in the space group P 1 ¯ of the triclinic system with two mononuclear formula units in a cell of dimensions a = 8.8359(6), b = 10.4926(7), c = 12.5136(9) A and α = 66.124(2)° , β = 88.795(2)° and γ = 89.530(2)°. The chromium atom is in a slightly distorted octahedral environment coordinated by four N atoms of two chelating Me 2 tn and two N-bonded thiocyanate ligands in trans axial positions. The two six-membered rings in the complex cation have only anti chair–chair conformations with respect to each other. The mean Cr–N(Me 2 tn) and Cr–N(CS) bonds are 2.0807(15) and 1.9826(15) A, respectively. The crystal structure is stabilized by N–H…S and N–H…N hydrogen bonds. The ligand field analysis as well as the IR and electronic spectral properties are discussed.
- Published
- 2009
16. Crystal Structure and Spectroscopic Properties of cisβ-[CrCl_2(1,4,8,11-tetrazaundecane)chromium(III) Perchlorate
- Author
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Hag-Sung Kim, Mohammad Hossein Habibi, and Jong-Ha Choi
- Subjects
Perchlorate ,chemistry.chemical_compound ,Crystallography ,Chromium ,Chemistry ,Ligand ,Inorganic chemistry ,Structural isomer ,chemistry.chemical_element ,General Chemistry ,Crystal structure - Abstract
The2,3,2-tet ligand is a structural isomer of 1,4,7,11-tetra-azaundecane (2,2,3-tet). The linear tetradentate with fournitrogen atoms as donors can adopt three different configu-rations in chromium(III) complexes with two chloro ligandsas shown in Figure 1. Generally, the chromium(III) tetra-dentate complexes have been shown to have a diversestereochemistry. It is not possible from the CD spectrum toassign the
- Published
- 2008
17. Structural and spectroscopic properties of trans-difluoro(1,4,8,12-tetraazacyclopentadecane)chromium(III) perchlorate hydrate
- Author
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In-Gyung Oh, Woo Taik Lim, Keon Sang Ryoo, Yu Chul Park, Mohammad Hossein Habibi, and Jong-Ha Choi
- Subjects
Chromium ,Models, Molecular ,Perchlorates ,Ligand ,Molecular Conformation ,Crystal structure ,Triclinic crystal system ,Crystallography, X-Ray ,Ring (chemistry) ,Models, Biological ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Perchlorate ,chemistry.chemical_compound ,Tetragonal crystal system ,Crystallography ,Octahedron ,chemistry ,Chromium Compounds ,Spectroscopy, Fourier Transform Infrared ,Organometallic Compounds ,Hydrate ,Instrumentation ,Spectroscopy - Abstract
The structure of [CrF(2)([15]aneN(4))]ClO(4).H(2)O ([15]aneN(4)=1,4,8,12-tetraazacyclopentadecane) has been determined by a single-crystal X-ray diffraction study at 173 K. The complex crystallizes in the space group P1- of the triclinic system with two mononuclear formula units in a cell of dimensions a=9.6117(7) A, b=10.2882(7) A, c=11.0001(7) A and alpha=99.7570(10) degrees, beta=105.6080(10) degrees and gamma=113.7130(10) degrees. The complex cation unit has its central Cr atom in an octahedral coordination with four nitrogen atoms and two fluorine atoms in a trans position. Three six-membered and one five-membered chelate rings of the [15]aneN(4) ligand are in a chair-twist(skew)-chair-gauche conformation sequence. The gauche five-membered ring is disordered with the twist six-membered ring opposite. The four H atoms in the chiral N atoms have the trans-II (CTCg) type configuration. The mean Cr-N and Cr-F bonds are 2.095(2) and 1.8752(13) A, respectively. The IR and visible spectral properties are consistent with the result of X-ray crystallography. The resolved band maxima of the electronic d-d spectrum are fitted with secular determinant for quartet state energy of d(3) configuration in tetragonal field including configurational but neglecting spin-orbit coupling. It is confirmed that the fluoride has strong sigma- and pi-donor properties toward the chromium(III) ion and the nitrogen atoms of the [15]aneN(4) ligand also have a strong sigma-donor character.
- Published
- 2006
18. Crystal structure of bis[bis(1,4,7-triazacyclononane-κ³N,N′,N′′)chromium(III)] tris(tetrachloridozincate) monohydrate from synchrotron X-ray data.
- Author
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Dohyun Moon and Jong-Ha Choi
- Subjects
- *
CRYSTAL structure , *CHROMIUM , *SYNCHROTRONS , *X-rays , *BOND angles , *CHEMICAL bond lengths - Abstract
The structure of the title compound, [Cr(tacn)2]2[ZnCl4]3·H2O (tacn is 1,4,7-triazacyclononane; C6H15N3), has been determined from synchrotron X-ray data. Each CrIII cation is coordinated by the six N atoms from the two tacn ligands, displaying a distorted octahedral geometry. Three distorted tetrahedral [ZnCl4]2− anions and one lattice water molecule lie outside this coordination sphere. The Cr—N bond lengths are in the range 2.0621 (11) to 2.0851 (12) Å, while the mean inner N—Cr—N bond angle is 82.51 (5)°. The crystal packing is stabilized by hydrogen-bonding interactions with the N—H groups of the tacn ligands and the water O—H groups acting as donors, and the O atoms of the water molecules and Cl atoms of the [ZnCl4]2− anions as acceptors. Overall these contacts lead to the formation of a three-dimensional network. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
19. Spectroscopic Properties and Ligand Field Analysis of trans -Dibromo(2,2-dimethyl-1,3-diaminopropane)chromium(III) Moiety
- Author
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Woo Taik Lim, In-Gyung Oh, Jong-Ha Choi, Keon Sang Ryoo, Yu Chul Park, and Dong Ii Kim
- Subjects
Ligand field theory ,Absorption spectroscopy ,Infrared ,Ligand ,Analytical chemistry ,chemistry.chemical_element ,General Chemistry ,Chromium ,Crystallography ,chemistry.chemical_compound ,chemistry ,Bromide ,Emission spectrum ,Absorption (chemistry) - Abstract
The sharp-line absorption and emission spectra of(H 1 3 O 6 ){trans-[Cr(Me 2 tn) 2 Br 2 ]} 2 Br 2 (Cl0 4 ) (Me 2 tn = 2,2-dimethyl-l,3-diaminopropane) have been measured between 13000 cm - 1 and 16000 cm - 1 at 5 K. The 298 K infrared and visible absorption spectra have also been measured. The nine electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using observed transitions, a ligand field analysis has been performed to probe the ligand field properties of coordinated atoms in the title chromium(III) complex ion. The zero-phonon line in the sharp-line absorption spectrum splits into two components by 286 cm - 1 , and the large ""Eg splitting can be reproduced by the modern ligand field theory. It is confirmed that nitrogen atoms of the Me 2 tn ligand have a strong cr-donor character, but the bromide has weak σ- and π-donor properties toward chromium(III) ion.
- Published
- 2005
20. Electronic spectroscopy and ligand-field analysis of cis-carbonato(rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)chromium(III) chloride
- Author
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Rolf Linder, Jong-Ha Choi, In-Gyung Oh, and Thomas Schönherr
- Subjects
Ligand field theory ,Absorption spectroscopy ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,Electron spectroscopy ,Ion ,Chromium(III) chloride ,chemistry.chemical_compound ,Crystallography ,Chromium ,Microcrystalline ,chemistry ,Physical and Theoretical Chemistry ,Ground state - Abstract
The absorption spectra of microcrystalline salts of cis -[Cr(cyc b )(O 2 CO)] + (cyc b = rac -5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) have been measured between 13,000 and 50,000 cm −1 at temperatures down to 2 K. The vibrational intervals of the electronic ground state were extracted by recording emission and far-IR spectra. The zero-phonon line in the sharp-line absorption spectrum splits into two components by 144 cm −1 . The nine electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using the observed transitions, a ligand-field analysis has been performed to probe the ligand-field properties of carbonato group in the chromium(III) complex. It is found that the carbonato oxygen has moderately strong σ- and π-donor properties toward chromium(III) ion.
- Published
- 2004
21. Electronic Spectroscopy and Ligand Field Analysis of trans-[CrX2([15]aneN4)]+(X=F,CI)
- Author
-
Sang Hak Lee, Yu Chul Park, Jong-Ha Choi, and In-Gyung Oh
- Subjects
Ligand field theory ,Crystallography ,Chromium ,Absorption spectroscopy ,Chemistry (miscellaneous) ,Ligand ,Chemistry ,Stereochemistry ,Chemical Engineering (miscellaneous) ,chemistry.chemical_element ,Electron spectroscopy ,Molecular electronic transition - Abstract
The electronic absorption spectra of trans-[CrX 2 ([15]aneN 4 )]ClO 4 ([15]aneN 4 =1,4,8,12-tetraazacyclo-pentadecane; X=F, Cl) complexes have been interpreted using the ligand field theory. An AOMX program is used to opti-mize the differences between the calculated and the observed positions for the spin-allowed transition bands. The crystalfield theory(CFT) parameter is directly related to the angular overlap model(AOM), normalized spherical harmonichamiltonians(NSH), and semiempirical parameters. The various ligand field parameters are discussed in terms of theirchemical significances. According to the ligand field analysis, we can confirm that the fluoride ligand is a very strongσ- and π-donor while the chloride has weak σ- and π-donor properties toward chromium(III) ion.Keywords:Cr(III) Complex, Electronic Transition, Ligand Field Analysis, [15]aneN 4 `@ 2_ ( ' ab LM E c 3 + d'< :; 89 de fN ? D j ghi lm kn" .
- Published
- 2003
22. Simultaneous observation of low temperature 4f–4f and 3d–3d emission spectra in a series of Cr(III)(ox)Ln(III) assembly
- Author
-
Takayoshi Suzuki, Md. Abdus Subhan, Sumio Kaizaki, H. Nakata, and Jong-Ha Choi
- Subjects
Quenching (fluorescence) ,Photoluminescence ,Acetylacetone ,Inorganic chemistry ,Biophysics ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Oxalate ,chemistry.chemical_compound ,Chromium ,chemistry ,Excited state ,Physical chemistry ,Emission spectrum ,Boron - Abstract
We report here the low temperature emission spectra in the heterometal dinuclear 3d–4f assembled molecular system [(acac) 2 Cr III (μ-ox)Ln III (HBpz 3 ) 2 ] (Cr(ox)Ln:acac − =acetylacetonate, ox 2− =oxalate, HBpz 3 − =hydrotris(pyrazol-1-yl)borate; Ln=La, Nd, Ho, Er , Tm and Yb) in comparison with those of Na[Cr(acac) 2 (ox)] and [(HBpz 3 ) 2 Ln(μ-ox)Ln(HBpz 3 ) 2 ](Ln=Nd and Er). From 10 to 150 K the Cr(ox)Ln complexes show a broad emission band around 800 nm from the 2 E state of Cr(III) moiety. At room temperature no 2 E– 4 A 2 emission was observed in the Cr(ox)Ln except for the La and Lu complexes. On warming from 10 to 300 K rapid quenching of the 2 E– 4 A 2 emission of Cr(III) is suggested to result from the energy transfer from Cr to Ln in the Cr(ox)Ln. The excitation spectra and the life-time were also measured with monitoring the 4f–4f emission peaks of the Cr(ox)Yb complex.
- Published
- 2003
23. Ethylenediammonium bis{bis[N-(2-aminoethyl)glycinato-κ3N,N′,O]chromium(III)} tetrachloride dihydrate at 293 and 100 K
- Author
-
Takayoshi Suzuki, Jong-Ha Choi, Md. Abdus Subhan, Sumio Kaizaki, and Yu Chul Park
- Subjects
Hydrogen bond ,Stereochemistry ,Absolute configuration ,chemistry.chemical_element ,General Medicine ,Crystal structure ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Chromium ,Crystallography ,chemistry ,Moiety ,Molecule ,Carboxylate ,Hydrate - Abstract
The crystal structure of the title compound, (C(2)H(10)N(2))[Cr(C(4)H(9)N(2)O(2))(2)](2)Cl(4) x 2H(2)O, has been determined by single-crystal X-ray diffraction studies at 293 and 100 K. The analyses demonstrated that the crystal consists of ethylenediammonium dications (which lie about inversion centres), bis[N-(2-aminoethyl)glycinato]chromium(III) monocations, Cl(-) anions and hydrate water molecules, in a molecular ratio of 1:2:4:2. The complex cation unit has a slightly distorted octahedrally coordinated Cr atom, with two Cr[bond]O and four Cr[bond]N bonds in the ranges 1.951 (1)-1.953 (1) and 2.054 (1)-2.089 (2) A, respectively, at 293 K. The geometry of the bis[N-(2-aminoethyl)glycinato]chromium(III) moiety was found to be trans,cis,cis with respect to the carboxylate O atom and the primary and secondary amine N atoms. The two analyses, at 293 and 100 K, exhibited no remarkable structural differences, although the colour of the crystals did differ, being red at 293 K and orange at 100 K.
- Published
- 2002
24. Spectroscopic and ligand-field properties of [l-prolylglycinato][di(3-aminopropyl)amine]chromium(III) perchlorate
- Author
-
Yu Chul Park, Yong Pyo Hong, and Jong-Ha Choi
- Subjects
Ligand field theory ,Chemical Phenomena ,Chemistry, Physical ,Inorganic chemistry ,chemistry.chemical_element ,Ligands ,Nitrogen ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Ion ,Chromium ,Perchlorate ,chemistry.chemical_compound ,Crystallography ,chemistry ,Spectrophotometry ,Atomic electron transition ,Chromium Compounds ,Spectroscopy, Fourier Transform Infrared ,Amine gas treating ,Absorption (chemistry) ,Instrumentation ,Spectroscopy - Abstract
The mixed ligand complex [Cr( l -progly)(dpt)]ClO 4 [H 2 progly=prolylglycine, dpt=di(3-aminopropyl)amine] has been prepared, and its geometric structure was discussed on the basis of electronic absorption and IR spectral data. The emission and excitation spectra taken at 77 K were also reported. The 12 electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using the electronic transitions, a ligand-field optimization has been performed to determine the metal–ligand bonding properties for the coordinated atoms. We confirmed that the peptide nitrogen of prolylglycinate has moderate strong σ- and weak π-donor properties toward chromium(III) ion.
- Published
- 2002
25. Synthesis, Spectroscopic and Ligand Field Properties of trans-Difluorobis(2,2-dimethylpropane-1,3-diamine)chromium(III) Perchlorate
- Author
-
Sang Hak Lee, Keon Sang Ryoo, and Jong-Ha Choi
- Subjects
Ligand field theory ,Inorganic chemistry ,chemistry.chemical_element ,General Chemistry ,Ring (chemistry) ,Metal ,Chromium ,Crystallography ,Perchlorate ,chemistry.chemical_compound ,Transition metal ,chemistry ,Diamine ,visual_art ,visual_art.visual_art_medium ,Conformational isomerism - Abstract
The preparation and characterization of novel chromium(III) complexes have received much attention because the chromium(III) materials are promising materials for tunable solid state laser in the spectral region between 600 and 1100 nm. 1 As a prerequisite for these applications, a detailed study of the spectroscopic and ligand field properties is needed. Furthermore, the geometrical and conformational isomerism in transition metal complexes has been an area of intense activity and has provided much basic structural information. 2 The 2,2-dimethylpropane-1,3-diamine (Me2tn) as a bidentate ligand can coordinate to a central metal ion forming a six-membered ring, and the spectroscopic properties of the resulting metal complexes can be compared with those of the corresponding complexes containing the unsubstituted tn diamine system. 3
- Published
- 2011
26. Bis[trans-difluoridotetrakis(pyridine-κN)chromium(III)] sodium tetrachloridozincate perchlorate from synchrotron data
- Author
-
Jong-Ha Choi, Keon Sang Ryoo, and Dohyun Moon
- Subjects
Metal-Organic Papers ,crystal structure ,biology ,Hydrogen bond ,chemistry.chemical_element ,General Chemistry ,Crystal structure ,Condensed Matter Physics ,Bioinformatics ,biology.organism_classification ,Bond length ,lcsh:Chemistry ,chemistry.chemical_compound ,Crystallography ,Perchlorate ,Chromium ,chemistry ,lcsh:QD1-999 ,Pyridine ,Tetra ,General Materials Science ,Zincate - Abstract
The title salt, Na[CrF2(C5H5N)4]2[ZnCl4]ClO4, consists of two cationic CrIIIcomplexes, an Na+cation, one [ZnCl4]2−anion and one ClO4−anion. The CrIIIatoms are coordinated by four pyridine (py) N atoms and two F atoms in atransarrangement, displaying a distorted octahedral geometry. The mean Cr—N(py) and Cr—F bond lengths are 2.086 (8) and 1.864 (14) Å, respectively. The [ZnCl4]2−anion has a distorted tetrahedral geometry. The most notable feature of the crystal packing is the formation of weak pyridine–perchlorate C—H...O hydrogen bonds, resulting in supramolecular chains along theb-axis direction. The perchlorate anion was disordered over two sets of sites in a 0.868 (3):0.132 (3) ratio.
- Published
- 2014
27. Spectral properties and ligand field analysis of cis-dinitrito(1,4,8,11-tetraazacyclotetradecane)chromium(III) nitrate
- Author
-
Jong-Ha Choi
- Subjects
Ligand field theory ,Absorption spectroscopy ,Chemistry ,Infrared ,Ligand ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,Chromium ,Crystallography ,chemistry.chemical_compound ,Cyclam ,Emission spectrum ,Physical and Theoretical Chemistry ,Ground state - Abstract
The 77 K emission and excitation spectra, and 298 K infrared and absorption spectra of cis -[Cr(cyclam)(ONO) 2 ]NO 3 (cyclam=1,4,8,11-tetraazacyclotetradecane) have been measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The 10 electronic bands due to spin-allowed and spin-forbidden transitions are assigned. Using the observed electronic transitions, a ligand field analysis was performed in the framework of the angular overlap model. It is confirmed that nitrogen atoms of the cyclam ligand have a strong σ-donor character, but nitrito ligand has weak σ- and π-donor properties toward chromium(III) ion.
- Published
- 2000
28. cis-(1,4,8,11-Tetra-aza-cyclo-tetra-decane-κN (4))bis(-thio-cyanato-κN)chromium(III) thio-cyanate
- Author
-
Keon Sang Ryoo, Yong Pyo Hong, Dohyun Moon, and Jong-Ha Choi
- Subjects
Metal-Organic Papers ,biology ,Chemistry ,Thio ,chemistry.chemical_element ,General Chemistry ,Crystal structure ,Condensed Matter Physics ,biology.organism_classification ,Cyanate ,Medicinal chemistry ,Bond length ,chemistry.chemical_compound ,Chromium ,Cyclam ,Tetra ,General Materials Science ,Macrocyclic ligand - Abstract
The crystal structure of [Cr(NCS)2(cyclam)]NCS (cyclam = 1,4,8,11-tetra-aza-cyclo-tetra-deca-ne, C10H24N4) has been determined by using synchrotron radiation at 98 K. The Cr(III) atom is in a slightly distorted octa-hedral environment with four N atoms of the macrocyclic ligand and two N-coordinated NCS(-) anions in cis positions. The average Cr-N(cyclam) and Cr-NCS bond lengths are 2.085 (5) and 1.996 (15) Å, respectively. In the crystal, the uncoordinating SCN(-) anion is hydrogen bonded through N-H⋯S and N-H⋯N inter-actions to neighbouring complex cations.
- Published
- 2013
29. cis-Dinitrito(1,4,8,11-tetraazacyclotetradecane-κ4N)chromium(III) nitrite
- Author
-
Woo Taik Lim, In-Gyung Oh, Ki-Min Park, and Jong-Ha Choi
- Subjects
Denticity ,Stereochemistry ,chemistry.chemical_element ,General Medicine ,Crystal structure ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Chromium ,Crystallography ,chemistry ,Octahedron ,Transition metal ,Cyclam ,Nitrite ,Cis–trans isomerism - Abstract
In the title compound, [Cr(ONO)(2)(cyclam)]NO(2) (cyclam is 1,4,8,11-tetraazacyclotetradecane, C(10)H(24)N(2)), the complex cation is located on a twofold symmetry axis. The central Cr atom has a distorted octahedral coordination, involving two Cr-O bonds, with the monodentate nitrite O atoms adopting a cis configuration, and four Cr-N bonds. The mean Cr-N and Cr-O distances are 2.0895 (14) and 1.9698 (14) A.
- Published
- 2004
30. Erratum to 'Crystal structure and spectroscopic properties of trans-diisothiocyanatobis(2,2-dimethyl-1,3-diaminopropane)chromium(III) thiocyanate' [J. Mol. Struct. 932 (2009) 84–89]
- Author
-
Jong-Ha Choi and Sang Hak Lee
- Subjects
Thiocyanate ,Organic Chemistry ,chemistry.chemical_element ,1,3-Diaminopropane ,Crystal structure ,010402 general chemistry ,010403 inorganic & nuclear chemistry ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Inorganic Chemistry ,Chromium ,chemistry.chemical_compound ,Crystallography ,chemistry ,struct ,Spectroscopy - Published
- 2016
31. Crystal structure and conformational analysis of s-cis-(acetylacetonato)(ethylenediamine-N,N'-diacetato)-chromium(III): development of vibrationally optimized force field (VOFF)
- Author
-
Svetozar R. Niketić, Jong-Ha Choi, Ivana Okić Djordjević, William Clegg, and Ross W. Harrington
- Subjects
Chromium ,Models, Molecular ,Stereochemistry ,Molecular Conformation ,chemistry.chemical_element ,Ethylenediamine ,Crystal structure ,010402 general chemistry ,Crystallography, X-Ray ,Ligands ,01 natural sciences ,Vibration ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Coordination Complexes ,Molecule ,Physical and Theoretical Chemistry ,010405 organic chemistry ,Hydrogen bond ,Organic Chemistry ,Temperature ,0104 chemical sciences ,Computer Science Applications ,Crystallography ,Computational Theory and Mathematics ,chemistry ,Octahedron ,13. Climate action ,Thermodynamics ,Single crystal ,Monoclinic crystal system - Abstract
The crystal structure of [Cr(edda)(acac)] (edda = ethylediamine-N,N'-diacetate; acac = acetylacetonato) has been determined by a single crystal X-ray diffraction study at 150 K. The chromium ion is in a distorted octahedral environment coordinated by two N and two O atoms of chelating edda and two O atoms of acac, resulting in s-cis configuration. The complex crystallizes in the space group P2(1)/c of the monoclinic system in a cell of dimensions a = 10.2588(9), b = 15.801(3), c = 8.7015(11) A, β =101.201(9)° and Z = 4. The mean Cr-N(edda), Cr-O(edda) and Cr-O(acac) bond distances are 2.0829(14), 1.9678(11) and 1.9477(11) A while the angles O-Cr-O of edda and O-Cr-O of acac are 171.47(5) and 92.72(5)°, respectively. The crystal structure is stabilized by N-H···O hydrogen bonds linking [Cr(edda)(acac)] molecules in distinct linear strands. The visible electronic and IR spectroscopic properties are also discussed. An improved, physically more realistic force field, Vibrationally Optimized Force Field (VOFF), capable of reproducing structural and vibrational properties of [Cr(edda)(acac)] was developed and its transferability demonstrated on selected chromium(III) complexes with similar ligands.
- Published
- 2011
32. Ligand field properties of the peptide nitrogen: The sharp-line electronic spectrum of mer-di(3-aminopropyl)amine(glycylglycinato-O,N,N′)-chromium(III)
- Author
-
Jong-Ha Choi and Patrick E. Hoggard
- Subjects
Ligand field theory ,Glycylglycine ,Inorganic chemistry ,chemistry.chemical_element ,Nitrogen ,Molecular electronic transition ,Inorganic Chemistry ,Crystallography ,Chromium ,chemistry.chemical_compound ,Perchlorate ,chemistry ,Materials Chemistry ,Amine gas treating ,Carboxylate ,Physical and Theoretical Chemistry - Abstract
An Angular Overlap Model calculation was used to fit the electronic spectrum, particularly the sharp-line positions, of [Cr(dpt)(glygly)]ClO 4 ·0.5C 4 H 6 N 2 O 2 ·2.5H 2 O [dpt = di(3-aminopropyl)amine, H 2 glygly = glycylglycine] at 77 K. An e π value of 502 cm −1 for the peptide nitrogen indicates that it is a weak net π-donor to chromium(III), presumably because donation from the filled π-orbital and back-donation to the empty π-antibonding orbital are almost in balance.
- Published
- 1992
33. Structural and spectroscopic properties of trans-dichlorobis(2,2-dimethyl-1,3-diaminopropane)chromium(III) chloride
- Author
-
Mohammad Hossein Habibi, Gary S. Nichol, Yu Chul Park, Sang Hak Lee, Jong-Ha Choi, and William Clegg
- Subjects
Denticity ,Absorption spectroscopy ,Spectrophotometry, Infrared ,Ligand ,Molecular Conformation ,chemistry.chemical_element ,Electrons ,Hydrogen Bonding ,Crystal structure ,Crystallography, X-Ray ,Ligands ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Bond length ,Chromium ,Crystallography ,chemistry ,Octahedron ,Chlorides ,Isomerism ,Chromium Compounds ,Organometallic Compounds ,Instrumentation ,Conformational isomerism ,Spectroscopy - Abstract
The structure of trans-[CrCl(2)(Me(2)tn)(2)]Cl (Me(2)tn=2,2-dimethylpropane-1,3-diamine) has been determined by a single-crystal X-ray diffraction study at 150K. The analysis reveals that there are two independent Cr(III) complex cations in the structure, one with crystallographic inversion symmetry and the other with two-fold rotation symmetry, which are conformational isomers of each other. In both conformations, the chromium atom adopts a distorted octahedral structure with the four nitrogen atoms of two Me(2)tn ligands occupying the equatorial plane and two chlorine atoms occupying trans-axial positions. The six-membered chelate rings are in stable chair conformations with N-Cr-N angles of 87.03(8) degrees and 88.99(8) degrees . The two chelate rings in the centrosymmetric complex cation 1 are anti, while those in the rotation-symmetric complex cation 2 are in syn conformations. The mean Cr-N and Cr-Cl bond lengths are 2.0922 and 2.3253 A, respectively. The infrared and UV-visible absorption spectra of trans-[CrCl(2)(Me(2)tn)(2)]Cl have also been measured. The resolved band maxima of the electronic d-d spectrum are fitted with a secular determinant for a quartet energy state of the d(3) configuration in a tetragonal field including configurational but neglecting spin-orbit coupling. It is confirmed that the nitrogen atoms of the Me(2)tn ligand have a strong sigma-donor character, but the chloro ligand has weak sigma- and pi-donor properties toward the chromium(III) ion.
- Published
- 2006
34. Crystal structure of bis[trans-dichloridobis-(propane-1,3-diamine-κ2N,N'chromium(III)] dichromate from synchrotron data.
- Author
-
Dohyun Moon, Keon Sang Ryoo, and Jong-Ha Choi
- Subjects
CRYSTAL structure ,PROPANE ,CHROMIUM - Abstract
The structure of the title compound, [CrCl
2 (tn)2 ]2 [Cr2 O7 ] (tn = propane-1,3-diamine; C3 H10 N2 ), has been determined from synchrotron data. The asymmetric unit contains one CrIII complex cation and half a [Cr2 O7 ]2- anion. In the complex cation, the CrIII ion is coordinated by the four N atoms of two propane-1,3-diamine (tn) ligands in the equatorial plane and by two Cl atoms in a trans configuration, displaying a distorted octahedral coordination sphere. The two six-membered rings in the complex cation have an anti chair-chair conformation with respect to each other. The mean Cr-N(tn) and Cr-Cl bond lengths are 2.09 (1) and 2.320 (2) Å, respectively. The slightly bent dichromate anion is disordered over two sets of sites (occupancy ratio = 0.7:0.3) and has a staggered conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the NH2 groups of the tn ligands as donors and the O atoms of the [Cr2 O7 ]2- anion and chlorido ligands as acceptors. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
35. Spectroscopic properties and ligand field analysis of cis-diazido(1,4,8,11-tetraazacyclotetradecane)chromium(III) azide
- Author
-
Jong-Ha Choi
- Subjects
Ligand field theory ,Chromium ,Azides ,Spectrophotometry, Infrared ,Infrared ,Ligand ,chemistry.chemical_element ,Photochemistry ,Ligands ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Absorption ,chemistry.chemical_compound ,Crystallography ,chemistry ,Cyclam ,Azide ,Emission spectrum ,Ground state ,Instrumentation ,Spectroscopy - Abstract
The emission and excitation spectra of cis-[Cr(cyclam)(N3)2](N3) (cyclam=1,4,8,11-tetraazacyclotetradecane) taken at 77 K are reported. The infrared and visible spectra at room temperature are also measured. The vibrational intervals due to the electronic ground state are extracted from the far-infrared and emission spectra. The ten electronic bands due to spin-allowed and spin-forbidden transitions are assigned. Using the observed transitions, a ligand field analysis has been performed to determine the bonding property of azido group in the chromium(III) complex. It is found that azide ligand has weak σ- and π-donor properties toward chromium(III) ion. The zero-phonon line in the excitation spectrum splits into two components by 249 cm−1, and the large 2Eg splitting can be reproduced by the ligand field theory.
- Published
- 2000
36. Dipotassium di-μ-hydroxo-bis[(nitrilotriacetato-κ4N,O,O′,O′′)chromium(III)] hexahydrate
- Author
-
Takayoshi Suzuki, Sumio Kaizaki, and Jong-Ha Choi
- Subjects
Bond length ,Crystallography ,Chromium ,Crystallographic point group ,Octahedron ,Chemistry ,chemistry.chemical_element ,General Materials Science ,General Chemistry ,Crystal structure ,Condensed Matter Physics ,Potassium Cation ,Ion - Abstract
The crystal structure of the title compound, K2[Cr2(C6H6NO6)2(OH)2]·6H2O or K2[Cr2(μ-OH)2(nta)2]·6H2O (nta = nitrilotriacetate), is composed of a dinuclear hydroxo-bridged chromium(III) complex anion, potassium cation and water molecules. Each CrIII ion is in a distorted octahedral environment and coordinated by one nitrogen and three carboxylate O atoms of the nta3− ligand plus two bridging hydroxo O atoms. The dinuclear complex anion possesses 2/m crystallographic symmetry. The Cr—O(μ-OH) bond lengths are 1.937 (4) and 1.951 (4) A. The Cr—N and Cr—O bond distances of the nta3− ligand are 2.054 (4) and 1.968 (3)–1.983 (3) A, while the HO—Cr—OH and Cr—OH—Cr angles are 80.46 (16) and 99.54 (16)°, respectively.
- Published
- 2003
37. Bis[trans-dichloridobis(propane-1,3-diamine-κ2 N,N′)chromium(III)] tetrachloridozincate determined using synchrotron radiation
- Author
-
Abdus Subhan, Dohyun Moon, and Jong-Ha Choi
- Subjects
Metal-Organic Papers ,biology ,Chemistry ,Hydrogen bond ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,biology.organism_classification ,Bioinformatics ,Chloride ,Ion ,Bond length ,Chromium ,Crystallography ,chemistry.chemical_compound ,Diamine ,Atom ,medicine ,Tetra ,General Materials Science ,medicine.drug - Abstract
In the title compound, [CrCl2(C3H10N2)2]2[ZnCl4], the CrIII atom is coordinated by four N atoms of propane-1,3-diamine (tn) and two Cl atoms in a trans arrangement, displaying a distorted octahedral geometry with crystallographic inversion symmetry; the Zn atom in the [ZnCl4]2− anion lies on a -4 axis. The orientations of the two six-membered chelate rings in the complex cation are in an anti chair–chair conformation with respect to each other. The Cr—N bond lengths are 2.087 (6) and 2.097 (6) Å. The Cr—Cl and Zn—Cl bond lengths are 2.3151 (16) and 2.3255 (13) Å, respectively. Weak intermolecular hydrogen bonds involving the tn NH2 groups as donors and chloride ligands of the anion and cation as acceptors are observed.
- Published
- 2012
38. trans-Dichloridobis(propane-1,3-diamine-κ2N,N′)chromium(III) perchlorate
- Author
-
Jong-Ha Choi and William Clegg
- Subjects
Hydrogen bond ,Ligand ,Chemistry ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,Chloride ,Bond length ,Perchlorate ,chemistry.chemical_compound ,Chromium ,Crystallography ,Diamine ,Alkane stereochemistry ,medicine ,General Materials Science ,medicine.drug - Abstract
In the title compound, [CrCl2(C3H10N2)2]ClO4, the CrIII atom is coordinated equatorially by four N atoms of two propane-1,3-diamine (tn) ligands and axially by two mutually trans Cl atoms, thus displaying a slightly distorted octahedral geometry with no crystallographically imposed symmetry. The two six-membered chair chelate rings in the complex cation are in an anti conformation with respect to each other. The Cr—N bond lengths range from 2.0831 (18) to 2.0917 (19) A, and the Cr—Cl bond lengths are 2.3148 (6) and 2.3135 (6) A. The perchlorate anions have slightly distorted tetrahedral geometries. Weak intermolecular hydrogen bonds involving the tn ligand NH groups as donors, and chloride ligands and anion O atoms as acceptors are observed.
- Published
- 2011
39. Synthesis, Characterization and Crystal Structure of trans-Aquahydroxobis(2,2-dimethyl-1,3-propanediamine)chromium(III) Diperchlorate.
- Author
-
Dohyun Moon, Chang-Seop Lee, Keon Sang Ryoo, and Jong-Ha Choi
- Subjects
CHROMIUM ,CHEMICAL synthesis ,CRYSTAL structure ,LIGANDS (Chemistry) ,ANIONS - Abstract
The article reports the synthesis, crystal structure and spectroscopic properties of the trans-anti [CR(Me,
2 tn)2 (OH)(H2 O)]-CIO4 )2 to elucidate the influence of O-donor ligands occupying the axial positions and counter anion. It shows that chromium atom is in a distorted octahedral environment coordinated by 2 biidetate, 2,2-dimethyl-1,3-propanediamine ligands and 2 O atoms of hydroxy group and water molecule in trans position.- Published
- 2014
- Full Text
- View/download PDF
40. trans-Dichloridobis(2,2-dimethylpropane-1,3-diamine-κ2N,N′)chromium(III) perchlorate
- Author
-
Jong-Ha Choi, Uk Lee, and Sang Hak Lee
- Subjects
Metal-Organic Papers ,chemistry.chemical_classification ,Hydrogen bond ,Salt (chemistry) ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,Bioinformatics ,Medicinal chemistry ,Ion ,Perchlorate ,chemistry.chemical_compound ,Chromium ,chemistry ,Diamine ,Atom ,General Materials Science ,Chelation - Abstract
In the title salt, [CrCl(2)(C(5)H(14)N(2))(2)]ClO(4), the Cr atom is in a trans-CrCl(2)N(4) octa-hedral environment comprising the four N atoms of two chelating 2,2-dimethyl-propane-1,3-diamine ligands and two Cl atoms. The two six-membered CrC(3)N(2) rings in the cation adopt anti chair-chair conformations with respect to each other. The perchlorate anion is disordered over two positions in respect of the Cl and an O atom in a 6:4 ratio. N-H⋯O hydrogen bonds link the cations and anions into a layer structure.
- Published
- 2008
41. Crystal Structure and Spectroscopic Properties of trans-Dibromobis(1,2-ethanediamine)chromium(III) Perchlorate.
- Author
-
Jong-Ha Choi, Clegg, William, Harrington, Ross, and Sang Lee
- Subjects
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CRYSTALLOGRAPHY , *CHEMICAL structure , *CHROMIUM , *SPECTRUM analysis , *BROMINE - Abstract
The crystal structure of trans-[Cr(en)2Br2]ClO4 (en = 1,2-ethanediamine) has been determined by a single-crystal X-ray diffraction study at 150 K. The complex crystallizes in the space group $$ P\overline{1} $$ of the triclinic system with two mononuclear formula units in a cell of dimensions a = 6.853(4), b = 8.109(5), c = 12.475(8) Å, α = 81.006(10)° , β = 77.005(10)° and γ = 74.981(10)°. The Cr atom is in a slightly distorted octahedral environment, coordinated by four nitrogen atoms of two en ligands and two bromine atoms in trans axial positions. The mean Cr–N(en) and Cr–Br bond lengths are 2.079(3) and 2.4743(10)Å, respectively. The five-membered rings are in stable gauche conformations with N1–Cr1–N2 and N3–Cr2–N4 angles of 82.81(11)° and 83.67(11)°, respectively. The crystal packing is stabilized by a network of N–H···O and N–H···Br hydrogen bonds. The infrared and electronic absorption spectra are consistent with the results of X-ray crystallography. The spectroscopic properties of the title complex are in good agreement with the result of X-ray crystallography, which shows that the chromium atom is in an octahedral environment, coordinated by two bidentate 1,2-ethanediamine ligands and two bromine atoms in trans positions.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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