Search

Two new Schiff base ligands of HLBr and HLCl with the general formula C4H4-OHC6H3C=NCH2CH2X (X = Br, Cl) and their Mn(II) and Cu(II) complexes (1, 2, 3, and 4) are synthesized. Different characterization methods, such as the elemental analysis (CHN), 1H NMR and FT-IR spectroscopy, and the single crystal X-ray diffraction analysis are used to determine the composition, functional groups and crystal structures of the investigated compounds. The titled Schiff base ligands crystallize in the monoclinic system with the space group P21/c. The crystal packing of Schiff bases is stabilized by N-H⋯O and C-H⋯O hydrogen bonds. The Schiff bases are coordinated to Mn(II) and Cu(II) ion centers via two different donor atoms (nitrogen and oxygen) and form bis-chelate complexes M(LX)2 (1–4) in an approximately square planar coordination geometry. Complexes 1, 2, and 4 crystallize in the monoclinic system with the space group P21/c. [ABSTRACT FROM AUTHOR]

In this paper, bis-monodentate Schiff base ligand (2,4-Cl-ba)2bn and its 1D copper(I) coordination polymer [Cu2(μ-(2,4-Cl-ba)2bn)(μ-I2)]n are synthesized and characterized by the elemental analysis (CHN), FT-IR and 1H NMR spectroscopy. Their crystal structure is determined from the single crystal X-ray diffraction analysis. The thermal behavior of the complex is studied using thermogravimetry in order to evaluate its thermal stability and thermal decomposition pathway. The X-ray results show that the free Schiff base ligand (2,4-Cl-ba)2bn is centrosymmetric and coordinated to copper(I) ions via two iminic nitrogen atoms as a bis-monodentate bridging ligand. The coordination geometry around the copper ions is a distorted triangle formed by one nitrogen and two iodine atoms. The distance between the two symmetry-related copper atoms is very short: 2.4756(8) Å. [ABSTRACT FROM AUTHOR]

The experimental crystal structure of a Schiff base compound 4-bromo-2-(4,6-dichloro-phenylimino)-phenol 1 is determined by single crystal X-ray diffraction and also characterized by FT-IR and 1H NMR spectroscopy. The electronic structure in the gas phase is studied by density functional theory (DFT) calculations.The theoretical results have good agreement with the data obtained from the crystallographic analysis. In addition, theoretical configurations which refer to the title compound are relaxed and studied in terms of the combined analysis of HOMO-LUMO energy gap, total density of states (DOS), partial density of state (PDOS), overlap population density of state (OPDOS), molecular electrostatic potential (MEP), NMR spectra, and harmonic vibrational frequencies. [ABSTRACT FROM AUTHOR]

In the present study, we report the structure of one new phosphoramidate counter ion. The single crystal X-ray diffraction analysis revealed that C18H18N3O4P1, consists of a discrete [C18H18N2OP]+ cation and NO3− anion. The compound crystallizes in triclinic system, space group P-1, unit cell a = 9.4935 Å, b = 10.4556(4) Å, c = 11.1560(3) Å, α = 63.951(3)°, β = 67.039(3)°, γ = 66.017(3)°. The interaction between cation and anion has occurred through hydrogen bonding. The strength of different hydrogen bonds between two counter ions was studied by DFT calculations in the gas phase. We optimized the hydrogen atoms and kept all other atoms invariant in the optimization process. The H-optimized systems included one nitrate anion and one phosphoramide cation which were connected by special intermolecular interactions. The binding energies of these interactions were calculated (M062X/6-311G*) and corrected for the basis set superposition error (BSSE) using by counterpoise (CP) procedure. Moreover, the main noncovalent inter-molecular interactions were studied by Hirshfeld surface analysis and finger print plots. [ABSTRACT FROM AUTHOR]

Metal-free organic compounds 24-SC (( E)-2-cyano-3-(2,4-dimethoxyphenyl)acrylic acid) and 34-SC (( E)-2-cyano-3-(3,4-dimethoxyphenyl)acrylic acid), containing methoxy groups as a donor and the acrylic acid as an acceptor were synthesized and characterized by CHN, FT-IR, UV-Vis, H-NMR and single crystal X-ray diffraction and used as photosensitizers for the application of dye-sensitized solar cells (DSSC). The sensitizing characteristics of them were evaluated. Both compounds contain the natural molecule, its anionic form and the piperidinium cation and they differ by number of these molecules in the asymmetric unit. To get further insight into the effect of molecular structure on the performance of DSSC, their geometry and energies of HOMO and LUMO were optimized by density functional theory calculation at the B3LYP/6-31G(d) level with Gaussian 03. Overall conversion efficiencies of 0.78 under full sunlight irradiation are obtained for DSSCs based on the new metal-free organic dyes 24-SC and 34-SC. [ABSTRACT FROM AUTHOR]

In this paper, we report the preparation of a four-coordinated copper(I) thiosemicarbazone complex [CuI(PPh)(catsc)] from the reaction of PPh and catsc (3-phenylpropenalthiosemicarbazone) with CuI. The synthesized complex is characterized by elemental analyses (CHNS) and FT-IR spectroscopy. The crystal structure of [CuI(PPh)(catsc)] is investigated by single crystal X-ray diffraction. The catsc coordinates to the copper(I) ion as a bidentate ligand via the N and S atoms. The complex has a distorted tetrahedral coordination geometry. [ABSTRACT FROM AUTHOR]

The reaction of 1,4-diaminobutane with 2,2′-diformyl-6,6′-dimethoxy-diphenoxypropane in a mixed solvent of methanol and chloroform results in a new 17-membered macrocyclic Schiff base compound MeO-sal-pn-pn. The title compound is characterized by the elemental analysis (CHN), FT-IR, H NMR spectroscopy, and powder X-ray diffraction. The crystal data are: M = 396.5, orthorhombic, P222, with unit cell parameters: a = 4.71769(3) Å, b = 19.1524(2) Å, c = 22.9418(2) Å, V = 2072.90(3) Å, and Z = 4. [ABSTRACT FROM AUTHOR]

A mixed ligand copper(I) Schiff base complex [Cu(py-Clan)(PPh)I], where py-Clan = = 4-chlorophenylpyridine-2-ylmethyleneamine, is synthesized and structurally characterized by single crystal X-ray crystallography. In this complex, the copper(I) ion is in a distorted four-coordinate tetrahedral geometry. The Schiff base py-Clan ligand acts as a chelating ligand and coordinates to the copper center via two nitrogen atoms. The [Cu(py-Clan)(PPh)I] complex crystallizes in the monoclinic space group P2/ c with unit cell parameters: a = 10.3339(12) Å, b = 34.524 Å, c = 8.3940 Å, β = 114.759(8)°, V = 2719.4(5) Å and Z = 4. [ABSTRACT FROM AUTHOR]

Three one-dimensional mercury(II) complexes, [Hg 2(μ N,N-((Me 2N-Ba) 2Bn)(μ-X) 2X 2] n, where X = Cl ( I), Br ( II), and I ( III), (Me 2N-Ba) 2Bn = N,N′-bis(dimethylaminobenzylidene)butane-1,4-diamine, involving a bidentate Schiff base with a flexible spacer (=N-C-C-C-C-N=) were prepared under mild condition and characterized by elemental analyses (CHN), FT-IR, 1H & 13C-NMR spectroscopy. The crystal structure of II has been determined by X-ray single-crystal diffraction. Each Hg(II) center adopts a distorted [HgNBr 3] tetrahedron environment arising from two crystallographically equivalent (Me 2N-Ba) 2Bn Schiff base ligands. Each of ligands acts as N 2-bis-chelating ligand with the nitrogen atoms of two imine functions in anti-form leading to the dinuclear [Hg 2(μ N,N-(Me 2N-Ba) 2Bn)Br 2] groups. Such dinuclear [Hg 2(μ N,N-((Me 2Nvg-Ba) 2Bn)Br 2] groups are bridged two iodine anions (μ-Br) 2 to form a neutral 1D-chain mercury ( II) coordination polymer. [ABSTRACT FROM AUTHOR]

In this study four coordinated complexes of zinc(II) halides with a new symmetrical bidentate Schiff base ligand (2,5-MeO-ba)En are synthesized and characterized. The metal to ligand ratio of the complexes is found to be 1:1 with the formula of Zn((2,5-MeO-ba)En)X (X = Cl ( 1), Br ( 2), I ( 3)). The crystal structure of the Schiff base ligand (2,5-MeO-ba)En is determined by X-ray crystallography from single crystal data. Also, the optimized geometries of the Schiff base ligand (2,5-MeO-ba)En and its zinc(II) complexes are calculated using the density functional theory method (B3LYP/6-31G). The obtained structural parameters of (2,5-MeO-ba)En are in agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The Schiff base compounds N,N′-bis(3,4-dimethoxybenzylidene)-2,2-dimethylpropane-1,3-diamine hydrate, (3,4-MeO-ba)Mepn.HO ( 1), and N,N′-bis(3,4-dimethoxybenzylidene)butane-1,4-diamine, (3,4-MeO-ba)bn ( 2), with different central groups derived from 3,4-dimethoxybenzaldehyde are synthesized and characterized by elemental analysis, FT-IR and H NMR spectroscopy. The crystal structure of 1 is determined by single crystal X-ray diffraction. Each imino functional group (-C=N-) is coplanar with its adjacent benzene ring and the two benzene rings form a dihedral angle of 86.868(27)°. Title compound 1 crystallizes in the monoclinic space group P2/ n with unit cell parameters: a = 9.0774(2) Å, b = 29.2138(5) Å, c = 8.5696(2) Å, β = 92.4756(14)°, V = 2270.41(8) Å and Z = 4. [ABSTRACT FROM AUTHOR]

Mononuclear mercury(II) complex [Hg((2,3,4-MeO-Ba)En)I] ( I), where (2,3,4-MeO-Ba)En = N,N′-bis(2,3,4-trimethoxybenzaldehyde)ethylenediimine, has been synthesized and characterized by elemental analysis (C, H, and N) and confirmed by single-crystal X-ray diffraction analysis. The complex I crystallizes in the monoclinic system, with space group C2/ c, having one symmetry-independent Hg ion coordinated in distorted tetrahedral geometry by two N atoms of the Schiff base ligand and by two I atoms. The Schiff base ligand (2,3,4-MeO-Ba)En acts as a chelating ligand and coordinates via two N atoms to the mercury center and adopts an ( E,E) conformation. [ABSTRACT FROM AUTHOR]

Mercury(II) complex, [Hg((3,4-MeO-Bza)En)I] ( I), where (3,4-MeO-Bza)En = N,N′-bis(3,4-dimethoxybenzaldehyde)ethylenediimine, has been synthesized from the reaction of HgI with (3,4-MeO-Bza)En in methanol as solvent at 50°C. It was characterized by elemental analysis (CHN), H-NMR spectroscopy and confirmed by single-crystal X-ray diffraction analysis. The complex I crystallizes in the monoclinic system, with space group P2/c, having one symmetry-independent Hg ion coordinated in a distorted tetrahedral geometry by two N atoms of the Schiff base ligand and by two I atoms. The Schiff base ligand (3,4-MeO-Bza)En acts as a chelating ligand and coordinates via two N atoms to the mercury center. It adopts an ( E, E) conformation. [ABSTRACT FROM AUTHOR]

New diphosphates AErPO, A = Rb ( 1), Cs ( 2), and HEuPO·3HO ( 3) have been prepared via soft chemistry route from evaporation of aqueous solution. Their crystal structures have been solved by single crystal diffraction data. The compounds ( 1) and ( 2) crystallize in the monoclinic space group P2/ c with the following unit cell dimensions: ( 1) a = 7.7248(4) Å, b = 10.9342(6) Å, c = 8.6716(3) Å, β = 105.434(4)° and Z = 4; ( 2) a = 7.9192(4) Å, b = 10.8606(4) Å, c = 8.7684(5) Å, β = 104.317(5)° and Z = 4. Compound ( 3) crystallises in the triclinic space group P − 1, with the unit cell parameters: a = 6.4036(5) Å, b = 6.8753(6) Å, c = 9.7964(8) Å, α = 81.706(7)°, β = 80.218(7)°, γ = 88.381(7)°. Crystal structure of ( 1) and ( 2) consists of 3D open framework built from [ErO] octahedra sharing corners with [PO] units, leading to the formation of channels running along c direction in which A [A = Rb(1), Cs(2)] ions are located. The compound ( 3), on the other hand, exhibits a lamellar structure, in which edge-sharing polyhedra of eightfold coordinated europium form chains along [010]. These chains are joined in turn to each others using diphosphates bridges. A network of O-H···O hydrogen bonds reinforces the cohesion of the structure of ( 3). The diphosphate groups in ( 1), ( 2) and ( 3) adopts an eclipsed configuration. IR and Raman spectra of the three new phosphates show usual signals related to the PO diphosphate group and the water molecule. TG and DTA studies were carried out on crystals of ( 3). The data are correlated to the crystal structures ones. Graphical Abstract: Edge-sharing [LnO] polyhedra (here Ln is Eu) lead to ladder channels in the crystal structure of HEuPO·3HO. These channels are linked through O-P-O bridges from the diphsophates groups and an intricate H-bonds network to build a lamellar structure. Crystal structure of AErPO, A is Rb or Cs consists of a three dimensional open framework, built from octa-coordinated Er which share corners with diphosphates groups. These channels run through the monoclinic cell along c, in which the nonovalent cations are located.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The new mononuclear mercury(II) complex [Hg((Me-Ca)En)Br] ( I), where (Me-Ca)En = N, N,N′- bis[( E)-2-benzylidenepropylidene]ethane-1,2-diamine, has been synthesized and characterized. The crystal and molecular structure of I was determined by X-ray crystallography from single-crystal data. The complex I crystallizes in the monoclinic system, having one symmetry-independent Hg ion coordinated in distorted tetrahedral geometry by two N atoms of the Schiff base ligand and by two Br atoms. This structure contains intermolecular non-classical hydrogen bonds of the type C-H...Br. [ABSTRACT FROM AUTHOR]

The reaction of 3,4-dimethoxybenzaldehyde with 4-chloroaniline (1:1 molar ration) leads to the formation of a new Schiff base ( E)-4-chloro- N-(3,4-dimethoxybenzylidene)aniline ( 1) that is successfully obtained and characterized by elemental analyses, FT-IR and H NMR spectroscopy, and single crystal X-ray diffraction. The strong absorption band at 1620 cm in the FT-IR spectrum and a singlet signal at 8.32 ppm in the H NMR spectrum of 1 clearly proves the presence of the C=N (azomethine) group. Single crystal X-ray analyses reveal that the title compound adopts an E configuration with respect to the C=N bond. [ABSTRACT FROM AUTHOR]

The new manganese(III) complex, Mn(Salhn)(CHOH)(N), where Salhn = N,N′-bis(salicylidene)-1,2-hexanediamine, was prepared from a reaction mixture containing Salhn, MnCl · 2HO, and NaN (2: 1: 8 molar ratio) in methanol and characterized using elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction. In the title complex, the Mn(III) center is in a distorted octahedral coordination geometry with the basal plane formed by the NO donors of the tetradentate Schiff base dianion; the two phenolate O atoms and the two imine N atoms are each mutually in the cis position. The azide ion and the O atom of the methanol molecule occupy the other two positions of the octahedron. The hydrogen bond O(3)-H(3O)⋯N(5) links the mononuclear Mn(Salhn)(CHOH)(N) units into a 1D chain extended along the x axis. The crystal structure is further stabilized by C(7)-H(7)⋯N(3) and C(16)-H(16)⋯N(5) hydrogen bonds. [ABSTRACT FROM AUTHOR]

The Schiff-base compound N,N′-Bis-(2,5-dimethoxybenzylidene)-1,3-diaminopropan, (2,5-MeO-ba)pn, is synthesized and characterized by elemental analysis, FT-IR and H NMR spectroscopy. The crystal structure of (2,5-MeO-ba)pn is determined by X-ray single crystal diffraction analysis. The X-ray diffraction analysis at 120 K reveals that (2,5-MeO-ba)pn crystallizes in the orthorhombic system, Fdd2 space group with a = 29.339(9) Å, b = 29.4073(11) Å, c = 4.4524(2) Å, V = 3840.8(3) Å, μ = 0.72 mm, and Z = 8. [ABSTRACT FROM AUTHOR]