Search

The crystal of a new tetrachlorocobalt(II) anion salt, [BzPy]2[CoCl4] (1) ([BzPy]+ = benzyl pyridinium), was grown by the slow evaporation solution growth method at room temperature. The salt 1 crystallizes in the monoclinic space group P2(1)/c and consists of two [BzPy]+ cations and one [CoCl4]2− anion in which the Co(II) ion is coordinated by four Cl atoms in a close to tetrahedral geometry. The crystal packing is stabilized by electrostatic interactions and C − H···Cl hydrogen bonds between [BzPy]+ cations and [CoCl4]2− anions. Powder XRD diffraction study confirms the crystalline nature and purity of the title compound. The Fourier transform infrared (FT-IR) spectrum was recorded and analyzed with the aid of DFT calculations in order to make a suitable assignment of the observed bands. The thermal stability of the hybrid crystal was analyzed by TG-DTA techniques revealing that the title crystal was stable up to 195 °C. The title salt exhibits violet and cyan fluorescence emissions upon excitation at 345 nm and weak antiferromagnetic interactions in the temperature range 2-300 K. The nonlinear optical (NLO) effect of this compound was predicted using DFT, suggesting that the title crystal is a good material for NLO applications. [ABSTRACT FROM AUTHOR]

Abstract Different structures and different Ag+-response behaviors of a pair of pyrene-based S-containing atropisomers, namely s -BSPPy and a -BSPPy , have been investigated. The calculated high rotation barrier indicates that the two atropisomers are non-interconvertible. In polar solvents, s -BSPPy exhibits excimer emission but a -BSPPy does not. Based on the X-ray structures and the DFT calculated intermolecular interactions, the excimer of s -BSPPy is suggested to take a non-parallel edge-to-face λ -shaped geometry. Especially, s -BSPPy exhibits ratiometric excimer-off and monomer-on emission as a unique response to Ag+ in solutions, while no ratiometric Ag+-response was observed for a -BSPPy. Graphical abstract Unlabelled Image Highlights • In solution, s -BSPPy exhibits excimer emission, a -BSPPy does not. • Edge-to-face λ -shaped excimer of s -BSPPy. • s -BSPPy shows excimer-to-monomer emission in response to Ag+, a -BSPPy does not. • s -BSPPy and a -BSPPy atropisomers are non-interconvertible. [ABSTRACT FROM AUTHOR]

Four novel manganese phosphonate clusters, namely Cl@[Mn6(t-BuPO3)8(H2O)2(CH3OH)4][OH] (1), Br@[Mn6(t-BuPO3)8(H2O)2(CH3OH)4][OH]·4H2O (2), [Mn13O6(t-BuPO3)10(OH)6(CH3OH)6][Mn13O6(t-BuPO3)10(OCH3)6(t-BuPO3H2)2(H2O)4]·2CH3OH·10H2O (3) and [Mn15K2O8(t-BuPO3)10(CH3O)4(C6H5COO)4(H2O)8]·6H2O (4), have been successfully synthesized in the presence of tert-butylphosphonic acid, carboxylic acid, NBun4MnO4 and different manganese sources. These clusters were characterized by elemental analyses, IR spectroscopy, thermogravimetric (TG) analyses and single-crystal X-ray diffraction. Single-crystal structure analyses reveal that the structures of 1–4 are diverse. The structure of cluster 1 is analogous to that of cluster 2, which displays a cage-like arrangement with one halide ion (Cl−, Br−) lying inside the centre of the cave. Cluster 3 is a carboxylate-free manganese phosphonate cluster consisting of two similar Mn13 structural units. Moreover, there exist two potassium ions and fifteen manganese ions in the heterometallic cluster 4. In addition, solid-state DC magnetic susceptibility measurements indicate the existence of overall antiferromagnetic (AF) exchange interactions between the Mn ions in all clusters. [ABSTRACT FROM AUTHOR]

Abstract: A series of Ln(III)-Ag(I) 4d–4f heterometallic coordination polymers [LnAg(oba)2(H2O)]n (Ln=Dy 1, Ho 2, Er 3) have been synthesized under hydrothermal reactions of 4,4′-oxybis(benzoicacid) (H2oba) with Ln(NO3)3 ·6H2O and AgNO3 at 180°C. All complexes are isostructural with 3D networks expanded from 1D zigzag chains and 2D layers. In addition, the luminescent property of compound 1 was investigated in the solid-state at room temperature. [Copyright &y& Elsevier]

Abstract: Two different types of novel lanthanide coordination polymers constructed from 5-nitroisophthalic acid, and picolinic acid as auxiliary ligand, namely, {[Ln2(nip)2(pic)2(H2O)]}n (type I, Ln=Pr 1, Nd 2, Sm 3, Eu 4, and H2nip=5-nitroisophthalic acid, Hpic=picolinic acid), and {[Ln4(nip)5(pic)2(H2O)2]·2H2O}n (type II, Ln=Tb 5, Dy 6, Ho 7, Er 8), have been hydrothermally synthesized and characterized by IR, elemental analysis, thermogravimetric analysis (TGA), single-crystal X-ray diffraction analyses and powder X-ray diffraction (PXRD). Complexes 1–4 (type I) are isostructural and the infinite 1D Sm-carboxylate chains are bridged by pia ligands to form 2D sheets, such sheets are further united together to generate a 3D supramolecular structure. Complexes 5–8 (type II) are isostructural and the infinite 1D Tb–carboxylate chains are bridged by pia ligands to form 2D sheets, such sheets are further united together to generate a 3D supramolecular structure. Furthermore, the luminescence properties of compounds 4 and 5 have also been studied. [Copyright &y& Elsevier]

In this article, we present the syntheses, crystal structures, vibrational spectra, optical and antibacterial properties of two new organic-inorganic hybrids, [Py(CH2)3TPP][CoCl4]·H2O (1) and [Py(CH2)3TPP][CuCl4] (2), where [Py(CH2)3TPP]2+ was 1-(1′-pyridyl-propyl)-3-triphenyl phosphonium. Two hybrids were crystallized in the monoclinic space group P21/n. The hybrids consisted of a [Py(CH2)3TPP]2+ cation and a tetrahedral [CoCl4]2−/[CuCl4]2− anion, where the crystal structure was stabilized by C−H···Cl, O−H···Cl, and C−H···O hydrogen bonds due to the presence of a water molecule in 1, and the crystal structure of 2 was stabilized by C−H···Cl hydrogen bonds. Experimental vibrational bands (IR and Raman) have been discussed and assigned. The intermolecular energy, the energy gap between HOMO and LUMO orbitals, as well as the first hyperpolarizabilities were predicted based on DFT calculations. The low energy gaps (1.26 eV for 1 and 1.20 eV for 2) were responsible for the charge transfer interactions that eventually occur between the cation and anion. The first hyperpolarizabilities (βtot) of 1 and 2 were 82 and 237 times as high as that of the standard KDP crystal, respectively, indicating that the as-prepared hybrids were excellent materials for NLO applications. Furthermore, it was found that both salts exhibit good bactericidal activity against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Graphical abstract An organic–inorganic hybrid crystal 1-benzyl-4′-aminopyridinium tetrachlorocadmate(II) was synthesized successfully and characterized by single crystal XRD, powder XRD and TG-DTA-MS technique. Theoretical calculations were performed using density functional theory (DFT) for studying the molecular structure, intermolecular energy, UV–Vis, vibrational spectra and nonlinear optical (NLO) properties of the title crystal. Further, the title compound exhibits strong fluorescence emission at 394, 329 and 467 nm in the solid at room temperature. Abstract An organic–inorganic hybrid crystal, [Bz-4-NH 2 Py] 2 [CdBr 4 ](1) (Bz-4-NH 2 Py = 1-benzyl-4′-aminopyridinium), was grown successfully by slow evaporation solution growth method at room temperature and characterized. In tetrachlorocadmate(II) dianion, the CdII ion is coordinated by four Br atoms in a close to tetrahedral geometry. The crystal packing is stabilized by C H⋯Br hydrogen bonds between [Bz-4-NH 2 Py]+ cations and [CdBr 4 ]2− anion forming a three-dimensional network. Powder XRD diffraction study confirms the crystalline nature of the title compound. Thermal stability and the gaseous products of decomposition at 362 °C were examined by TG-DTA-MS technique. The Fourier transform infrared (FT-IR) and Raman spectra were recorded and analyzed with the aid of DFT calculations in order to make a suitable assignment of the observed bands. UV–Vis spectral analysis was used to determine the band gap energy, and the nonlinear optical (NLO) effect of the compound was predicted using DFT. Further, the title compound exhibits strong fluorescence emission at 394, 329 and 467 nm in the solid at room temperature. [ABSTRACT FROM AUTHOR]

A novel zero‐dimensional dinuclear zinc complex, di‐μ‐acetato‐1:2κ4O:O′‐(μ‐2‐acetyl‐6‐{[(Z)‐2‐bromo‐3‐oxoprop‐1‐en‐1‐yl]azanidyl}phenolato‐1κ2O1,O2:2κ3O1,N,O6)(N,N‐dimethylacetamide‐1κO)dizinc(II), [Zn2(C11H8BrNO3)(CH3COO)2(C4H9NO)] or [Zn2(L)(CH3COO)2(DMA)], 1, was synthesized using (Z)‐3‐[(3‐acetyl‐2‐hydroxyphenyl)amino]‐2‐bromoprop‐2‐enal (H2L), which was synthesized from 1‐(3‐amino‐2‐hydroxyphenyl)ethanone and 2‐bromomalonaldehyde. H2L and 1 were characterized by single‐crystal X‐ray diffraction, FT–IR spectroscopy and elemental analysis. Theoretical calculations of the bond orders and excited state of H2L confirmed that there is extensive electron delocalization in the H2L molecules. Single‐crystal X‐ray diffraction shows that the two Zn atoms are pentacoordinated in distorted trigonal bipyramidal configurations in the crystals of 1. The thermogravimetric analysis of 1 shows that the main frame of the complex remains stable to about 190 °C. Powder X‐ray diffraction (PXRD) analysis shows that 1 possesses high purity and acid and alkali resistance. The intermolecular interactions of H2L and 1 were analyzed using Hirshfeld surface analysis and the results indicate that the H...H and O...H interactions of H2L and 1 play a considerable role in stabilizing the self‐assembly process. [ABSTRACT FROM AUTHOR]

Three 1-phenylindolin-2-one derivatives, namely 1-phenylindolin-2-one, C14H11NO, (I), 5-bromo-1-phenylindolin-2-one, C14H10BrNO, (II), and 5-iodo-1-phenylindolin-2-one, C14H10INO, (III), have been synthesized and their structures determined. Compounds (I) and (II) crystallized in the centrosymmetric space groups Pbca and P21/ c, respectively, while compound (III) crystallized in the polar space group Aea2. Density functional theory (DFT) calculations show that the molecular dipole moment gradually decreases in the order (I) > (II) > (III). The relatively smaller dipole moment of (III) and the larger non-electrostatic intermolecular interactions may be the main reasons for the noncentrosymmetric and polar structure of (III). [ABSTRACT FROM AUTHOR]

3-hydroxyacyl-CoA dehydrogenase (HAD, EC 1.1.1.35) is a homodimeric enzyme localized in the mitochondrial matrix, which catalyzes the third step in fatty acid β-oxidation. The crystal structures of human HAD and subsequent complexes with cofactor/substrate enabled better understanding of HAD catalytic mechanism. However, numerous human diseases were found related to mutations at HAD dimerization interface that is away from the catalytic pocket. The role of HAD dimerization in its catalytic activity needs to be elucidated. Here, we solved the crystal structure of Caenorhabditis elegans HAD (cHAD) that is highly conserved to human HAD. Even though the cHAD mutants (R204A, Y209A and R204A/Y209A) with attenuated interactions on the dimerization interface still maintain a dimerization form, their enzymatic activities significantly decrease compared to that of the wild type. Such reduced activities are in consistency with the reduced ratios of the catalytic intermediate formation. Further molecular dynamics simulations results reveal that the alteration of the dimerization interface will increase the fluctuation of a distal region (a.a. 60–80) that plays an important role in the substrate binding. The increased fluctuation decreases the stability of the catalytic intermediate formation, and therefore the enzymatic activity is attenuated. Our study reveals the molecular mechanism about the essential role of the HAD dimerization interface in its catalytic activity via allosteric effects. [ABSTRACT FROM AUTHOR]

A new organic hybrid material, 2,4-dichlorobenzyl triphenylphosphinium picrate, [2Cl4ClBzTPP][PIC](1), has been grown by slow evaporation solution growth technique, and characterized by elemental analysis, spectroscopy, thermal analysis, powder and single crystal XRD. The composite belongs to monoclinic system with space group P 2(1)/ c , and consists of a pair of [2Cl4ClBzTPP]+ cations and picrate anions. The experimental vibrational bands (IR and Raman) have been discussed and assigned based on DFT calculations. The HOMO-LUMO energy gap explains the charge transfer interactions in the molecule. TG-TDA technique reveals that the title crystal was stable up to 168 °C. The fluorescence spectra reveal that the compound shows violet and green fluorescence emissions at 377 and 509 nm upon excitation at 250 nm in solid state at room temperature. The energy of weak interactions in the molecule and nonlinear optical properties were studied using DFT calculations. Image 1 • A organic crystal of substituted benzyl triphenylphosphinium picrate salt was synthesized and characterized. • The experimental vibrational bands (IR and Raman) have been discussed and assigned based on DFT calculations. • The HOMO-LUMO energy gap explains the charge transfer interactions in the molecule. • The energy of weak interactions in the molecule and nonlinear optical properties were studies using DFT calculations. • The title crystal show violet and green fluorescence emissions at 377 and 509 nm in solid state at room temperature. [ABSTRACT FROM AUTHOR]

In recent years, organic–inorganic hybrid metal halides have emerged as a highly promising class of semiconducting light emitting diodes (LEDs) due to their fascinating photoluminescence properties. Here, by specifically selecting different organic cations as templates, a series of new hybrid cuprous halides have been solvothermally prepared, namely [Me-Py]CuI2 (1), [(Me)2-DABCO]Cu2I4 (2), [Me-MePy]Cu2I3 (3), and [H2DABCO]Cu3X5 (X = I (4) and Br (5)). These hybrid cuprous halides feature one-dimensional (1D) [CuI2]−, [Cu2I3]− and [Cu3X5]2− (X = Br, I) chains surrounded and charge-balanced by organic cations. Under UV photoexcitation, these hybrid cuprous halides exhibit strong tunable photoluminescence from cyan (480 nm) to red (675 nm) emissions with large Stokes shifts (345 nm). The intrinsic nature of PL emissions is also investigated based on temperature-dependent PL emission, lifetime, photoluminescence quantum efficiencies, etc. [ABSTRACT FROM AUTHOR]

C26H24N2NiO6, hexagonal, P6522 (no. 179), a = b = 11.0161(4) Å, c = 33.1459(8) Å, V = 3483.5(9) Å3, Z = 6, Rgt (F) = 0.0376, wRref (F2 ) = 0.0879, T = 295 K. [ABSTRACT FROM AUTHOR]

The hydrothermal reaction of rare earth nitrates, CuCN, 2,7-naphthalenedisulfonate (2,7-nds), and isonicotinic acid (Hina) affords a new family of 3-D heterometallic 3d–4f coordination polymers, [Ln2Cu(2,7-nds)2(ina)4(H2O)4]·4H2O (Ln = Nd (1), Sm (2), Eu (3), Gd (4); 2,7-nds = 2,7-naphthalenedisulfonate, Hina = isonicotinic acid). Complexes1–4are structurally characterized by single crystal X-ray diffraction, elemental analysis, FT-IR spectroscopy (IR), powder X-ray diffraction, and thermogravimetric analyses. X-ray crystal structure analyses reveal that1–4are isomorphous with dinuclear subunit [Sm2(ina)4] binding Cu ions to generate 2-D networks. Such 2-D networks are pillared by linking 2,7-nds ligands to result in the 3-D layer-pillared Ln(III)–Cu(II) coordination architectures. The valence of Cu salts changed in the reaction. In addition, the luminescence properties of1–3and the magnetic properties of3and4have also been investigated. [ABSTRACT FROM PUBLISHER]

Two kinds of three-dimensional (3D) coordination frameworks from monometallic to heterometallic, including a charming 3D monometallic complex, namely, [Eu2(mpda)3(H2O)4]n (1) and the first series of novel 3D heterometallic 4d-4f coordination frameworks based on 2,6-dimethylpyridine-3,5-dicarboxylic acid, namely, [Ln2Cd2(mpda)2(bdc)2(SO4)2(H2O)6]n [Ln=Sm(2), Eu(3), Gd(4), Tb(5), Dy(6); mpda=2,6-dimethylpyridine-3,5-dicarboxylic acid; bdc=1,4-benzenedicarboxylic acid] have been successfully synthesized under hydrothermal conditions and structurally characterized. Crystal 1 is featured by its interesting 3D chain-layer construction which is formed by the alternative arrangement of chains and layers and exhibits 2-nodal 5, 6-connected 3D network with the Schlafli symbol of {33.43.55.64}{36.46.53}. Complexes 2-6 are isostructural and it reveals that these 3D heterometallic compounds are firstly built by H2mpda ligand. What is worth mentioning is that anionic ligand SO42− plays a crucial function in the construction building. The two-dimensional (2D) lanthanide-transition heterometallic bilayers [Ln2Cd2(mpda)2(bdc)2]n are pillared by SO42− subunits forming mixed-ligand complexes with a pillared-layer 3D structure. Complexes 2-6 feature 4-nodal 3, 4, 5, 6-connected 3D frameworks with {4.82}{4.84.10}{42.810.102.12}{42.88} topology. All the complexes are characterized by elemental analyses, FT-IR spectroscopy, Powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Furthermore, the luminescence properties of compounds 1, 3, and 5 and the magnetic properties of complexes 4 and 6 were also investigated in detail. [ABSTRACT FROM AUTHOR]

Abstract: The first example of 3D heterometallic 4d–4f 2,7-naphthanlenedisulfonate compounds [LnAg2(2,7-NDS)(IN)3] (Ln=Sm (1), Eu (2), Gd (3), Tb (4), Dy(5); 2,7-NDS=2,7-naphthanlenedisulfonate; IN=isonicotinic acid) has been synthesized via hydrothermal reaction and characterized by single crystal X-ray diffraction, elemental analyses, FT-IR spectroscopy, powder X-ray diffraction(PXRD) and thermogravimetric analyses (TGA). X-Ray structural analysis reveals that compounds 1–5 exhibit same well-organized 3D coordination frameworks that are built up by 2D elliptical cylinder shaped [LnAg2(2,7-NDS)(IN)3] layers which are constructed by 1D anionic chains [Ln(2,7-NDS)(IN)3]2− linking the adjacent Ag(I) ions, and [LnAg(μ2-O)2] units, possessing a 7-connected topology with the Schläfli symbol of {33;411;56;6}. Furthermore, the luminescence properties of compounds 2 and 4 and the magnetic properties of compounds 3 and 5 were investigated. [Copyright &y& Elsevier]