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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]

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]

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]

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]