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A new hybrid inorganic-organic compound [Cu( Hdien ) 2 (H 2 O) 2 ]( pnb ) 4 ·4H 2 O ( 1 ) (where pnb = p -nitrobenzoate), in which the tridentate ligand diethylenetriamine ( dien ) shows an unusual coordination behavior acting as a bidentate ligand when present in its monoprotonated form ( Hdien + ) has been synthesized by the reaction of copper(II) p -nitrobenzoate and slight excess of dien in methanol-water mixture (4:1v/v). Re-crystallization of the violet precipitated product from hot water gave single crystals suitable for X-ray diffraction studies. The newly synthesized compound 1 has been characterized by spectroscopic techniques (UV–Vis, FT-IR, EPR), and theoretical methods (DFT and MRCI/SORCI). Single crystal X-ray structure determination revealed the existence of the cationic species [Cu( Hdien ) 2 (H 2 O) 2 ] 4+ , four p -nitrobenzoate as counter anions and four water molecules are present as solvent of crystallization. Packing analyses of title compound as well as of the structurally similar [Cu( en ) 2 (H 2 O) 2 ]( pnb ) 2, 2 has shown similarities in the crystalline architecture that both hybrid inorganic-organic compounds is stabilized by various non-covalent interactions such as N-H⋯O, C-H⋯O, O-H⋯O etc. [ABSTRACT FROM AUTHOR]

Abstract: The solid-state supramolecular structure of 6-methylisocytosine dihydrogen monophosphate adduct , has been determined by single-crystal X-ray diffraction at room temperature. In this paper a revised model, based on single proton transfer from one molecule of phosphoric acid to the pyridine N atoms opposite to the methyl substituent of the two aminooxo tautomers of 6-methylisocytosine, has been used for the crystal structure analysis of the ionic complex. 6-Methylisocytosine molecules form hemiprotonated centrosymmetric pairs by complementary WC triple hydrogen bonds. Dihydrogen phosphate anions act as bridges between charged WC dimers to generate ribbons via four cation-to anion N–H⋯O hydrogen bonds. Ribbons are then interconnected to form a three-dimensional network by means of a further series of O–H⋯O anion-to-cation hydrogen bonds. [Copyright &y& Elsevier]

Abstract: Reactions in the CuSO4–phen–KVO3–H2O–(KOH) systems under non-hydrothermal conditions yielded seven new compounds: [Cu2(H2O)2(OH)2(phen)2][Cu2(OH)2(phen)2(V4O12)]·6H2O (3), [Cu2(phen)4(V4O12)]·4H2O (4), [Cu2(phen)4(V4O12)]·6H2O (5), [Cu2(phen)4(VO3)4]·10H2O (6), [Cu(phen)3]2V4O12 · phen ·22H2O (7), [Cu(phen)(VO3)2] (9) and [Cu2(phen)4(V4O12)]·4H2O (12). The prepared compounds were characterized by elemental analyses and IR spectra. The characteristic bands in the IR spectra corresponding to the V–O stretching modes enabled the different oxovanadate groups present in the structures to be unequivocally distinguished. Compounds 3, 4, 5, 6, 7 and 12 were characterized by X-ray single crystal diffraction. The structure of compound 3 consists of isolated dinuclear [(phen)(H2O)Cu(μ-OH)2Cu(phen)(H2O)]2+ ions and [(phen)Cu(OH)2Cu(phen)]2+ moieties attached to rings. The structures of compounds 4, 5 and 12 contain [Cu2(phen)4(V4O12)] clusters with different bonding modes of and moieties. The structure of compound 7 is constructed by isolated [Cu(phen)3]2+ and ions as well as molecules of uncoordinated 1,10-phenanthroline and water of crystallization, while a polymeric structure containing chains, to which fragments are attached through Cu–O bonds, was found for 6. [Copyright &y& Elsevier]