The non-coordinating anion 1,1,3,3-tetracyano-2-propoxy-propenide as an anion-pi donor in cis-diaquabis(2,2 '-dipyridylamine)zinc and its cadmium analog: Luminescence properties, Hirshfeld analysis and central-atom induced polymorphism

Metals in Catalysis, Biomimetics & Inorganic Material

Synthesis, structure and luminescence properties of zinc and cadmium linear-chain compounds with anionic monoalkoxy-tetracyanopropenes bridged by 4,4 '-bipyridines

The synthesis, characterization and 3D structure determination of Zinc and Cadmium compounds are reported, containing the non-chelating bidentate ligand 4,4'-bipyridine and the anions 1,1,3,3-tetracyano-2-propoxy-propenide (tcnopr) or 1,1,3,3-tetracyano-2-ethoxy-propenide (tcnoet). The structures consist of linear chains (1D) built from metal ions and 4,4'-bipyridine, where the octahedral coordination around the metals is completed by two trans anions tcnoet (or tcnopr), and two trans-oriented water molecules. Weak interchain interactions are present, based on hydrogen bonds between the water ligands (both hydrogens are involved) and two CN groups of two nearby other chains. Metal-ligand distances appear as uneventful. For the same anion, the Zn and Cd compounds are isomorphous. Possible decomposition of the compounds has been investigated in the temperature range 30-800 degrees C in a static air atmosphere. Thermal analysis studies (TG, DTG, DTA) show that the axial water ligands for all three compounds are gradually lost upon heating above 60 degrees C to about 170 degrees C. Luminescence properties, recorded as powders, are reported as well, and these appear as strong for the Cd compound I, when irradiated at 390 nm, extremely weak for the Cd compound II, when irradiated at wavelengths from 300-400 nm, and moderately weak for the Zn compound III when irradiated at 385 nm. (C) 2019 The Author(s). Published by Elsevier Ltd.Metals in Catalysis, Biomimetics & Inorganic Material

1,1'-Diethyl-4,4'-bipyridine-1,1'-diium bis(1,1,3,3-tetracyano-2- ethoxypropenide) : multiple C-H⋯N hydrogen bonds form a complex sheet structure

The authors acknowledge the Algerian ATRST (Agence The´matique de Recherche en Sciences et Technologie; PNR project) and the Ministry of Higher Education of Malaysia (grant No. UM.C/HIR-MOHE/SC/03) for financial support.In the title salt, C14H18N22+·2C9H5N4O−, the 1,1′-diethyl-4,4′-bipyridine-1,1′-diium dication lies across a centre of inversion in the space group P21/c. In the 1,1,3,3-tetracyano-2-ethoxypropenide anion, the two independent –C(CN)2 units are rotated, in conrotatory fashion, out of the plane of the central propenide unit, making dihedral angles with the central unit of 16.0 (2) and 23.0 (2)°. The ionic components are linked by C—H⋯N hydrogen bonds to form a complex sheet structure, within which each cation acts as a sixfold donor of hydrogen bonds and each anion acts as a threefold acceptor of hydrogen bonds.Publisher PDFPeer reviewe