Synthesis, Crystal Structure and Properties of [Gd(C 6 NO 2 H 5 ) 3 (H 2 O) 2 ] n (1.5 n ZnCl 4 )· n H 2 O with Unprecedented Poly-Cationic Chains

A new heterometallic 4f-3d inorganic-organic metal-nicotinic acid complex [Gd(C 6 NO 2 H 5 ) 3 (H 2 O) 2 ] n (1.5 nZnCl 4 ) nH 2 O, (1), has been synthesised via hydrothermal reaction and structurally characterised. Complex 1 crystallises in the space group P2 1 / c of the monoclinic system with four formula units in a cell: a = 9.524(2), b = 20.888(4), c = 16.078(3) Å β = 104.745(2)°, V= 3093.2(9) Å 3 , C 18 H 21 Cl 6 GdN 3 O 9 Zn 1.50 , M r =891.38 g/mol, D c = 1.914 g/cm 3 , S = 0.997, μ(MoKα) = 3.844 mm 1 , F(000) = 1732, R = 0.0493 and wR = 0.1350. Complex 1 is characteristic of a one-dimensional polycationic chain-like structure. Photoluminescent investigation shows that the title complex displays strong emission in the blue region, which is attributed to the intraligand π–π * transition of nicotinic ligands. Optical absorption spectra of 1 reveal the presence of a wide optical bandgap of 3.73 eV.