Anion influence in the structural diversity of cadmium coordination polymers constructed from a pyridine based Schiff base ligand

作者：Khandar Ali Akbar^*; Afkhami Farhad Akbari; Hosseini Yazdi Seyed Abolfazl; White Jonathan M; Kassel Scott; Dougherty William G; Lipkowski Janusz; Van Derveer Donald; Giester Gerald; Costantino Ferdinando

来源：Inorganica Chimica Acta, 2015, 427: 87-96.

DOI：10.1016/j.ica.2014.11.028

• Cadmium(II)
• 2-Pyridinecarbaldehyde isonicotinoyl hydrazone
• Coordination polymer
• Crystal structure
• Anion effect

A series of seven coordination polymers based on Cd and potentially tetradentate pyridine based Schiff base ligand with different anions (CH3COO-, NO2-, Cl-, I-, N-3(-), SCN-), [Cd(L)(CH3COO)(OH2)](n) (1),{[Cd-2 (L)(2)(NO2)(2)(CH3OH)(2)]center dot CH3OH}(n) (2), {[Cd-2(L)(2)Cl-2(CH3OH)(2)]center dot CH3OH}(n) (3), [Cd(HL)I-2](n) (4), [Cd-3(L)(2)(N-3)(4)](n) (5), [Cd(L)(SCN)(OH2)](n) (6) and [Cd(HL)(SCN)(2)](n) (7) {HL = 2-pyridinecarbaldehyde isonicotinoyl hydrazone (HPCIH)} in order to rationalize the effect of the anion, have been synthesized and characterized by elemental analyses, FT-IR spectroscopy, single crystal X-ray data diffraction, etc. The results show the influence of the counter-ions on the coordination mode of the cadmium ion that is capable of forming compounds with five-, six-and seven-coordination numbers. The ligand acts as a negatively charged tetradentate N3O-donor ligand and coordinates to the cadmium center in the enolic form (=N-N=C-O) in 1-3 and 5-6 while in compounds 4 and 7 coordinates as N-3- and N3O-donor neutral ligand in keto form (=N-NH-C=O), respectively. Cadmium centers in 1-4 and 6, bridging by the HPCIH ligand cause to form one-dimensional coordination polymers and the anions act as terminal ligands. In compounds 5 and 7, the N-3- and SCN- also act as bridging ligands to the metal centers, and form 3D and 2D metal-organic polymers respectively.

• 出版日期2015-3-1
• 单位Perugia