Publication Date:
2014-11-18
Description:
The crystal structures of a series of pyridine coordination polymers [ M II Cl 2 (C 5 H 5 N) x ] n ( M = Ni, Cu), prepared via thermal decomposition are reported. [NiCl 2 (C 5 H 5 N) 4 ] ( 1 ) decomposes stepwise via [NiCl 2 (C 5 H 5 N) 2 ] n ( 2 ), [NiCl 2 (C 5 H 5 N)] n ( 3 ), and [NiCl 2 (C 5 H 5 N) 2/3 ] n ( 4 ), to NiCl 2 with increasing temperature. The thermal decomposition of [CuCl 2 (C 5 H 5 N) 2 ] n ( 5 ), progresses via two polymorphs of [CuCl 2 (C 5 H 5 N)] n ( 6a and 6b ), and [CuCl 2 (C 5 H 5 N) 2/3 ] n ( 7 ), to CuCl 2 . The compounds 3 , 4 , and 7 were prepared as pure phases. All crystal structures were determined by X-ray powder diffraction. Notably, the crystal structures of the polymorphs 6a and 6b were determined from powder diffraction data of a mixture of both phases. Crystal structures of [ M II Cl 2 (C 5 H 5 N) x ] n with the same x , but different metal atoms (Ni, Cu) are homeotypic, compounds 4 and 7 are isotypic. Compounds with x = 1 ( 3 , 6a , 6b ) are composed of polymeric octahedra double chains 1 ∞ [ M Cl 3/3 Cl 2/2 (C 5 H 5 N)] and in case of x = 2/3 ( 4 , 7 ) of triple chains. The Jahn-Teller distortion in the copper compounds was observable with the pair distribution function (PDF) analysis.
Print ISSN:
0044-2313
Electronic ISSN:
1521-3749
Topics:
Chemistry and Pharmacology
Permalink
