Coordination chemistry of polynitriles, I. Syntheses and crystal structures of [Ag(PCC)(DMF)], [Ni(DMF)_6](PCC)_2 and [Co(DMF) _6](PCC)_2 (PCC = [C_5(CN)_5] ~-, DMF = N,N-dimethylformamide)

摘要

Recrystallization of silver pentacyanocyclopentadienide Ag[C _5(CN)_5] from N,N-dimethylformamide (DMF) gives the polymeric 1: 1 complex [Ag{C_5(CN)_5}(DMF)] (1). The Ag~+ cation is coordinated by three N atoms of three different [C _5(CN)_5]~- anions and two O atoms of two DMF molecules. Each [C_5(CN)_5]~- is coordinated via three neighboring CN groups to three different Ag~+ ions, while each DMF molecule bridges two Ag~+ ions via its O atom. Treatment of NiCl_2·6H_2O, CoCl_2·6H_2O or ZnCl_2 with Ag[C_5(CN)_5] in DMF gives the DMF complexes [M(DMF)_6][C_5(CN)_5]_2 (M=Ni, 2; Co, 3; Zn, 4). The complexes 2 and 3 were characterized by X-ray diffraction and show octahedral [M(DMF)_6]~(2+) cations with O-coordinated DMF molecules. The [C_5(CN)_5]~- anions show ideal pentagonal symmetry.