Low-dimensional compounds containing cyanido groups. XXIV. Crystal structure, spectroscopic and thermal properties of two Cu(II) tetracyanidoplatinate complexes with tetradentate N-donor ligands

摘要

Violet crystals of [Cu_2(teta)_2Pt(CN)_4]_2[Pt(CN)_4]_2 (1, teta = N,N'-bis(2-aminoethyl)-1,2-diaminoethane; triethylenetetramine) and {[Cu_3(bapen)_3Pt(CN)4][Pt(CN)_4]_2?13H_2O}_n (2, bapen = N,N0-bis(3-aminopropyl)- 1,2-diaminoethane) were crystallized from the water-methanol or aqueous solutions containing Cu(II) salt, teta or bapen ligand and K_2[Pt(CN)_4]. Both compounds were characterized using elemental analysis, IR and UV-Vis spectroscopy, thermal and X-ray crystal structure analysis. Two m(C≡N) absorption bands in the IR spectra of the complexes imply non-equivalency of cyanido groups meaning the presence of both, terminal and bridging ones and together with the results of elemental analysis indicate simple chain-like structure. Thermal decompositions of the prepared complexes are few-step processes which comprise liberation of crystal water (only for 2), decay of N-donor ligands L and release of cyanido groups. Finally, an X-ray crystal structure analysis has shown their complicated crystal structures. On one hand, complex 1 is of ionic character and is formed from a couple of trinuclear [Cu(teta)-Pt(CN)_(4-)Cu(teta)]~(2+) complex cations and a couple of discrete [Pt(CN)_4]_(2﹣) anions. On the other hand, complex 2 is of polymeric character and is formed by 1D chains of {[Cu_3(bapen)_3Pt(CN)_4]~(4+)}~n composition, 2n single [Pt(CN)_4]~(2﹣) anions and 13n molecules of crystal water.