title: Coordination abilities of polycyano anions in the solid state: coordination geometries and d-d transition energies of mixed-ligand solvatochromic copper(ii) complexes with B(CN)4, C(CN)3, and N(CN)2anions.
abstract: B(CN)4-, C(CN)3-, and N(CN)2-are highly versatile polycyano anions that produce various functional compounds. To investigate the coordination abilities of these anions in the solid state quantitatively, we synthesized mixed-ligand Cu(ii) complexes: [Cu(R-acac)(tmen)X] (X = polycyano anion, R-acac = acetylacetonate or butyl-acetylacetonate, tmen = tetramethylethylenediamine). The coordination abilities of the anions, increasing in the order B(CN)4-< C(CN)3-< N(CN)2-, result in a decrease in the d-d transition energies of the complexes and the shortening of the axial coordination distance. The influence of crystal packing on the coordination geometries and d-d transition energies of the complexes was also demonstrated. The donor numbers of the anions were determined from the d-d transition energies in solution.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kobe University, Kobe, Hyogo 657-8501, Japan. tmochida@platinum.kobe-u.ac.jp.
authors.forename: Xue
authors.initials: X
authors.lastname: Lan
authors.forename: Takumi
authors.initials: T
authors.lastname: Tominaga
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Mochida