Crystal structure of μ-cyanido-1:2κ 2 N : C -dicyanido-1κ C ,2κ C -bis(quinolin-8-amine-1κ 2 N , N ′)-2-silver(I)-1-silver(II): rare occurrence of a mixed-valence Ag I,II compound

• Published in: Acta crystallographica. Section E, Crystallographic communications Vol. 71; no. 6; pp. 698 - 701
• Main Authors: Setifi, Zouaoui, Bernès, Sylvain, Pérez, Olivier, Setifi, Fatima, Rouag, Djamil-Azzeddine
• Format: Journal Article
• Language: English
• Published: 01.06.2015
• ISSN: 2056-9890; 2056-9890
• DOI: 10.1107/S2056989015009664

The title dinuclear complex, [Ag 2 (CN) 3 (C 9 H 8 N 2 ) 2 ], may be considered as an Ag II compound with the corresponding metal site coordinated by two bidentate quinolin-8-amine molecules, one cyanide group and one dicyanidoargentate(I) anion, [Ag(CN) 2 ] − . Since this latter ligand contains an Ag I atom, the complex should be a class 1 or class 2 mixed-valence compound, according to the Robin–Day classification. The Ag II atom is six-coordinated in a highly distorted octahedral geometry, while the Ag I atom displays the expected linear geometry. In the crystal, the amino groups of the quinolin-8-amine ligands form N—H...N hydrogen bonds with the N atoms of the non-bridging cyanide ligands, forming a two-dimensional network parallel to (102). The terminal cyanide ligands are not engaged in polymeric bonds and the title compound is an authentic molecular complex. The title molecule is thus a rare example of a stable Ag I,II complex, and the first mixed-valence Ag I,II molecular complex characterized by X-ray diffraction.