Synthesis, Characterization, and DFT Investigation of a Zinc(II)–Silver(I) Bimetallic Complex, [Zn(Dmen)2{Ag(CN)2}2][Zn(Dmen)2(H2O)2]{Ag(CN)2}2 (Dmen = N,N′-Dimethylethylenediamine)

A cyanido bridged Zn(II)-Ag(I) bimetallic complex ( I ) has been prepared and characterized by IR spectroscopy, thermal analysis, X-ray crystallography (CIF file CCDC no. 884016) and DFT calculations. Thermal analysis shows that the composition of the compound is consistent with the proposed stoichiometry, i.e., [Zn(diamine) 2 {Ag(CN) 2 } 2 ] · H 2 O. The crystal structure of complex I consists of two independent molecules; a trinuclear molecule, [Zn(Dmen) 2 {Ag(CN) 2 } 2 ] and an ionic species, [Zn(Dmen) 2 -(H 2 O) 2 ]{Ag(CN) 2 } 2 ; the overall formula being [Zn(Dmen) 2 {Ag(CN) 2 } 2 ][Zn(Dmen) 2 (H 2 O) 2 ]{Ag(CN) 2 } 2 ( I ) (Dmen = N,N ′-dimethylethylenediamine). The structures of I and two of its analogues, [Zn(Dmen) 2 {Ag(CN) 2 } 2 ] 2 · 2H 2 O ( II ) and {[Zn(Dmen) 2 {Ag(CN) 2 }][Ag(CN) 2 ]} 2 · 2H 2 O ( III ) were predicted by DFT calculations. The DFT results reveal that the structure I is more stable in comparison to the calculated structures, II and III . The X-ray structure of I shows that the complex is also stabilized by the argentophilic interactions. The Ag···Ag interaction energy calculated at the MP2 level of theory is –4.02 kcal mol –1 .