Dichlorcyclopropenon als stabiler Komplexligand. Die Kristallstruktur von [NbOCl3·OC3Cl2]4 / Dichlorocyclopropenone as Stable Complex Ligand. The Crystal Structure of [NbOCl3·OC3Cl2]4

Abstract

The reaction of tetrachlorocyclopropene with NbOCl3 yields NbCl5·OC3Cl2 (1); 1 is also formed by partial hydrolysis of C3Cl3 +NbCl6 - (2), which is prepared from C3Cl4 and NbCl5. [NbOCl3·OC3Cl2]4 (3) was obtained by hydrolysis of 1 in form of pale-yellow, moisture sensitive, non-explosive crystals, and characterized by its IR spectrum and an X-ray crystal structure determination (1871 independent observed reflexions, R = 0.048). Crystal data: space group P1̄. Z = 2. a = 993.7(4), b = 1090.5(5). c = 1097.4(3) pm, α = 69.51(3), β = 70.47(3), γ = 66.51(4)° (at -17 °C). 3 consists of centrosymmetrical tetramers; the four Nb atoms form a square and are linked via almost linear oxo groups with alternating short and long NbO bonds with mean bond lengths of 175 and 208 pm. In trans position of each of the short NbO bonds a dichlorocyclopropenone molecule is attached via its oxygen atom with an NbO distance of 223 pm.