Synthesis and characterization of bis(η2-alkyne)dihalogeno-mercury(II) compounds: crystal structure of [NBu4]2-[{cis-Pt(C6F5)2(CCSiMe3)2}HgBr2]·CH2Cl2

TLDR: In this article, a 1:1 molar ratio was obtained for the bis(η2-alkyne)mercury(II) compounds [NBu4]2[{cis-Pt(C6F5)2(CCSiMe3)2}HgBr2]·CH2Cl2 has been determined by X-ray diffraction methods.

Abstract: The reactions of [NBu4]2[cis-Pt(C6F5)2(CCR)2](R = But or SiMe3) with HgX2(X = Cl, Br or I) in a 1:1 molar ratio afforded the simple monomeric bis(η2-alkyne)mercury(II) compounds [NBu4]2[{cis-Pt(C6F5)2(CCR)2}HgX2](R = But or SiMe3; X = Cl, Br or I) in which both alkyne units are co-ordinated η2 side-on to the precursor mercury(II) halides. Similar treatment of [NBu4]2[Pt(CCR)4]·2H2O (R = But or SiMe3) with HgX2 in a 1:2 molar ratio gave the corresponding trinuclear 1:2 adducts. All the complexes have been characterized by analytical and spectroscopic data and, in addition, the molecular structure of [NBu4]2[{cis-Pt(C6F5)2(CCSiMe3)2}HgBr2]·CH2Cl2 has been determined by X-ray diffraction methods. The structure of the anion shows that the HgBr2 unit is attached to the dianionic fragment [Pt(C6F5)2(CCSiMe3)2]2– only through η2 side-on co-ordination of the two (trimethylsilyl)ethynyl ligands. The platinum–mercury distance is 3.627(1.5)A.