Synthesis of novel mercury(I) complexes containing a linear chain Co–Hg–Hg–Co. X-Ray crystal structure of the complex [{Co[N(CH2CH2PPh2)3]}2(µ-Hg2)]·thf

Abstract

Reduction of the cobalt(II) complexes [CoLCl]BPh₄[L = N(CH₂CH₂PPh₂)₃(dppea) or P(CH₂CH₂PPh₂)₃(dppep)] with sodium amalgam gives tetrametallic complexes of formula [(CoL)₂(µ-Hg₂)]. The structure of [{Co(dppea)}₂(µ-Hg₂)]·thf was determined from three-dimensional X-ray data collected by the counter method. The crystals are triclinic, space group P, with a= 25.691(9), b= 13.387(5), c= 13.471(4)Å, α= 119.56(8), β= 97.51(8), γ= 87.25(7)°, and Z= 2. Full-matrix least-squares refinement converged at the conventional R factor of 0.067 for 2 687 observed reflections. The structure consists of dimeric units of [{Co(dppea)}₂(µ-Hg₂)] where the Hg₂²⁺ ion linearly bridges two Co(dppea) fragments. The dppea derivative reacts with carbon monoxide or carbon dioxide, at room temperature and atmospheric pressure, with formation of the carbonyl complex [Co(dppea)(CO)]BPh₄.