Synthesis, spectra and crystal structures of zwitterionic mercury(II) complexes formed by the ligand, [Ph2PCH2PPh2CH2C(O)Ph]+

The reactions of phosphonium salt, [PPh2CH2PPh2CH2C(O)Ph]Br with Hg(II) halides in methanol formed the zwitterionic products with the composition [HgCl2(Br)(PPh2CH2PPh2CH2C(O)Ph)] (2), [HgBr3(PPh2CH2PPh2CH2C(O)Ph)] (3), [HgBr2(I)(PPh2CH2PPh2CH2C(O)Ph)] (4). A product of composition, [HgCl3(PPh2CH2PPh2CH2C(O)Ph)] (5) was obtained when the ylide, Ph2PCH2PPh2CHC(O)Ph was treated with HgCl2 in CH2Cl2 and crystallized under aerobic conditions. The complexes were characterized by elemental analysis, IR, 1H, 31P NMR spectra and also by X-ray crystallography. The absence of significant coordination chemical shifts in the 31P NMR spectra indicates the presence of formal negative charge on mercury. The single crystal X-ray structures confirm the presence of Hg–P bond and also reveal a distorted tetrahedral geometry around the mercury atom in all the structures.

Graphical abstractThe unsymmetrical phosphonium salt (1) reacts with Hg(II) halides to form different zwitterionic complexes as confirmed by single crystal X-ray analysis.Figure optionsDownload full-size imageDownload as PowerPoint slide