New mononuclear mercury(II) complexes of a bifunctionalized ylide containing five-membered chelate ring: Spectral and structural characterization

The reaction of a new bifunctionalized ylide, Ph2PCH2PPh2C(H)C(O)(C6H4Cl) (2) with mercury(II) halides in equimolar ratios using dry methanol as solvent yielded the P, C-chelated complexes, {HgX2[Ph2PCH2PPh2C(H)C(O)(C6H4Cl)]} where X = Cl (3), Br (4), I (5). The structures of complexes 4 and 5 have been characterized crystallographically. Single crystal X-ray analyses reveal the presence of mononuclear complexes containing Hg atom in a distorted tetrahedral environment. Characterization of the obtained compounds was also performed by elemental analysis, IR, 1H, 31P, and 13C NMR. A theoretical study at DFT (B3LYP) level using standard CEP-31G basis set showed that the experimentally determined structure of the complex 5 is about 0.6–15.75 kcal mol−1 more stable than its other bonding modes.