Structural Investigation of Di-μ-chloro-bis[saccharinatopyridinemercury(II)] by X-ray Diffraction and FT IR Spectroscopy

The solid state structure of [C₁₂H₉ClHgN₂O₃S]₂ was determined and the appropriate assignment of the CO and SO₂ stretching vibrations in the FT IR spectrum was made. Two monomeric chlorosaccharinatopyridinemercury(II) moieties are joined together forming a di-μ-chloro bridged dimmer by an inversion centre operation. The mercury atom is coordinated with two bridging chlorine and the pyridine and saccharinato nitrogen atoms in the shape of a heavily distorted tetrahedron. There is a significant difference between Hg1-Cl1 [2.533(2) Å] and Hg1-Cl1ⁱ [2.715(2) Å] distances as well as between Hg1-N11 [2.106(7) Å] and Hg1-N21 [2.209(7) Å] bond lengths. The valence bond angles at the metal atom deviate significantly from the standard tetrahedral value, ranging from 86.23(7)° for Cl1-Hg1-Cl1ⁱ to 131.5(3)° for N11-Hg1-N21. Discrete molecules are linked together by weak intermolecular C-H...O attractions at distances less than 3.5 Å.