Synthesis, Crystal Structure, and Properties of the First Organomercury Dimer Derived from PMP

The organomercury dimer [Hg2(PMP)Cl2]2·DMF (1) (PMP = 1-phenyl-3-methyl-2-pyrazolin-5-one) was prepared by the reaction of mercury chloride with PMP and characterized by elemental analysis, IR spectroscopy, TG, and single-crystal X-ray diffraction analysis. The title compound crystallizes in the triclinic space group P, with a = 7.4298(6), b = 9.0313(8), c = 12.4145(13) A, V = 760.50(12) A3, Z = 1. Each mercury(II) atom is tricoordinated to one chlorine atom, one carbon atom of the pyrazole ring from one PMP, and one oxygen atom from another PMP. The coordination arrangement around the mercury atom is T-shaped. This is the first structural report on an organomercury derivative of PMP. The distance between the two HgII ions is 3.2735(8) A, which indicates the presence of weak Hg···Hg interactions. Meanwhile, 1 can be connected by intermolecular C–H···Cl hydrogen bonding and weak Hg···O/Cl/N interactions to form a three dimensional network. The thermal stability and antibacterial activity of 1 were studied. The binding of 1 with calf thymus DNA was investigated by absorption spectroscopy and viscometry.