COMPLEXES OF MERCURY(II) WITH TETRAETHYL 2,2'-BIPYRIDYL-4,4'-DIPHOSPHONATE

Complexes [Hg(bipyP(2))Br-2] (2), [Hg(bipyP(2))BrCl] (3), and [Hg(bipy P(2))Cl-2] (4), where bipyP(2) is tetraethyl 2,2'-bipyridyl-4,4'-dipho sphonate (1), were prepared and their crystal structures were determin ed. Coordination of the phosphonate group was only found in 4. In this compound, the coordination sphere of Hg(II) contains two Cl atoms, tw o N atoms from the bipyridine chelate and O atom from phosphonate grou p and thus, the coordination number is five. The presence of Br atoms in the coordination sphere of complexes 2 and 3 results in the formati on of tetrahedral environment (coordination number four) without any i nteraction with phosphonate. The coordination of the phosphonate group in 4 was also confirmed by IR spectroscopy.