[Hg(pyridine)(2)][Cr2O7], a compound used for a quick assay method to quantify soluble Hg-II ions

The title compound, bis(pyridine-N)mercury(II) dichromate(VI), [Hg(C5H5N)(2 )][Cr2O7], is the first structurally determined representative of metal dic hromates with additional pyridine ligands of general formula [M(py)(n)](m)C r2O7 (py = pyridine) and can be used for a quick assay method to quantify H g-II ions in solution. Two distinct Hg atoms, both located on special posit ions with symmetry 2 and (1) over bar, respectively, are coordinated octahe drally by two axial N atoms of pyridine rings at short distances (d) over b ar (Hg-N) = 2.101 Angstrom and four equatorial O atoms of dichromate groups at longer distances (d) over bar (Hg-O) = 2.620 Angstrom. The dichromate g roup has a skew conformation with a bridging angle of 138.62 (17)degrees.