Bis(imidazol-2-yl)phosphinic acid hemihydrate, [(C3H3N2)(C3H4N2)PO2].(1/2)H2O
The title compound was obtained as the major product of our handling of the literature preparation of tris(imidazol-2-yl)phosphine. The compound was characterized by 1H NMR, mass and vibrational spectroscopy. The structure was determined by single crystal X-ray diffraction. Crystals were triclinic, [Formula: see text], a = 7.677(1), b = 12.658(2), c = 10.072(2) Å, α = 91.18(1),β = 114.44(1),γ = 99.49(1)°, Z = 4. Intensities were measured on a Syntex P21 diffractometer with MoKα radiation and 3088 reflections were used to determine the structure. R = 0.0698, Rw = 0.0534. The phosphinic acid exists in the solid as the zwitterionic form and bond lengths and angles are normal. Keywords: tris(imidazol-2-yl)phosphine, X-ray structure, bis(imidazol-2-yl)phosphinic acid hemihydrate.