Abstract
Chemical preparation, calorimetric studies, crystal structure, and IR absorption spectra are given for a new organic cyclohexaphosphate. The aza-3 pentanediyl-1,5 dihydrate, [NH3-(CH2)(2)-NH2-(CH2)(2)-NH3]2P6O18 . 2H2O is triclinic P (1) over bar with unit cell dimensions, a = 8.709(2), b = 9.729(2), c = 9.145(2) Angstrom, alpha 99.11(2)degrees, beta = 110.70(2)degrees, gamma 67.19(2)degrees, and Z = 1, V = 667.9(6). Angstrom(3), rho(m) = 1.72 g.cm(-3), mu = 0.268 mm(-1). The refinement of data, collected at room temperature, leads to a final R = 0.035 for 3844 independent reflections. The P6O18 ring anion is centrosymmetric and significantly distorted with P-P-P angles varying from 93.6 degrees to 134.8 degrees as commonly observed for such rings with (1) over bar internal symmetry. A three-dimensional network of strong hydrogen bonds interconnects the structural arrangement. Of the eight hydrogen atoms in the organic group, seven are connected to the external oxygen atoms of four phosphoric rings and form a complex anion of formula [C4N3H16(P6O18)4](-21); the remaining one establishes a hydrogen bond with a water molecule which links, with the help of its proper hydrogen atoms, successive complex anions. The hydrogen bonding geometries are discussed. (C) 1995 Academic Press, Inc.