Synthesis and characterization of two novel pyridine-containing framework gallium ethylenediphosphonates.

Two novel gallium diphosphonates, (C5H5N)Ga3F(O3PC2H4PO3)(2) (I) (triclinic, P-1. a = 8.2880(12)angstrom, b = 11.7197(16)angstrom, c = 11.7601(17)angstrom, alpha = 71.589(3)degrees, beta = 70.577(3)degrees, y = 77.313(3)degrees, V= 1013.7(2)angstrom(3), Z = 2, R-1 = 0.0352, wR(2) = 0.0980) and (C5H5NH)(2)[Ga4F2(O3PC2H4PO3)(3)] (II) (triclinic, P-I, a 8.670(4)angstrom b = 9.742(3)angstrom, c = 10.406(2)angstrom, alpha = 81.44(3)degrees, beta = 65.83(5)degrees, y = 67.16(3)degrees, V = 739.0(4)angstrom(3), Z = 2, R-1 = 0.0600, wR(2) 0.1495) have been synthesised by solvothermal methods in the presence of pyridine and their structures determined using single-crystal X-ray diffraction data. Both compounds I and II are composed of various Ga-centered polyhedra and ethylenediphosphonate groups that link toggether to form framework materials with one- and two-dimensional channel systems, respectively. The two structures are formed in the presence of structure-directing pyridine molecules that are directly bound to some of the Ga atoms in I, and are protonated as pyridiniurn cations in II. Compounds I has a charge-neutral framework, while compound II has an anionic framework. Both materials provide rare examples of organically structure-directed framework metal diphosphonate materials. (c) 2006 Elsevier Inc. All rights reserved.