SYNTHESIS, CRYSTAL-STRUCTURES, AND COORDINATION INTERCALATION BEHAVIOR OF 2 COPPER PHOSPHONATES

Two copper phosphonates, Cu(O3PCH3).H2O and Cu(O3PC6H5).H2O, have been synthesized and their structures determined. Cu(O3PCH3).H2O is monoclinic: space group P2(1)/c, a = 8.495 (4) angstrom, b = 7.580 (4) angstrom, c = 7.289 (4) angstrom, beta = 90.08 (4)-degrees, Z = 4, V = 469.4 (7) angstrom3. Refinement with 683 observed reflections for which I greater-than-or-equal-to 3-sigma(I) gave R = 0.030 and R(w) = 0.041. The structure is layered as formed by unusual 5-coordinate distorted tetragonal pyramidal copper atoms. One oxygen of each phosphonate bonds to two copper atoms forming a chain, while the other two phosphonate oxygens bond to two copper atoms in an adjacent chain. The base of the pyramid thus consists of three phosphonate oxygens and the coordinated water molecule. All hydrogen bonds are of the intralayer type, so only van der Waals forces exist between adjacent layers. Amines are coordinatively intercalated with layer expansion. Cu(O3PC6H5).H2O is orthorhombic: space group Pbca, a = 7.5547 (4) angstrom, b = 7.4478 (6) angstrom, c = 27.982 (1) angstrom, Z = 8, V = 1574.4 (2) angstrom3. Refinement using 952 reflections for which I greater-than-or-equal-to 3-sigma(I) gave R = 0.037 and R(w) = 0.043. The coordination about the copper atoms and the layer structure are identical to those of the methylphosphonate compound. However, the phenyl rings in the interlamellar space are oriented at a 98-degrees angle to each other in adjacent rows. These structures are compared to those of other layered divalent phosphonates and copper phosphites.