An Inorganic Double Helix: Hydrothermal Synthesis, Structure, and Magnetism of Chiral [(CH3)2NH2]K4[V10O10(H2O)2(OH)4(PO4)7]·4H2O
Victoria Soghomonian 1,
Qin Chen 2,
Robert C. Haushalter 3,
Jon Zubieta 2, and
Charles J. O'Connor 4
1 NEC Research Institute, 4 Independence Way, Princeton, NJ 08540, and Department of Chemistry, Syracuse University, Syracuse, NY 13244
2 Department of Chemistry, Syracuse University, Syracuse, NY 13244
3 NEC Research Institute, 4 Independence Way, Princeton, NJ 08540
4 Department of Chemistry, University of New Orleans, New Orleans, LA 70148
Very complicated inorganic solids can be self-assembled from structurally simple precursors as illustrated by the hydrothermal synthesis of the vanadium phosphate, [(CH3)2NH2]K4[V10O10(H2O)2(OH)4(PO4)7]·4H2O, 1, which contains chiral double helices formed from interpenetrating spirals of vanadium oxo pentamers bonded together by P5+. These double helices are in turn intertwined with each other in a manner that generates unusual tunnels and cavities that are filled with (CH3)2NH2+ and K+ cations, respectively. The unit cell contents of dark blue phosphate 1, which crystallizes in the enantiomorphic space group P43 with lattice constants a = 12.130 and c = 30.555 angstroms, are chiral; only one enantiomorph is present in a given crystal. Magnetization measurements show that 1 is paramagnetic with ten unpaired electrons per formula unit at higher temperatures and that antiferromagnetic interactions develop at lower temperatures.
Submitted on November 20, 1992
Accepted on January 26, 1993
