AMMONIUM DI-MU-OXALATOTITANATE(III) DIHYDRATE - AN 8-COORDINATE, POLYMERIC TITANIUM(III) COMPLEX

The preparation, magnetic and spectral properties and crystal structure of ammonium di-mu-oxalatotitanate(III) dihydrate are described. NH4[Ti(C2O4)2].2H2O, M(r) = 278.01, hexagonal, P6(2)22, a = 8.935(3) c = 10.878(4) angstrom, V = 752.1(7) angstrom3, Z = 3; R = 0.045 for 426 absorption-corrected independent reflections and 48 parameters. The crystals are isomorphous with those of ammonium di-mu-oxalatoindate(III) dihydrate. The titanium atoms are coordinated by eight oxalate oxygen atoms in a square-antiprismatic arrangement, and bridging oxalate groups link the coordination polyhedra to form a right-handed spiral structure about 6(2) crystal axes.