Structure and stability of water soluble (NH4)8[Ti4(C6H4O7)4(O2)4]•8H2O

Ammonium citratoperoxotitanate(IV), (NH4)(8)[Ti-4(C6H4O7)(4)(O-2)(4)]. 8H(2)O, was isolated in the solid form. Its crystal structure was solved and refined using single-crystal X-ray data. The compound crystallizes in a monoclinic cell with a = 10.237(2) Angstrom, b = 17.537(4) Angstrom, c = 14.713(3) Angstrom, beta = 100.35(1)degrees (Z = 2, fw = 1360.40, rho (calc) = 1.74 g/cm(3)) and space group P2(1)/n (No. 14). The determined structure of the titanium complex agrees well with the Raman and NMR spectroscopic data. We speculate that tight coordination of titanium in the complex molecule is responsible for the high stability of this compound against hydrolysis.