Na-0.10(VO)(0.45)LaTiO4.nH(2)O (n congruent to 0.6) has been synthesized by an ion exchange reaction between the single-layered perovskite, NaLaTiO4, and aqueous VOSO4. This low temperature phase retains the structure of the parent with a slight contraction of its tetragonal unit cell. Rietveld refinement of X-ray powder diffraction data indicate that the vanadyl units are disordered within the perovskite layers. Infrared spectroscopy, electron spin resonance and magnetic susceptibility are consistent with the presence of isolated vanadyl units. Susceptibility data show Curie-Weiss behavior above 140 K. (C) 2004 Elsevier Ltd. All rights reserved.