Five new phenyl- and benzylphosphonates of tetravalent vanadium, Ca(VO)(O3PPh)2·2H2O(1), Cd(VO)(O3PPh)2·2H2O(2), Ba(VO)(O3PCH2Ph)2·2H2O(3), Sr(VO)3(O3PPh)4·5H2O(4) and Ba[V4O4(OH)2(O3PPh)4]·5H2O(5), were synthesized under hydrothermal conditions and structurally characterized by single crystal and powder X-ray diffraction, CHN analyses, infrared spectroscopic, magnetic and thermal studies. They have layered structures, wherein the vanadium and alkaline earth or cadmium metal ions are approximately confined to a crystallographic plane and bonded to oxygen atoms of phenyl/benzylphoshonate moieties and water of crystallization. The structures of compounds 1–3 are of new type, whereas the compounds 4 and 5 have known types of structures. Their magnetic susceptibilities in the 20–300 K regions were found to vary with temperature, according to the Curie-Weiss law. The compounds 1 and 2 showed phase matching second-harmonic-generation responses. © 2018 Elsevier Inc.