Syntheses, Crystal Structures, and Properties of Five New Transition Metal Molybdenum(VI) Selenites and Tellurites

Abstract

Five new transition metal molybdenum(VI) selenites or tellurites, namely, TM(MoO(3))(SeO(3))(H(2)O) (TM = Mn, Co), Fe(2)(Mo(2)O(7))(SeO(3))(2)(H(2)O), Cu(2)(MoO(4))(SeO(3)), and Ni(3)(MoO(4))(TeO(3))(2), have been prepared and structurally characterized. They belong to five different types of structures. Mn(MoO(3))(SeO(3))(H(2)O) and Ni(3)(MoO(4))(TeO(3))(2) are non-centrosymmetric and crystallize in the orthorhombic space groups Pmc2(1) and P2(1)2(1)2(1), respectively, whereas Co(MoO(3))(SeO(3))(H(2)O), Fe(2)(Mo(2)O(7))(SeO(3))(2)(H(2)O), and Cu(2)(MoO(4))(SeO(3)) are centrosymmetric and crystallize in P1, C2/c, P2(1)/c, respectively. The Mo(6+) cations in Mn(MoO(3))(SeO(3))(H(2)O), Co(MoO(3))(SeO(3))(H(2)O), and Fe(2)(Mo(2)O(7))(SeO(3))(2)(H(2)O) are in severely distorted octahedral geometry whereas those in Cu(2)(MoO(4))(SeO(3)) and Ni(3)(MoO(4))(TeO(3))(2) are in a slightly distorted tetrahedral geometry. Second-Harmonic Generation (SHG) measurements revealed that (MoO(3))(SeO(3))(H(2)O) displays a moderate SHG signal of about 3 x KH(2)PO(4) (KDP) whereas the SHG response of Ni(3)(MoO(4))(TeO(3))(2) is much weaker than that of KDP.