A new one-dimensional strontium vanadium tellurite, Sr₇V₄Te₁₂O₄₁

Abstract

Vanadium tellurites display a rich structural chemistry with interesting physical properties, such as second harmonic generation (SHG). Tellurites, i.e. Te(4+)Ox, are often observed in unusual structures and form various structural motifs, including isolated clusters, chains, layers, and three-dimensional networks. Similarly, vanadates, i.e. V(5+)Ox, show rich structural features, such as VO4 tetrahedra, VO5 square pyramids or trigonal bipyramids, and VO6 octahedra. Strontium vanadium tellurite, Sr7V4Te12O41, was obtained from the melt of the solid-state reaction of SrTeO4 and VO2 in a sealed quartz tube as it cooled from 973 K. The crystal structure exhibits a one-dimensional latticework along the a axis comprised of paired Sr3Te3Ox units, namely Sr6Te6O2x+1, with corner-shared TeO4 polyhedra - and specifically the Te lone-pair electrons - facing outward in the bc plane. The Sr6Te6O2x+1 latticework is helical and is layered in the b-axis direction against sheets of corner-shared VO4 tetrahedra, and is linked in the c-axis direction via individual corner-shared SrO8 square prisms.

Syntheses, Crystal Structure, and Second Harmonic Generation Response of Four Novel Noncentrosymmetric Tellurites of Quaternary A/M/Te/O (A = Ba, Sr, Ca; M = V, Nb, Ta) System: BaTa4Te3O17, BaNb4Te3O17, SrTa4Te3O17, and CaV2TeO8

“…There are 19 selenites and tellurites of vanadium­(V) of the quaternary A/V/X/O (A = Ba, Sr, Ca, Cd, Pb; X = Se, Te) system reported. − They are BaV 2 SeO 8 , Ba 3 V 2 Se 4 O 16 , Ba 2.5 V 3 Se 4 O 18 ·H 2 O, Sr 2 V 2 Se 3 O 13 , Sr 4 V 2 Se 6 O 21 , Ca 2 V 2 Se 3 O 13 ·2H 2 O, Cd 6 V 2 Se 5 O 21 , CdV 4 Se 3 O 17 ·H 2 O, Pb 2 V 2 Se 2 O 11 , Pb 4 V 2 Se 6 O 21 , Pb 4 V 6 Se 3 O 25 ·H 2 O, β-Pb 4 V 6 Se 3 O 25 ·H 2 O, BaV 2 TeO 8 , Ba 2 V 2 Te 2 O 11 , Ba 2 VTe 4 O 12 (OH), SrV 2 TeO 8 , Sr 7 V 4 Te 12 O 41 , Sr 2 V 4 Te 2 O 16 ·H 2 O, and Cd 4 V 2 Te 3 O 15 , which have a wide range of compositions and structural diversity. Only four of them, namely, Sr 4 V 2 Se 6 O 21 , Pb 4 V 2 Se 6 O 21 , Pb 4 V 6 Se 3 O 25 ·H 2 O, and Cd 4 V 2 Te 3 O 15 , have noncentrosymmetric structures ,, and show powder SHG response equivalent to 3.2, 3.7, 0.2, and 1.4 of KDP, respectively, and the remaining 15 compounds have centrosymmetric structures.…”