Belokoneva Elena L, Stefanovich Sergey Yu, Dimitrova Olga V, Karamysheva Alina S, Volkov Anatoly S
Geological Faculty, Department of Crystallography, Lomonosov Moscow State University , Leninskije Gory 1, Moscow, 119992 GSP2, Russia.
Chemical Faculty, Laboratory of Functional Materials, Lomonosov Moscow State University , Leninskije Gory 1, Moscow, 119992 GSP2, Russia.
Inorg Chem. 2017 Feb 6;56(3):1186-1192. doi: 10.1021/acs.inorgchem.6b02191. Epub 2017 Jan 9.
Single crystals of two new iodide-iodates, Bi[IO]·AgI and Tb[IO]·AgI, are synthesized in hydrothermal systems. The anionic parts in both iodide-iodates are characterized as a complex charged framework of isolated IO umbrella-like groups and large Bi(Tb)-O polyhedra similar to those previously found in La[IO]IO. Broad channels along the c-axis contain compensators: (AgI) umbrella-like groups and additional Ag ions which form Ag tetrahedral clusters augmented with I halogen. New iodates possess significantly higher second-order nonlinear optical characteristics compared to the previously known lead-containing compounds REE[IO]IO, REE = La, Pr, Nd. The difference is related to the polar ordering of umbrella-like (AgI) groups in the channels in the new iodide-iodate. Additionally, planar-coordinated Ag atoms add three Ag atoms in umbrellas forming [AgI] polar clusters in the channels.
