Phase formation studies and crystal structure refinements in the Mn ^II /Te ^IV /O/(H) system

Systematic phase formation studies in the system MnII/TeIV/O/-(H) using either solid-state reactions between stoichiometric MnO:TeO2 mixtures or hydrothermal under basic conditions led to crystal growth of two polymorphs (?-, ?-) MnTeO3, Mn6Te5O16, Mn15(TeO3)14(OH)2 and Mn3(TeO3)2(OH)2. Although ?-MnTeO3 Mn6Te5O16 have been reported previously, structure refinements were missing so far. Whereas crystallizes a unique (space group Pbca, Z=16), (Pnma, Z=4) is isotypic with its Co-homologue. The previously unknown phases ?-MnTeO3 (Pbca, Z=8), ( , Z=3) Mn3(TeO3)2(OH)2 (P63mc, all relationships, namely ZnTeO3, Co15(TeO3)14F2 M3(TeO3)2(OH)2 (M=Ni, Co), respectively. Common structures five manganese(II) oxidotellurate(IV) presence [MnO5] [MnO6] polyhedra isolated trigonal-pyramidal [TeO3] groups (except for one TeIV atoms [TeO4] bisphenoids) as principal building units, which share corners edges [MnO5/6] groups. resulting three-dimensional frameworks are dominated by influence stereochemically active 5 s2 electron lone pair situated at atom, leading channels interstices. Quantitative comparisons corresponding given.