F. Flacke, H. Jacobs
Sep 1, 1995
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0
Influential Citations
6
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Journal
Journal of Alloys and Compounds
Abstract
Abstract Hexaamidostannates(IV) of the alkali metals potassium, rubidium and caesium were prepared by the reaction of tetraphenyl tin with alkali amides in an autoclave made of stainless steel at 385 K with ammonia as solvent. Single crystals were obtained in the form of colourless, transparent hexagonal plates. Their structures were solved by X-ray methods including all hydrogen positions for K 2 [Sn(NH 2 ) 6 ] in the space group R 3 with Z = 3 (hexagonal setting), and for Rb 2 [Sn(NH 2 ) 6 ] and Cs 2 [Sn(NH 2 ) 6 ] in the space group P 3 with Z = 1. K 2 [Sn(NH 2 ) 6 ] a = 6.337(4)A, c=19.769(5) A, F 0 2 ⩾ 3σ( F 0 2 =869, N (var.)=22, R/R W =0.019/0.022 Rb 2 [Sn(NH 2 ) 6 ] a = 6.669(2)A, c=5.771(1) A, F 0 2 ⩾ 3σ( F 0 2 =245, N (var.)=23, R/R W =0.022/0.029 Cs 2 [Sn(NH 2 ) 6 ] a = 6.879(1)A, c=5.850(1) A, F 0 2 ⩾ 3σ( F 0 2 =734, N (var.)=23, R/R W =0.018/0.018 Both structure types contain isolated octahedra units [Sn(NH 2 ) 6 ] 2− . Potassium is coordinated trigonal anti-prismatically by 6 amide ions, rubidium and caesium anti-cuboctahedrally by 12 amide ions. The orientation of the hydrogen atoms is related to the size of the alkali metal ions.