Pseudorotation and conformational transitions in crystal structures having trigonal prismatic coordination

Autor: I. D. Derlugyan, P. D. Derlugyan, V. A. Shchegolev
Rok vydání: 1987
Předmět:
Zdroj: Journal of Structural Chemistry. 28:234-237
ISSN: 1573-8779
0022-4766
DOI: 10.1007/bf00751669
Popis: Kinematic regularities have been examined for the conformational rearrangement of clusters showing trigonal prismatic coordination. Pseudorotation is postulated in an MX/sub 6/ coordination polyhedron, and it has been found that conformation transitions can occur without disrupting most of the bonds. A kinematic cell has been identified in the transition-metal dichalcogenides MX/sub 2/ as a pair of trigonal prisms linked by lateral edges, whose conformation features are similar to those of boat-shaped rings. It is found that the conformation changes in parts of the MX/sub 2/ structure can occur in two ways: by matched rearrangements of chains linking flexible rings or by local transformation of the ring segments. The equilibrium conformations of structurally flexible fragments have been examined: linear, clump-convoluted, and spiral. There is a discussion of the scope for a rotational isomeric mechanism for rearrangement involving trigonal prismatic coordination in glide and in polytype transitions.
Databáze: OpenAIRE
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