Premium
The structures of LiNC, NaNC, and KNC: Potential energy surface for the orbiting motion of the metal cation around the CN group
Author(s) -
Dorigo Andrea,
von Ragué Schleyer Paul,
Hobza Pavel
Publication year - 1994
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540150307
Subject(s) - chemistry , isomerization , isocyanide , crystallography , electronic correlation , potential energy surface , metal , computational chemistry , stereochemistry , molecule , biochemistry , organic chemistry , catalysis
Sets of X NC ( X = Li, Na, and K) structures have been investigated using a variety of theoretical methods and basis sets. Two linear and a bridged structure correspond to an energy minimum for LiCN. For NaCN and KCN, the linear isocyanide is a minimum at most levels of theory but becomes a second‐order stationary point when correlated levels and large basis sets are used. Two transition structures are involved in the interconversion of the bridged form and each linear isomer. The isomerization of the bridged minimum to the linear X CN involves a substantial barrier in each case, so that the satellite motion of the metal is facile at one end but not at the other. Calculations with large basis sets and with electron correlation, fourth‐order Møller–Plesset theory for KNC, and quadratic configuration interaction [QCISD(T)] for LiNC and NaNC give qualitative and quantitative agreement with this experiment. The sodium and potassium cyanide prefer bridged forms, in contrast to the linear isocyanide LiNC. © 1994 by John Wiley & Sons, Inc.