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Surface electrostatic potentials of halogenated methanes as indicators of directional intermolecular interactions
Author(s) -
Brinck Tore,
Murray Jane S.,
Politzer Peter
Publication year - 1992
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560440709
Subject(s) - chemistry , halogen , electrophile , intermolecular force , pyridine , computational chemistry , lone pair , hexafluorobenzene , tetrahydrofuran , halogen bond , ab initio , benzene , fluorine , nucleophile , molecule , chemical physics , alkyl , organic chemistry , solvent , catalysis
Using an ab initio self‐consistent‐field molecular orbital approach, we have computed 6‐31 G *// STO ‐3 G * electrostatic potentials for CH 3 F, CF 4 , CH 3 Cl, CCl 4 , CH 3 Br, and CBr 4 . It is demonstrated that the potentials along the carbon–halogen bonds of these systems can explain the observed directional preferences of the halogens' intermolecular interactions. Our surface potentials for the chlorinated and brominated molecules favor the observed “side‐on” and “head‐on” interactions with electrophiles and nucleophiles, respectively, of CCl and CBr in crystals, whereas the potentials of CH 3 F and CF 4 are indicative of fluorine interacting only with electrophiles, as is found experimentally. The strongly positive potentials at the ends of the chlorines and bromines in CCl 4 and CBr 4 are consistent with complexes that these form with electron donors, e.g., the π regions of benzene and p ‐xylene and the lone pairs of pyridine and tetrahydrofuran. © 1992 John Wiley & Sons, Inc.