ISSN:
0192-8651
Keywords:
Computational Chemistry and Molecular Modeling
;
Biochemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Computer Science
Notes:
Heats of formation, atomic charges, and geometries of some 110 structures involving substituted singlet and triplet phenyl and 4,4-dimethyl-1,4-dihydronaphthalene carbenes and the corresponding diazomethanes were calculated by MINDO/3, MNDO, AM1, and PM3 semiempirical molecular orbital methods. The singlet-triplet gaps for AM1 and PM3 calculations for the para derivatives in both systems have been successfully correlated with Brown σ+ constants. Good correlations with σ+ were found for the charges on the carbenic centers of the singlets as well as with the energy barrier for rotation of the aryl group about the C-C single bond in substituted singlet phenylcarbenes. Comparisons of these results with experimental data indicate that AM1 and PM3 are much better than MNDO and MINDO/3 in predicting the intrinsic substituent effects in singlet carbenes.
Additional Material:
8 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcc.540120503
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