Accession Number : AD0681364

Title :   SEMIEMPIRICAL MOLECULAR ORBITAL CALCULATIONS ON BORANES i; arylboronic acids or esters.

Descriptive Note : Terminal rept. Sep 66-Sep 68,

Corporate Author : AKRON UNIV OHIO DEPT OF CHEMISTRY

Personal Author(s) : Ramsey,Brian G. ; Ito,Hirotoshi

Report Date : SEP 1968

Pagination or Media Count : 29

Abstract : Traditional Pariser-Parr-Pople and variable electronegativity calculations have been carried out on C6H5B(OR)2 and p-CH3OC6H4B(OR)2, and the results compared with calculations for C6H5BR2. It is concluded that the VESCF method offers a real advantage over the simple PPP method for predicting percent charge transfer and transition intensity in cases where excited states possess substantial C.T. character. The restriction that empirically chosen parameters fit the observed transition energies and intensities of both triarylboranes and ArB(OR)2 requires the choice of a boron VSIP greater than 2.0 ev in the fixed parameter procedure of the usual PPP-SCF-CI method for these molecules. Observed transitions in C6H5B(OR)2 correlate with 1Lb, 1La, 1Bb, whereas the first absorption maximum of (C6H5)3B is assigned to C.T. (1A1 to 1A1) local C2v symmetry. (Author)

Descriptors :   (*BORANES, *MOLECULAR ORBITALS), ACIDS, ESTERS, WAVE FUNCTIONS, ELECTRON DENSITY, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA, CHEMICAL BONDS, MATRICES(MATHEMATICS)

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE