An ab initio study of 15N-11B spin-spin coupling constants for borazine and selected derivatives.
Ab initio equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) calculations have been performed to investigate substituent effects on coupling constants for borazine and selected substituted borazines. For molecules in which F atoms are not bonded to adjacent atoms in the ring, F substitution increases the one-bond (11)B-(15)N coupling constants involving the atom at which substitution occurs but leaves the remaining one-bond B-N coupling constants essentially unchanged. For these molecules, the magnitudes of one-bond B-N coupling constants are only slightly dependent on the number of F atoms present. Fluorine substitution at adjacent B and N atoms in the borazine ring further increases the one-bond B-N coupling constant involving the substituted atoms and has the same effect on the other one-bond coupling constants as observed for corresponding molecules in which substitution occurs at alternate sites. In contrast to the effect of F substitution, substitution of Li at either N or B decreases one-bond B-N coupling constants relative to borazine. The effects of F and Li substitution on one-bond B-N coupling constants for borazine are similar to F and Li substitution effects on (13)C-(13)C coupling constants for benzene.
Del Bene
Janet E
JE
Department of Chemistry, Youngstown State University, Youngstown, Ohio 44555, Instituto de Química, Médica, CSIC, Juan de la Cierva, 3, E-28006 Madrid, Spain. jedelbene@ysu.edu
Elguero
José
J
Alkorta
Ibon
I
Yañez
Manuel
M
Mó
Otilia
O
D001554:Benzene / Q000737:chemistry; D001895:Boron / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D003198:Computer Simulation; D007554:Isotopes / Q000737:chemistry; D008094:Lithium / Q000737:chemistry; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*
D001896:Boron Compounds; D007554:Isotopes; D008094:Lithium; C522695:borazine; D001554:Benzene; D009584:Nitrogen; D001895:Boron