Ab initio study of substituted 2-aminoethylborinates
Por:
Höpfl H., Galván M., Farfán N., Santillan R.
Publicada:
1 ene 1998
Resumen:
A series of 2-aminoethylborinate derivatives has been studied by ab initio calculations at the HF/6-31G** level in order to obtain information about the substituent effects around the coordinative N ? B bond. Their geometries were fully optimized and the electrostatic charge, the bond order of the Mulliken population analysis and the hybridization of the different atoms were determined. Based on these data it can be shown that the N ? B bond strength depends on two factors: the polarization along the N ? B bond and the electrostatic repulsive interactions between the substituents around this bond. It was determined that the bond strength can be increased by the introduction of electronegative substituents at the nitrogen atom. Also, it was concluded that the conformations adopted by the five-membered heterocyclic rings depend on the electrostatic interactions around the O-B-N fragment. As a consequence of these interactions, the boron atom is displaced out of the molecular plane, when the nitrogen atom is substituted by at least one methyl group. Otherwise it is one of the carbon atoms of the ring. © 1998 Elsevier Science B.V.
Filiaciones:
Höpfl H.:
Departamento de Química, Ctro. Invest. y de Estud. Avanzados, Inst. Politécnico Nacional, Apdo. Postal 14-740, 07000 Mexico, D.F., Mexico
Galván M.:
Depto. de Quimica, Univ. Autónoma Metropolitana, Unidad Iztapalapa, Apdo. Postal 55-534, 09340 México, D.F., Mexico
Farfán N.:
Departamento de Química, Ctro. Invest. y de Estud. Avanzados, Inst. Politécnico Nacional, Apdo. Postal 14-740, 07000 Mexico, D.F., Mexico
Santillan R.:
Departamento de Química, Ctro. Invest. y de Estud. Avanzados, Inst. Politécnico Nacional, Apdo. Postal 14-740, 07000 Mexico, D.F., Mexico
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