We report XAS studies on several ''Costa type'' compounds with different alkyl groups in the axial position. Especially the XANES part of the spectra shows differences in the electronic and structural features due to the different electronic donor power of the substituent and to a variation of the degree of the octahedral symmetry around the metal site. The EXAFS analysis, performed by using the package GNXAS, has permitted the study of the Co-C bond length dependence on the chemical nature of the alkyl group. The bond length appears to depend on the Taft sigma* constant of the alkyl group. The relationship between the information obtained by EXAFS and XANES analysis is also discussed.
XAS studies on ''Costa type'' model compounds of coenzyme B-12 RID A-8599-2010
M. Berrettoni;MARASSI, Roberto;DI CICCO, Andrea;
1997-01-01
Abstract
We report XAS studies on several ''Costa type'' compounds with different alkyl groups in the axial position. Especially the XANES part of the spectra shows differences in the electronic and structural features due to the different electronic donor power of the substituent and to a variation of the degree of the octahedral symmetry around the metal site. The EXAFS analysis, performed by using the package GNXAS, has permitted the study of the Co-C bond length dependence on the chemical nature of the alkyl group. The bond length appears to depend on the Taft sigma* constant of the alkyl group. The relationship between the information obtained by EXAFS and XANES analysis is also discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
