Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (04): 694-700.doi: 10.3866/PKU.WHXB20090408

• ARTICLE • Previous Articles     Next Articles

Effect of Meso-Substituents on β 1H-NMR of A3 Type Corrole

 LIU Hai-Yang, LENG Ke, HU Jun, YING Xiao, XU Zhi-Guang, CHANG Chi-Kwong   

  1. Department of Chemistry, South China University of Technology, Guangzhou 510641, P. R. China; Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, P. R. China; Department of Applied Physics, South China University of Technology, Guangzhou 510641, P. R. China; School of Chemistry and Environment, South China Normal University, Guangzhou 510631, P. R. China
  • Received:2008-11-11 Revised:2009-01-10 Published:2009-03-31
  • Contact: LIU Hai-Yang, CHANG Chi-Kwong E-mail:chhyliu@scut.edu.cn;chang@ust.hk

Abstract:

Geometries of eight A3-type corroles bearing different substituents were optimized and their nuclear magnetic resonance(NMR) propertieswere also calculated using density functional theory (DFT). Geometry optimization results showed that the NH tautomerization of 5,10,15-tris(phenyl)corrole is accompanied by the twisting of its phenyl groups. Although the total energies of both corrole NH tautomers are similar, the Boltzmann distribution probabilities of the A and B tautomers are significantly different. It is also dependent on the meso-substituents. Boltzman statistic averaging should thus be used to evaluate the 1H-NMR of corrole. NMR calculations performed at B3LYP/6-311+G (2d,p)//B3LYP/6-31G(d,p) level may give reasonable 1H-NMR chemical shifts for the corrole. β-H chemical shifts were proportional to the Hammett constants σ+P of the substituents. Furthermore, because of the low symmetry of corrole, the substituents exerted a different effect on the NMR of β-protons at different positions. The order of 1H-NMR chemical shifts for different β-H is quite sensitive to the nature of meso-substituents. β1H-NMR is determined by the electronic effect of substituents and the geometrical structure of the corrole.

Key words: Corrole, 1H-NMR, Gauge-independent atomic orbital, Density functional theory

MSC2000: 

  • O641