TY - JOUR
T1 - Internal bond rotation in substituted methyl radicals, H2B-CH2, H3C-CH2, H2N-CH2, and HO-CH2
T2 - Hardness profiles
AU - Uchimaru, Tadafumi
AU - Chandra, Asit K.
AU - Kawahara, Shun Ichi
AU - Matsumura, Kazunari
AU - Tsuzuki, Seiji
AU - Mikami, Masuhiro
PY - 2001/3/1
Y1 - 2001/3/1
N2 - The energy profiles for the internal bond rotation of substituted methyl radicals, X-CH2 (X = BH2, CH3, NH2, and OH) were examined with B3LYP/6-31G(d) calculations. Energy evaluation of each point along the rotational coordinate was also carried out with single-point calculation at the computational levels of B3LYP/ 6-311+G(2df,p) and QCISD(T)/6-311+G(2df,p). The computed rotational energy profiles, as well as the calculated values for the geometrical parameters, the vibrational frequencies, and the ionization potential, were in reasonable agreement with previously reported experimental and theoretical results. Except for H3C-CH2 radical, the profiles of chemical potential and hardness along the rotational coordinates present striking contrast to those expected from the corollary of the principle of maximum hardness. Thus, there seems to be no rigorous reason for hardness to be minimum in the transition state region, in general.
AB - The energy profiles for the internal bond rotation of substituted methyl radicals, X-CH2 (X = BH2, CH3, NH2, and OH) were examined with B3LYP/6-31G(d) calculations. Energy evaluation of each point along the rotational coordinate was also carried out with single-point calculation at the computational levels of B3LYP/ 6-311+G(2df,p) and QCISD(T)/6-311+G(2df,p). The computed rotational energy profiles, as well as the calculated values for the geometrical parameters, the vibrational frequencies, and the ionization potential, were in reasonable agreement with previously reported experimental and theoretical results. Except for H3C-CH2 radical, the profiles of chemical potential and hardness along the rotational coordinates present striking contrast to those expected from the corollary of the principle of maximum hardness. Thus, there seems to be no rigorous reason for hardness to be minimum in the transition state region, in general.
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U2 - 10.1021/jp003257s
DO - 10.1021/jp003257s
M3 - Article
AN - SCOPUS:0035281115
SN - 1089-5639
VL - 105
SP - 1343
EP - 1353
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 8
ER -