ABSTRACTInteractions of cycloheptatriene derivatives, C
7H
6X, (X?=?NH, PH, AsH, O, S, Se) with the cations H
+, CH
3+, Cu
+, Al
+, Li
+, Na
+, and K
+ are studied using B3LYP functional and 6-311++G(d,p) basis set. The calculated gas-phase cation affinities (CA) and cation basicities (CB) for all molecules decrease as H
+ > CH
3+ > Cu
+ > Al
+ > Li
+ > Na
+ > K
+. We used the induced aromaticity in the 7-membered ring of C
7H
6X upon interaction with the cations, M
+, as a measure of C
7H
6X/M
+ interaction. Nucleus-independent chemical shift (NICS) and harmonic oscillator model of aromaticity (HOMA) were used as two indices of aromaticity. The highest and lowest induced aromaticities were observed for interactions of H
+ and K
+, respectively. Also, the aromaticity induced by interaction with a cation in C
7H
6AsH and C
7H
6PH was larger than that in C
7H
6NH and C
7H
6O. Hence, the aromaticity was considered as a measure of covalency for the C
7H
6X/M
+ interactions showing a rational dependence on both the molecule and cation. The nature of the interactions was also assessed using electron density, charge distribution analysis and NBO calculations. The results of the aromaticity indices, NICS and HOMA, were compared with the electron density and NBO results.
相似文献