Bhattacharjee Rituparna, Roy Ram Kinkar
Department of Chemistry, Birla Institute of Technology and Science, Pilani-333031, Rajasthan, India.
Phys Chem Chem Phys. 2014 Oct 28;16(40):22237-54. doi: 10.1039/c4cp03149k.
In the present study, trends of electronic contribution to molecular electrostatic potential [Vel(r¯)(r=0)], Fukui potential [v(+)f|(r=0) and v(-)f|(r=0)] and hardness potential derivatives [Δ(+)h(k) and Δ(-)h(k)] for isolated atoms as well as atoms in molecules are investigated. The generated numerical values of these three reactivity descriptors in these two electronically different situations are critically analyzed through the relevant formalism. Values of Vel(r¯) (when r → 0, i.e., on the nucleus) are higher for atoms in molecules than that of isolated atoms. In contrast, higher values of v(+)|(r=0) and v(-)|(r=0) are observed for isolated atoms compared to the values for atoms in a molecule. However, no such regular trend is observed for the Δ(+)h(k) and Δ(-)h(k) values, which is attributed to the uncertainty in the Fukui function values of atoms in molecules. The sum of Fukui potential and the sum of hardness potential derivatives in molecules are also critically analyzed, which shows the efficacy of orbital relaxation effects in quantifying the values of these parameters. The chemical consequence of the observed trends of these descriptors in interpreting electron delocalization, electronic relaxation and non-negativity of atomic Fukui function indices is also touched upon. Several commonly used molecules containing carbon as well as heteroatoms are chosen to make the investigation more insightful.
在本研究中，研究了孤立原子以及分子中原子的电子对分子静电势[Vel(r¯)(r = 0)]、福井势[v(+)f|(r = 0)和v(-)f|(r = 0)]和硬度势导数[Δ(+)h(k)和Δ(-)h(k)]的贡献趋势。通过相关形式体系对这两种电子不同情况下这三个反应性描述符的生成数值进行了严格分析。分子中原子的Vel(r¯)值（当r → 0，即在原子核上时）高于孤立原子的该值。相反，与分子中原子的值相比，孤立原子的v(+)|(r = 0)和v(-)|(r = 0)值更高。然而，对于Δ(+)h(k)和Δ(-)h(k)值未观察到这种规律趋势，这归因于分子中原子的福井函数值的不确定性。还对分子中的福井势之和以及硬度势导数之和进行了严格分析，这表明了轨道弛豫效应在量化这些参数值方面的有效性。还涉及了这些描述符所观察到的趋势在解释电子离域、电子弛豫和原子福井函数指数的非负性方面的化学后果。选择了几种常用的含碳以及杂原子的分子，以使研究更具洞察力。
