Faculty of Chemistry, University of Wroclaw, 14 F. Joliot-Curie, 50-383 Wroclaw, Poland.
J Chem Phys. 2013 Apr 7;138(13):134313. doi: 10.1063/1.4798637.
The complicated nature of the chemical bonding in cis and trans isomers of F-O-N=O is discussed based on the results obtained from the topological analysis of electron localization function (η) (ELF), electron localizability index (Y(D)(σ)), and electron density (ρ). The calculations have been performed for correlated wavefunctions using the CCSD and CASSCF methods. The F-O1 bond with non-bonding basins, V(F) and V(')(O1), belongs to the protocovalent type (η,Y(D)(σ)) and its total population ranges between 0.2 and 0.4e. The central N-O1 bond in the cis form is protocovalent (η, Y(D)(σ)) with two basins, V(N) and V(O1). The total population oscillates between 0.7 and 0.9e. In the trans isomer, topology of ELF depends on used method. At the CCSD level only one non-bonding basin, V(N), is observed (η). Its population is about 0.5e. According to the definition of a heteronuclear charge-shift (CS) bond, only N-O1 bond in trans-FONO belongs to the CS class. A relation between η- and ρ-topology and N-O1 bond length is discussed.
顺式和反式 F-O-N=O 异构体中化学键的复杂性质基于电子定域函数（ELF）、电子局域化指数（Y(D)(σ)）和电子密度（ρ）的拓扑分析结果进行讨论。使用 CCSD 和 CASSCF 方法对相关波函数进行了计算。带有非键合基的 F-O1 键，V(F)和 V(')(O1)，属于原始共价型（η，Y(D)(σ)），其总布居数在 0.2 到 0.4e 之间。顺式中中心的 N-O1 键是原始共价的（η，Y(D)(σ)），带有两个基，V(N)和 V(O1)。总布居数在 0.7 到 0.9e 之间振荡。在反式异构体中，ELF 的拓扑结构取决于所使用的方法。在 CCSD 水平上，只观察到一个非键合基，V(N)（η）。其布居数约为 0.5e。根据杂核电荷转移（CS）键的定义，只有反式-FONO 中的 N-O1 键属于 CS 类。讨论了 η-和 ρ-拓扑与 N-O1 键长之间的关系。
