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为了研究共轭分子的芳香性,我们建立了新的作用能分解法。该方法的核心是为任何一个共轭分子提供一个π和σ体系彻底分离的轨道基组{Φ_m~(P-π),Φ_l~(P-σ),Φ_t~P}。为此,放射形环炔烃分子(D_(3h)对称的)必须分割成3个乙炔片断(A,C,E)和3个乙烯片断(B,D,F),它的{Φ_m~(P-π),Φ_l~(P-σ),Φ_t~P}是由6个片断的轨道基组{ψ_k~(P-π),ψ_n~(P-σ),φ_s~(’P)}(P=A,B,…,F)叠加而成。FMP-L和FMP-R(P=A,B,…,F)是片断P的两个片断分子,设它们C-H_R键的键长分别是r_R(P)和r_L(P)。在定域化后,单占据轨道φ_s~(’P)和参考氢原子H_R占据轨道φ_h~(’H)的总电子数∑q_(?)(P)+∑q_h(P)总是正确的,与r_R(P)和r_L(P)的取值无关。但是,{φ_s~(’P)的空间取向取决于r_L(P)和r_R(P)的值。在片断A和B中,R_V(A)=(-V/T)=1.95153+0.50869*r_R~V(A),R_V(B)=1.94556+0.54823*r_R~V(B),设R_V=2,则r_R~V(A)=0.09528nm,r_R~V(B)=0.09930nm。另外,有条件地优化FMP-R可算得:r_R~O(A)=0.10658nm,r_R~O(B)=0.10888nm。当r_R~V(P)和r_R~O(P)确定后,可得到;q_S~V(A)=6.05124-56.5228*r_L~V(A),q_S~V(B)=5.17915-47.0804*r_L~V(B);q_S~O(A)=5.81883-49.0924*r_L~O(A),q_S~O(B)=4.70043-39.0818*r_L~O(B)。然后设q_S(P)=q_h(P)=(1/4)(∑q_S(P)+∑q_h(P)),可得到:r_L~V(A)=0.08937nm,r_L~V(B)=0.08678nm;r_L~O(A)=0.09816nm,r_L~O(B)=0.09297nm,再由r_R~V(P)和r_L~V(P)计算的{Φ_m~(P-π),Φ_l~(P-σ),Φ_t~P}中,每一对成键单占据轨道Φ_t~P的电子占据数Q_t比较均匀合理,它的12个单占据轨道的电子总占据数为∑Q_t=12.3。另外,在由{Φ_m~(P-π),Φ_l~(P-σ),Φ_t~P}~V算得的FUL态中,轨道分布也是更好地满足FUL态的基本特征。所以r_R~V(P)和r_L~V(P)比r_R~O(P)和r_L~O(P)更为合理。
In order to study the aromaticity of conjugated molecules, we have established a new method of energy decomposition. The core of this method is to provide any one conjugate molecule with a complete orbital basis set {Φ_m ~ (P-π), Φ_l ~ (P-σ), Φ_t ~ P} of π and σ systems. For this purpose, the radial cycloalkyne molecule (D_ (3h) symmetrical) must be partitioned into three acetylene moieties (A, C, E) and three ethylene moieties (B, D, F) (P-π), Φ_l ~ (P-σ), Φ_t ~ P} are composed of six groups {ψ_k ~ (P-π), ψ_n ~ (P = A, B, ..., F). FMP-L and FMP-R (P = A, B, ..., F) are two fragment molecules of fragment P, and their bond lengths of C-H_R bond are r_R (P) and r_L (P), respectively. After localization, the total number of electrons Σq _ (?) (P) + Σq_h (P) of the single occupation orbit φ_s ~ (’P) and the reference hydrogen atom H_R occupying the orbit φ_h ~ (H) is always correct , Regardless of the values of r_R (P) and r_L (P). However, the spatial orientation of {φ_s ~ (’P) depends on the values of r_L (P) and r_R (P). In segments A and B, R_V (A) = (- V / T) = 1.95153 + 0.50869 * r_R ~ V (A) and R_V (B) = 1.94556 + 0.54823 * r_R ~ V , R_R to V (A) = 0.09528 nm and r_R to V (B) = 0.09930 nm. In addition, conditional optimization of FMP-R can be calculated: r_R ~ O (A) = 0.10658nm, r_R ~ O (B) = 0.10888nm. Q_S ~ V (A) = 6.05124-56.5228 * r_L ~ V (A), q_S ~ V (B) = 5.17915-47.0804 * r_L, when r_R ~ V (P) and r_R ~ O ~ V (B); q_S ~ O (A) = 5.81883-49.0924 * r_L ~ O (A), q_S ~ O (B) = 4.70043-39.0818 * r_L ~ O (B). Then, letting q_S (P) = q_h (P) = (1/4) (Σq_S (P) + Σq_h (P)), we get: r_L ~ V (A) = 0.08937nm, r_L ~ V = 0.08678nm; r_L ~ O (A) = 0.09816nm, r_L ~ O (B) = 0.09297nm, then calculated by r_R ~ V (P) and r_L ~ V (P) Φ_l ~ (P-σ), Φ_t ~ P}, the electron occupation number Q_t of each pair of bonding single occupation trajectory Φ_t ~ P is more uniform and reasonable, the total electron occupation of 12 single occupied orbits is ΣQ_t = 12.3. In addition, the orbital distribution is also a basic feature that better satisfies the FUL state in the FUL states calculated by {Φ_m ~ (P-π), Φ_l ~ (P-σ), Φ_t ~ P} ~V. So r_R ~ V (P) and r_L ~ V (P) are more reasonable than r_R ~ O (P) and r_L ~ O (P).