The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of...The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of pure (CH_3CH_2)_3N and thiophenol, these values are moved to high position, and the width of these peaks is obviously increased. These characteristics conformed to NMR spectra of paramagnetic compounds and their molecular structures. The paramagnetic property of these compounds was also studied with ESR spectrum. Mass spectra of three compounds were determined. The main fragments were observed, for example, m/z: 130〔(C_2H_5)_4N〕+, 264〔Fe_3S_3〕+, 144〔Fe-S-Fe〕+, 120〔S-Fe-S〕+, 88〔Fe-S〕+, 136〔FeBr〕+, 91〔FeCl〕+ etc. These supported structural characteristics of the anion skeleton and molecules strongly. The possible mechanism of fragmentation was discussed.展开更多
The accurate equilibrium structures of S_3 and S_3^- are determined by the coupled-cluster method with single, double excitation and perturbative triple excitation(CCSD(T)) with basis sets of aug-cc-pV(n+d)Z(n = T, Q,...The accurate equilibrium structures of S_3 and S_3^- are determined by the coupled-cluster method with single, double excitation and perturbative triple excitation(CCSD(T)) with basis sets of aug-cc-pV(n+d)Z(n = T, Q, 5, or 6), complete basis set extrapolation functions with two-parameters and three-parameters, together with considering the contributions due to the core-valence electron correlation, scalar relativistic effects, spin–orbit coupling, and zero-point vibrational corrections. Our calculations show that both the neutral S_3 and anion S_3^- have open forms with C_(2r) vsymmetry. On the basis of the stable geometries, the adiabatic electron affinity of S_3 is determined to be 19041(11) cm^(-1), which is in excellent agreement with the experimental data(19059(7) cm^(-1)). The dependence of geometries and electron affinity on the computation level and physical corrections is discussed. The present computational results are helpful to the experimental molecular spectroscopy and bonding of S_3.展开更多
文摘The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of pure (CH_3CH_2)_3N and thiophenol, these values are moved to high position, and the width of these peaks is obviously increased. These characteristics conformed to NMR spectra of paramagnetic compounds and their molecular structures. The paramagnetic property of these compounds was also studied with ESR spectrum. Mass spectra of three compounds were determined. The main fragments were observed, for example, m/z: 130〔(C_2H_5)_4N〕+, 264〔Fe_3S_3〕+, 144〔Fe-S-Fe〕+, 120〔S-Fe-S〕+, 88〔Fe-S〕+, 136〔FeBr〕+, 91〔FeCl〕+ etc. These supported structural characteristics of the anion skeleton and molecules strongly. The possible mechanism of fragmentation was discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874179,11447194,11574114,and 11874177)the Natural Science Foundation of Jilin Province,China(Grant No.20180101289JC)
文摘The accurate equilibrium structures of S_3 and S_3^- are determined by the coupled-cluster method with single, double excitation and perturbative triple excitation(CCSD(T)) with basis sets of aug-cc-pV(n+d)Z(n = T, Q, 5, or 6), complete basis set extrapolation functions with two-parameters and three-parameters, together with considering the contributions due to the core-valence electron correlation, scalar relativistic effects, spin–orbit coupling, and zero-point vibrational corrections. Our calculations show that both the neutral S_3 and anion S_3^- have open forms with C_(2r) vsymmetry. On the basis of the stable geometries, the adiabatic electron affinity of S_3 is determined to be 19041(11) cm^(-1), which is in excellent agreement with the experimental data(19059(7) cm^(-1)). The dependence of geometries and electron affinity on the computation level and physical corrections is discussed. The present computational results are helpful to the experimental molecular spectroscopy and bonding of S_3.
