摘要
应用密度泛函方法(DFT)计算了铁硫金属蛋白中的铁硫簇[Fe_2S_2(SCH_3)_4]^()2-,[Fe_3S_4(SCH_3)_3]^(2-)以及[Fe_4S_4(SCH_3)_4]^(2-)的几何参数和磁偶合性质.采用对称性破缺态(BS)来描述Fe—Fe自旋偶合.计算结果表明:采用高自旋态(HS)计算的Fe—Fe间距与实验值有较大偏差,而由BS方法所计算的Fe—Fe间距与晶体结构测定数据相吻合.根据HS态和BS态的能量,计算了体系的海森堡偶合参数J,计算结果也较为接近实验估算值.
Density functional theory (DFT) has been used to calculate geometies and magnetic properties of iron - sulfur clusters [Fe2S2(SCH3)4]2-, [Fe3S4(SCH3)3]2- and [Fe4S4(SCH3)4]2- in the active sites of FeS proteins. The Fe-Fe spin coupling is described by a broken symmetry (BS) state. The calculations show that the Fe-Fe distances obtained from high spin state (HS) are deviated from the experimental values significantly, whereas the Fe-Fe distances obtained by BS method are in good agreement with crystal structure data. Based on the energies of HS and BS states, Heisenberg coupling constant J of these clusters can be estimated and the calculated J values compare fairly well with the experimental data.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2000年第12期1529-1533,共5页
Acta Chimica Sinica
