A DFT study of the magnetic properties and the iron–iron interaction in the Cp2Fe2(μ–η1–S2,μ–η2–S2) and Cp2Fe2(μ–(η2,η1)–S2)2 isomers of the Cp2Fe2S4 complex

摘要: Abstract Two isomers ( A and B ) of the Cp 2 Fe S 4 complex, which differ by coordination mode units (μ–η 1 –S ,μ–η 2(μ–(η ,η )–S for , respectively, were studied means density functional theory calculations using B3LYP functional. Both optimised in their lowest singlet triplet states. Spin-restricted (RB3LYP) state led to theoretical parameters (in particular Fe⋯Fe distance) satisfactory agreement with experimental values, but also a ground each isomer, result contradiction diamagnetism. The proper order these electronic states was restored spin-unrestricted broken-symmetry (UB3LYP-bs) state. However, geometries are less accurate, metal–metal distance isomer . geometry found this UB3LYP-bs completed an approximate projection on pure