Nonlinear optical properties in tetrametallic Fe3Mn complexes with pseudo-C3 symmetry

New type of 3D chromophores [{CpFeC5H4single bondCRdouble bond; length as m-dashCHsingle bond4-py}3Mn(CO)3]BF4 (1) with weakly interaction subchromophore were synthesized and found to display improved nonlinearity compared with their 1D reference systems [(CpFeC5H4single bondCRdouble bond; length as m-dashCHsingle bond4-py)Mn(CO)5]BF4 (2).