Two-coordinate first row transition metal complexes with short unsupported metal-metal bonds

Article abstract of DOI:10.1021/ja1089777

A series of first row transition metal complexes with unsupported M-Fe bonds, (3,5-ⁱPr₂-Ar*)MFe(η⁵-C ₅H₅)(CO)₂ (M = Fe (1), Mn (2), Cr (3), 3,5-ⁱPr₂-Ar* = -C₆H-2,6-(C ₆H₂-2,4,6-ⁱPr₃)₂-3,5- ⁱPr₂), was synthesized by salt metathesis. They were characterized by ¹H NMR, UV-vis spectroscopy, X-ray crystallography, and SQUID magnetic measurements. Two distinct Fe atoms in 1 were confirmed by Moessbauer spectroscopy. All three compounds feature short metal-metal bond distances (Fe-Fe, 2.3931(8) A (1); Mn-Fe, 2.4512(5) A (2); Cr-Fe, 2.4887(5) A (3)). Their DFT computed structures were in excellent agreement with the experimental data and revealed a dative bonding interaction between the metals.