Synthesis, Characterization, and Reactivity of the Heterometallic Dinuclear μ-PH<sub>2</sub> and μ-PPhH Complexes FeMn(CO)<sub>8</sub>(μ-PH<sub>2</sub>) and FeMn(CO)<sub>8</sub>(μ-PPhH)
作者:Adam C. Colson、Kenton H. Whitmire
DOI:10.1021/om100736m
日期:2010.10.25
Deprotonation of Fe(CO)(4)PRH2 and treatment with Mn(CO)(5)Br afforded the dinuclear complexes FeMn(CO)(8)(mu-PRH) (1a, R = H; 1b, R = Ph), which contain the relatively rare mu-PH2 and mu-PPhH functionalities. The heterometallic nature of these complexes was confirmed by mass spectrometry, and the molecular structures of 1a and 1b were determined by X-ray diffraction experiments. Deprotonation of 1b and subsequent addition of Mn(CO)(5)Br or AuPPh3Cl yielded the trinuclear complexes FeMn(CO)(8)[mu-PPh(Mn(CO)(5))] (3a) and FeMn(CO)(8)[mu-PPh(AuPPh3)] (3b), both of which were characterized structurally and spectroscopically. Deprotonation of 1a at room temperature resulted in rapid coupling of the deprotonated product [2a](-) with neutral 1a to form M+[FeMn(CO)8(mu(3)-PH)Mn(CO)(4)(mu-PH2)Fe(CO)(4)](-) (M+[4](-)) (M+ = Li+, Na+, K+), the formation of which was observed using in situ infrared spectroscopy. M+[4](-) was found to decompose upon solvent removal, and the structure of [4](-) was elucidated by examination of spectroscopic data. The H-1 NMR spectrum of [4](-) was characterized by first-order [ABMX] and [AMX] spin systems, and ESI-MS data confirmed that [4](-) was formed by direct coupling of [2a](-) with 1a without concomitant fragmentation or loss of CO ligands. Deprotonation of 1a at lower temperatures slowed the coupling process, allowing for the metalation of the monomeric anion [2a](-) by treatment with AuPPh3Cl, the product of which was found to decompose gradually in solution and rapidly upon concentration.