Study on Isolobal Reactions in Transition Metal Cluster Systems. Synthesis of Heteronuclear Metal Cluster Complexes (η⁵-C₅H₅)(η⁵-RC₅H₄)MoNiFe₂S(CO)₁₀, [(η⁵-C₅H₅)MoNiFe₂S(CO)₁₀]₂[η⁵-C₅H₄C(O)CH₂]₂, [(η⁵-C₅H₅)MoNiFeS(CO)₅][MoCoFeS(CO)₈][η⁵-C₅H₄C(O)CH₂]₂, and [(η⁵-C₅H₅)MoNiFeS(CO)₅]₂[η⁵-C₅H₄C(O)CH₂]₂

Abstract

Reactions of the single-tetrahedral MoNiFeS clusters (η5-C5H5)(η5-RC5H4)Mo NiFeS(CO)5 [R = H (1), MeCO (2), MeO2C (3)] with Fe2(CO)9 in toluene at 45−50 °C gave an isolobal displacement/addition type of products (η5-C5H5)(η5-RC5H4)MoNiFe2S(CO)10 [R = H(4), MeCO (5), MeO2C (6)], whereas the double-tetrahedral MoNiFeS cluster [(η5-C5H5)MoNiFeS(CO)5]2[η5-C5H4C(O)CH2]2 (7) reacted with Fe2(CO)9 under similar conditions to give the same type of reaction product [(η5-C5H5)MoNiFe2S(CO)10]2[η5-C5H4C(O)CH2]2 (8). In contrast to the chemical behavior of such tetrahedral clusters, the tetrahedral MoCoFeS cluster [MoCoFeS(CO)8]2[η5-C5H4C(O)CH2]2 (9) reacted with Cp2Ni in refluxing THF to afford only the isolobal displacement type of products [(η5-C5H5)MoNiFeS(CO)5]2[η5-C5H4C(O)CH2]2 (7) and [(η5-C5H5)MoNiFeS(CO)5][MoCo FeS(CO)8][η5-C5H4C(O)CH2]2 (10). The X-ray molecular structures of 5 and 7 are described, and a possible pathway for the novel reaction yielding the isolobal displacement/addition type of products has been briefly discussed.