Synthesis of tetrahedral heteronuclear MoCoFe( μ3-E) (E=S, Se) clusters via isolobal displacement and functional transformation reactions. The crystal molecular structure of η5-MeCOC 5H 4MoCoFe( μ3-Se)(CO) 8

Abstract

The dppe-bridged Mo–Mo singly-bonded dimers ( μ-dppe)( η 5-RC 5H 4) 2Mo 2(CO) 4 (dppe =Ph 2PCH 2CH 2PPh 2; 1a, R=H; 1b, R=MeCO; 1c, R=MeO 2C) prepared by reaction of Mo–Mo triply-bonded dimers ( η 5-RC 5H 4) 2(CO) 2Mo 2(CO) 4 and dppe, reacted with μ 3-Se cluster Co 2Fe( μ 3-Se)(CO) 9 to give single clusters η 5-RC 5H 4MoCoFe( μ 3-Se)(CO) 8 (2a, R=H; 2b, R=MeCO; 2c, R=MeO 2C), whereas the disodium salt [( μ-dppe)( η 5-MeO 2CC 5H 4) 2Mo 2(CO) 4]Na 2 (3) prepared by reaction of 1c and 1% Na/Hg, reacted with μ 3-S cluster Co 2Fe( μ 3-S)(CO) 9 to afford single cluster η 5-MeO 2CC 5H 4MoCoFe( μ 3-S)(CO) 8 (4) and double cluster ( μ-dppe)[( η 5-MeO 2CC 5H 4MoCoFe( μ 3-S)(CO) 7] 2 (5). Further treatment of 2b with NaBH 4 gave a single cluster containing hydroxyl group η 5-MeCH(OH)C 5H 4MoCoFe( μ 3-Se)(CO) 8 (6), which reacted with Et 3OBF 4 to give single cluster η 5-MeCH(OEt)C 5H 4MoCoFe( μ 3-Se)(CO) 8 (7) and double cluster [ η 5-C 5H 4CH(Me)O(Me)CHC 5H 4- η 5][MoCoFe( μ 3-Se)(CO) 8] 2 (8) both containing ether functionality. All the new clusters have been characterized by elemental analysis and spectroscopic methods, as well as by X-ray diffraction analysis for cluster 2b.