Synthesis and structural characterization of the novel tetrahedral MNiFeS clusters containing functionally substituted cyclopentadienyl ligands ( η5-RC 5H 4( η5-C 5H 5)MNiFeS(CO) 5 (M = Mo, W ; R = CHO, CH3CO, CH 3O 2C, CH 2OH, CH(OH)CH 3, (NO 2) 2C 6H 3NHN). The crystal molecular structure of ( η5-CHOC 5H 4( η5-C 5H 5)MoNiFeS(CO) 5

Abstract

A series of functionally substituted cyclopentadienyl MNiFeS clusters ( η 5-RC 5H 4( η 5-C 5H 5)MNiFes(CO) 5 ( 1, M = Mo, R = CHO; 2, M = W, R = CHO; 3, M = Mo, R = CH 3CO; 4, M = W, R = CH 3CO; 5, M = Mo, R = CH 3O 2C; 6, M = W , R = CH 3O 2C) were successfully synthesized by isolobal displacement reactions of corresponding functional cyclopentadienyl MCoFeS clusters η 5-RC 5H 4MCoFeS(CO) 8 with nickelocene in THF at reflux. Further treatment of clusters 1–4 with reducing NaBH 4 at r.t. in MeOH yielded primary and secondary alcohol cluster derivatives ( 7, M = Mo, R = CH 2OH ; 8, M = W , R = CH 2OH; 9, M = Mo, R = CH(OH)CH 3 ; 10, M = W, R = CH(OH)CH 3), which could react with the alkylating reagent Et 3OBF 4 to give ether cluster derivatives ( 11, M = Mo, R = CH(OC 2H 5)CH 3; 12, M = W, R = CH(OC 2H 5)CH 3). Although reactions of clusters 1 and 2 with an aqueous acid solution of 2,4-dinitrophenylhydrazine at r.t. led to almost complete decomposition of the starting clusters, the reactions of clusters 3 and 4 under similar conditions afforded phenylhydrazone cluster derivatives ( 13, M = Mo, R = 2,4-(NO 2) 2C 6H 3NHN ; 14, M = W, R = 2,4-(NO 2) 2C 6H 3NHN). All these novel cluster products have been characterized by elemental analysis and spectroscopic techniques, as well as for cluster 1 by X-ray crystallographic study.