Novel sterically hindered substituted ferrocenes and their transition metal complexes

Bis(1'-organylthiolatoferrocenylene)disulfanes, RS-fc-SS-fc-SR type I ligands (R = Me, Bu-t), have been synthesized by cleavage of 1,2,3-trithia[3]ferrocenophane with organolithium reagents, RLi. The disulfanes have been successfully cleaved using lithium triethylborohydride and then reacted with dibromo-organyl species (Br-X-Br) to produce a novel series of sterically hindered ligands, RS-fc-S-X-S-fc-SR type II ligands {(1) R = Bu-t; X = CH2CH2CH2, CH2C5H3NCH2, CH2C10H6CH2; (2) R = Me; X = CH2CH2CH2, CH2C5H3NCH2, CH2C10H6CH2}. Both type I and type II ligands have been structurally characterized, and their coordination chemistry has been investigated by reaction with the late transition metal reagents Cu(MeCN)(4)PF6 and Pd(cod)Cl-2. The resulting Cu(I) and Pd(II) complexes have been fully characterized, showing some unusual reactivity and a preponderance for a bis-bidentate chelating mode.