Two synthetic routes, the direct reaction of a carbohydrate with ⁺COCCo₃(CO)₉, or the reaction of Co₂(CO)₈ with 1,1,1-tribromomethyl sugar derivatives have been used to prepare [AcOglc = tetra-O-acetyl-D-glucopyranose, Co₃ = CCo₃(CO)₉] 1-β-AcOglc-N-(CO)-Co_3,, 2-β-AcOglc-N-(CO)-Co_3,, 1-α- (16) and 1-β-AcOglc-OCH₂Co₃, 1-α-BnOglc-O-(CO)Co₃ and 1-α- and 1-β-AcOmaltose-OCH₂Co₃. An unusual oxazoline cluster was isolated from the reaction with 2-aminoglucose. An X-ray structure confirmed the structure and absolute configuration of 16. Deprotection of 1-β-AcOglc-OCH₂Co₃ on ion exchange resin gave water soluble 1-β-glc-OCH₂Co₃; higher yields of water soluble complexes were obtained by direct reaction of deprotected trihalomethyl derivatives with Co₂(CO)₈. Dppm complexes of the OCH₂Co₃ glucose derivatives were also prepared. Reaction of ⁺COCCo₃(CO)₉ with methyl-α-D-glucopyranoside gave the series 1-MeOglc-3-Co₃, 1-MeOglc-3,6-(Co₃)₂, 1-MeOglc-2,3,6-(Co₃)₃ and 1-MeOglc-3,4,6-(Co₃)₃, structurally characterised by 2-D ¹H and ¹³C NMR. The carbohydrate-cluster complexes show reversible redox activity in organic and aqueous media.