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(1→4)- and (1→6)-linked disaccharides were epimerized at C-2 of the reducing terminal under mild conditions by calcium(II)–N-alkylated monoamine systems. Naturally rare (1→4)-linked heterodisaccharides having a D-mannose unit as a reducing terminal can be prepared in one step from disaccharides having a D-glucose unit which are abundunt in nature.

The first ruthenium analogue of hemerythrin models with µ-alkoxo bridging, Na[Ru(dhpta)(µ-O2CR)2] (1: R = CH3, 2: R = C6H5, 3: R = C6H4-p-OH, 4: R = C6H4-p-NH2) have been prepared and characterized, and the crystal structure of 1has been determined; these compounds undergo two one-electron reductions to the RuIIRuIIIand RuIIRuIIstates with large separations (~0.6 V) between the successive redox potentials, allowing the formation of stable mixed-valence species.

When treated with dimethylformaraide (DMF) in benzene at reflux, trans-[W(N2)2(dpe)2] (dpe = Ph2PCH2CH2PPh2) afforded [WH(η2-CONMe2)(dpe)2] and [W(CO)(DMF)(dpe)2]. The structure of the former was fully characterized by X-ray crystallography. The latter reacted with N2to give trans-[W(CO)(N2)(dpe)2].

Aldoses are rapidly epimerized at C-2 by combination of alkaline earth or rare earth metal ions (Ca2+, Sr2+, Pr3+, or Ce3+) and monoamines (triethylamine etc.). 13C NMR studies using [1-13C]-d-glucose of the Ca2+system revealed that this reaction proceeds via the stereospecific rearrangement of carbon skeleton.

(1→6)-Linked disaccharides having mannose as a reducing unit were synthesized from their naturally abundant C-2 epimers by the novel C-2 epimerization promoted by nickel(II)-diamine complex, [Ni(H2O)2(tmen)2]Cl2(tmen = N,N,N′-trimethylethylenediamine).

The synthesis and crystal structure of the nickel(II) complex, [Ni(N,N′-(d-Man)2-tren]Cl2·CH3OH containing two N-glycosides derived from the reaction of d-mannose (d-Man) and N,N-di(2-aminoethyl)ethylenediamine (tren) are reported. The suagr part in the complex involves novel intramolecular sugar–sugar hydrogen bondings around the metal center.

A 1D anisotropic hexaplatinum chain with redox-active terminal ligands, [Pt6(µ-H)(µ-dpmp)4(FcDipNC)2](PF6)3(7) (dpmp: bis(diphenylphosphinomethyl)phenylphosphine, FcDipNC: 2,6-diisopropyl-4-(ferrocenylethynylene)phenyl isocyanide), was synthesized, its structure and electrochemical behavior were elucidated in comparison with those of [Pt6(µ-H)(µ-dpmp)4(DipNC)2](PF6)3(6) (DipNC: 2,6-diisopropylphenyl isocyanide), and the module was found to undergo two stepwise two-electron oxidations.

Two 1,3-propanediamine derivatives bearing sugar units, 1,3-diamino-2-propyl ß-d-glucopyranoside (2-β-d-Glc-pn) and 1,3-diamino-2-propyl α-d-mannopyranoside (2-α-d-Man-pn), have been prepared and characterized. The structures of two peracetylated diazides, as well as a nickel complex of glucose-type ligand, [Ni(2-β-d-Glc-pn)2SO4] have been determined by X-ray crystallography.