1,2:5,6-Di-O-iso-propyl-idene-3-C-methyl-α-d-allo-furan-ose.

The title carbohydrate, C13H22O6, is a derivative of d-glycose, in which the furan-osidic and iso-propyl-idene rings are in twisted conformations. The mean plane of the furan-osidic ring makes a dihedral angle of 70.32 (18)° with the mean plane of the fused iso-propyl-idene ring.

Cobalt lawsone complexes: searching for new valence tautomers.

Bi-stable molecular systems presenting valence tautomerism are associated with the development of new functional materials, which can be used for applications in organic electric conductors, optoelectronic and molecular magnetic devices. The properties of these materials can be adjusted with slight chemical changes and can be induced by external stimuli. Typical examples of valence tautomer compounds are coordination complexes of Co and o-dioxolene ligands, notably quinone like ones.

Aqua-(4,4'-bipyridine-κN)bis-(1,4-dioxo-1,4-dihydronaphthalen-2-olato-κO,O)zinc 4,4'-bipyridine mono-solvate dihydrate.

The reaction of 2-hy-droxy-1,4-naphtho-quinone and 4,4'-bipyridine with zinc acetate produced the title compound, [Zn(C(10)H(5)O(3))(2)(C(10)H(8)N(2))(H(2)O)]·C(10)H(8)N(2)·2H(2)O. The bond lengths and angles around the metal atom indicate a deviation from octa-hedral geometry. The two naphtho-quinone ligands coordinate in a cis fashion, with the 4,4'-bipyridine ligand and the water mol-ecules completing the coordination sphere of the metal atom.