OPENING OF CARBOHYDRATE 5,6-EPOXIDES WITH CHIRAL ACETATE AND PROPIONATE ENOLATE EQUIVALENTS ATTACHED TO THE IRON CHIRAL AUXILIARY [C5H5)FE(CO)(PPH(3))]

The lithium enolate derived from the chiral iron acetyl complex (RS)-[(C5H5)Fe(CO)(PPh3)COCH3] (RS)-1 opens, in the presence of boron trifluoride etherate, the carbohydrate 5,6-epoxides, 5,6-anhydro-3-O-benzyl-1,2-O-isopropylidene-α-D-allofuranose 3, 5,6-anhydro-3-O-benzyl-1,2-O-isopropylidene-β-L-talonofuranose 4, 5,6-anhydro-3-O-benzyl-1,2-O-isopropylidene-α-D-glucofuranose 5, and 5,6-anhydro-3-O-benzyl-1,2-O-isopropylidene-β-L-idofluranose 6 to generate after decomplexation the doubly homologated γ-lactones 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-allo-octafuranurono-5,8-lactone 15, 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-β-L-talono-octafuranurono-5,8-lactone 16, 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-gluco-octafuranurono-5,8-lactone 17, and 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-β-L-ido-octafuranurono-5,8-lactone 18 respectively. The lithium enolate derived from the homochiral iron propionyl complexes (R)-[(C5H5)Fe(CO)(PPh3)COCH2CH3] (R)-2 and (S)-[(C5H5)Fe(CO)(PPh3)COCH3] (S)-2 convert after decomplexation 5,6-anhydro-3-O-benzyl-1,2-O-isopropylidene-α-D-glucofuranose 5 to 7(R)-methyl-3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-gluco-octafuranurono-5,8-lactone 20 and 7(S)-methyl-3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-gluco-octafuranurono-5,8-lactone 22 respectively. © 1994

THE CHARACTERIZATION OF ORGANORUTHENIUM COMPLEXES

Multilayer films of a series of novel organoruthenium compounds have been produced and some of their optical properties have been assessed. The length and type of electronic conjugation have been varied to investigate the resulting effect on the electronic absorption spectra and the second-order optical non-linearity. The thermal stability of this class of materials has been studied and optimized by reducing the length of the hydrophobic chain. A pentyl (C5H11) group has proved to be sufficiently long to maintain the film-forming properties of the compounds

PREPARATION AND CHARACTERIZATION OF ORGANOTRANSITION METAL LANGMUIR-BLODGETT FILMS

A novel organotransition metal complex has been synthesized specifically for use with the Langmuir-Blodgett deposition technique. Characterization data for ruthenium (η5-cyclopentadienyl)-(bistriphenylphosphine)-4-cyano-4″-n-pentyl-p- terphenyl hexafluorophosphate (RuCTP) are presented, confirming that monolayer and multilayer structures have been successfully prepared. Complexing of the ruthenium (η5-cyclopentadienyl)-(bistriphenylphosphine) group to a liquid crystal molecule greatly enhances the electron withdrawing nature of the resulting molecule and, furthermore, induces multilayer formation. Optical second harmonic generation studies have enabled an estimate of the molecular hyperpolarizability to be made. The value of 40×10-50 C3 m3 J-2 is significantly larger than those possessed by many inorganic materials. It has been shown that it is possible to incorporate an average of 1.7 molecules of 4-cyano-4″-n-pentyl-p- terphenyl per molecule of the ruthenium complex into the spaces between the terphenyl chains of the floating RuCTP molecules, resulting in an increased molecular packing density and a corresponding increase of 50% in the second harmonic signal strength. © 1988