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Large scale synthesis of oligoribonucleotides has been successfully performed on PEG support by the phosphoramidite approach using t-butyldimethylsilyl to protect the 2'-hydroxyl group of ribonucleoside. By means of this procedure, the dodecamer r(AGUGGUCUUUGU) was synthesized in 98.1% average coupling yield, and 55 mg pure product was obtained from one gram of functionalized PEG.

Two new amorphous high-Tg azobenzene-containing polymers: poly{4-[(2-(methacryloyloxy)ethyl)ethylamino]-4'-(methylsulfonyl)azobenzene} (pDRSAM) and poly{4-[(2-(methacryloyloxy)ethylsulfonyl]-4'-(diethylamino)azobenzene}(pDRASM), having side group dipoles of the same strength but differently bound to the main chain, and a series of copolymers of various compositions, have been synthesized.

The synthesis and optical properties of a series of amorphous polyesters with amino-sulfone azobenzene chromophores in the main chain are presented. The condensation of alkyl diacid chlorides with 4-[(2-hydroxyethyl)ethylamino]-4′-(2-hydroxyethylsulfonyl)azobenzene (7) gave polymers that showed low and unstable photoinduced birefringence because of their low glass-transition temperature. The condensation of 7 with mixtures of adipoyl chloride and terephthaloyl chloride gave a polymer with a higher glass-transition temperature and a stable reversible photoinduced birefringence. A photostationary birefringence of 0.07 was observed. Surface profile gratings were optically inscribed and produced diffraction efficiencies less than or equal to 19%. Photostationary, long-term stable birefringence and surface-grating efficiency increased with polymer rigidity. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2245–2253, 2000

Two new ferroelectric liquid crystals, 4-[(S)-1-(ethoxycarbonyl)]ethyl 4-[4-(9-decenyloxy)biphenyl]azobenzoate (10) and its ester analogue 4-[(S)-1-(ethoxycarbonyl)]ethyl {[4-(9-decenyloxy)]biphenyl-4'-yl}carbonyloxybenzoate (17), and side chain polysiloxane copolymers and terpolymers containing various amounts of 10 and 17 as mesogenic side groups have been synthesized. Their mesomorphic and physical properties have been characterized. Both 10 and 17 exhibit isotropic, SmA*, SmC*, and Sm(I or F)* phases. The copolymer with 17 as the mesogenic group and terpolymers having low content of the azo compound 10 show a SmC* phase over a large temperature range down to room temperature. The copolymer with the azo compound 10 as the mesogenic group is amorphous.

In the present paper we describe the preparation of a novel crystalline phosphonylating agent 9-fluorenemethyl phosphonic acid 2 and a convenient and efficient method for the synthesis of nucleoside H-phosphonates 5.

In the present paper we describe the preparation of a novel crystalline phosphonylating agent 9-fluorenemethyl phosphonic acid 2 and a convenient and efficient method for the synthesis of nucleoside H-phosphonates 5.