High-Sensitivity Two-Dimensional Observation of Thermal Birefringence Compensation in Laser-Diode Pumped Nd: Glass Laser Rods

We measured the two-dimensional birefringence compensation in laser-diode (LD) pumped Nd:glass (HAP4) laser rods with a high-sensitivity polarimeter. The compensation was performed by inserting a 90° quartz rotator between two identical LD pumped Nd:glass rods with conductive cooling. A considerable reduction of birefringence loss from 9.8% to less than 0.9% after compensation was observed.     

Synthesis and Comparative Analysis of Molecular and Supramolecular Structures of 4,8-Disubstituted 1,5-Dichloro-2,6-dioxotricyclo[5.1.0.0 3,5]octanes

A series of 4,8-disubstituted 1,5-dichloro-2,6-dioxotricyclo-[5.1.0.0^3,5]octanes, synthesized by various methods, were studied by X-ray single crystal diffraction. The conformation (syn/anti) of the molecules does not depend on the method of preparation and nature of substituents. All the compounds crystallize in centrosymmetric space groups with half of the molecules in the asymmetric part of the unit cell. The main influence which the substituents render is on the packing of molecules in crystals and on the types of intermolecular interactions and supramolecular structures.     

Synthesis and Comparative Analysis of Molecular and Supramolecular Structures of 4,8-Disubstituted 1,5-Dichloro-2,6-dioxotricyclo[5.1.0.0 3,5]octanes

Summary. A series of 4,8-disubstituted 1,5-dichloro-2,6-dioxotricyclo-[5.1.0.0^3,5]octanes, synthesized by various methods, were studied by X-ray single crystal diffraction. The conformation (syn/anti) of the molecules does not depend on the method of preparation and nature of substituents. All the compounds crystallize in centrosymmetric space groups with half of the molecules in the asymmetric part of the unit cell. The main influence which the substituents render is on the packing of molecules in crystals and on the types of intermolecular interactions and supramolecular structures.Received November 7, 2002; accepted (revised) December 16, 2002 Published online June 23, 2003     

Palladium-catalyzed cross-coupling reaction: Direct allylation of aryl bromides with allyl acetate

Various aryl bromides underwent a palladium-catalyzed cross-coupling reaction with allyl acetate in the presence of hexa-n-butylditin to give the allylated products in very high yields.     

Three fungitoxic cyclopentanoid sesquiterpenes from stromata of epichloetyphina

New fungitoxic sesquiterpenes, chokol A (1), B (2), and C (3), have been isolated from stromata of $\text{Epichloe}$$\text{typhina}$. Their structures and the relative configuration of 3 have been also elucidated from spectral data.     

Number-conserving treatment of the BCS-Tamm-Dancoff approximation for deformed rare-earth nuclei

The formulation for the exact number-conserving treatment of the BCS-Tamm-Dancoff approximation (NTDA) in deformed even nuclei is given. It is applied to theK ^π=0^? octupole vibrations of rare-earth nuclei and is also compared with the ordinary TDA or RPA method based on the Bogoliubov transformation which has the defect of mixing of the particle number in the wave functions. The excitation energies andB(E3) calculated by NTDA method show rather stronger dependence on the Nilsson orbits than those calculated by the usual TDA or RPA methods, especially atN=94 nuclei.     

Structures of altiloxins a and b,phytotoxins from phomaasparagi sacc

By spectroscopic data, the structures of two new phytotoxins, altiloxins a and b from Phoma asparagi sacc., the incitant of stem blight disease on asparagus are elucidated.