the conformational behavior of monosubstituted tri-methylsilyle ethynyl derivative of cal ix[4]arene as a newgeneration of caliarene was compared with tetra alkylated calyx[4]arene. the most important conformationalphenomena in these compounds which are pinched cone interconversion process were done by semi-empiricalmethod and ab initio calculations with gaussian 98w programming.

The conformational behavior of monosubstituted tri-methylsilyle ethynyl Derivative of Cal ix[4]arene as a newgeneration of Caliarene was compared with tetra alkylated calyx[4]arene. The most important conformationalphenomena in these compounds which are pinched cone interconversion process were done by semi-empiricalmethod and ab initio calculations with Gaussian 98w programming.

Alkoxy side-chain-flanked diarylsulfonamide serves as a reliable structural motif for constructing macrocyclic aromatic tetrasulfonamides. This 90 degrees structural motif is persistent both in solution and in the solid state, which allows the one-step formation of tetrasulfonamide macrocycles. These macrocycles adopt a cone-shaped conformation in solution and in the solid state. For each molec...

Comprehensive two-dimensional gas chromatography (GC x GC) is shown to provide information on dynamic molecular behaviour (interconversion), with the interconversion process occurring on both columns in the coupled-column experiment. The experiment requires suitable adjustment of both experimental conditions and relative dimensions of each of the columns. In this case, a longer column than norm...

The organization of lipids surrounding membrane proteins can influence their properties. We have used 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan) to study phase coexistence and phase interconversion in membrane model systems. The fluorescence properties of Laurdan provide a unique possibility to study lipid domains because of the different excitation and emission spectra of this probe in ...

We present quantum dynamical calculations on the conformational changes of glycine in collisions with the He, Ne, and Ar rare-gas atoms. For two conformer interconversion processes (III-->I and IV-->I), we find that the probability of interconversion is dependent on several factors, including the energy of the collision, the angle at which the colliding atom approaches the glycine molecule, and...

The interconversion of ortho-hydrogen (oH(2)) and para-hydrogen (pH(2)), the two nuclear spin isomers of dihydrogen, requires a paramagnetic spin catalyst such as a nitroxide. We report the design and demonstration of spin catalysis of the interconversion of oH(2) and pH(2) incarcerated in an endofullerene based on a reversible nitroxide/hydroxylamine system. The system is an example of a rever...