A mechanism for the aziridination of olefins by aryl azides (ArN3), promoted by ruthenium(ii) porphyrin complexes, is proposed on the basis of kinetic and theoretical studies. All the recorded data support the involvement of a mono-imido ruthenium complex as the active intermediate in the transfer of the nitrene moiety "ArN" to the olefin. The selectivity of the aziridination vs. the uncatalyse...

Two amphiphilic derivatives of chlorophyll, which have high potential as photodynamic therapy sensitizers for malignant melanoma have been investigated by a combination of laser flash photolysis and pulse radiolysis. It is shown that direct excitation of monomeric forms of these molecules in both hydrophilic and hydrophobic environments produces significant yields of the corresponding triplet s...

Entanglement can be generated by two electrons in a spin-zero state on a semiconducting single-walled carbon nanotube. The two electrons, one weakly bound in a shallow well in the conduction band, and the other injected into the conduction band, are coupled by the Coulomb interaction. Both transmission and entanglement are dependent on the well characteristics, which can be controlled by a loca...

A photophysical study of the covalently linked tetracene dimer 1,4-bis(tetracen-5-yl)benzene is presented. While the dimer’s steady state spectroscopy is similar to that of monomeric tetracene, it also exhibits a long-lived fluorescence signal in solution and solid polyethylene films, which is absent in the monomer. The behavior of this long-lived component as a function of temperature and oxyg...

The combined effect of hydrostatic pressure and temperature on correlation energy in a triplet state of two electron spherical quantum dot with square well potential is computed. The result is presented taking GaAs dot as an example. Our result shows the correlation energies are i)negative in the triplet state contrast to the singlet state ii) it increases with increase in pressure  iii)further...

Brief tactile presses stimulated the index and middle fingers of the right and left hands. The stimulation on each hand consisted of a triplet of presses. Each triplet was composed of a brief press to one finger (e.g., the middle finger), followed by a brief press to the other finger (e.g., the index finger), and by a final simultaneous press to both fingers of a given hand. With equal probabil...

We report the simultaneous observation of geminate and nongeminate triplet-triplet annihilation in a solution-processable small molecule TIPS-tetracene undergoing singlet exciton fission. Using optically detected magnetic resonance, we identify recombination of triplet pairs directly following singlet fission, as well as recombination of triplet excitons undergoing bimolecular triplet-triplet a...

Time-resolved triplet exciton transport in binary mixed crystals has been studied for CHin CloDg (20%-100%) at liquid helium temperatures. The delayed fluorescence decays ar~o g ~xponential and range from milliseconds to nanoseconds as Cg goes from 0.2 to 1.0. The analysis IS based on the presence of a BMN supertrap in large amounts (103) and on the fact that supertrapping.o~ th~ guest ex~itons...