Mechanisms of Energy Transfer and Enhanced Stability of Carbidonitride Phosphors for Solid-State Lighting.

Phosphor-converted light emitting diodes (pcLEDs) produce white light through the use of phosphors that convert blue light emitted from the LED chip into green and red wavelengths. Understanding the mechanisms of degradation of the emission spectra and quantum yields of the phosphors used in pcLEDs is of critical importance to fully realize the potential of solid-state lighting as an energy efficient technology. Toward this end, time-resolved photoluminescence spectroscopy was used to identify the mechanistic origins of enhanced stability and luminescence efficiency that can be obtained from a series of carbidonitride red phosphors with varying degrees of substitutional carbon.

Reversible Borylene Formation from Ring Opening of Pinacolborane and Other Intermediates Generated from Five-Coordinate Tris-Boryl Complexes: Implications for Catalytic C-H Borylation.

Catalytic C-H borylation using the five-coordinate tris-boryl complex (dippe)Ir(Bpin) (, dippe = 1,2-bis(diisopropylphosphino)ethane) has been examined using P{H} and H NMR spectroscopy. Compound was shown to react rapidly and reversibly with HBpin to generate a six-coordinate borylene complex, (dippe)Ir(H)-(Bpin)(BOCMeCMeOBpin) (), whose structure was confirmed by X-ray crystallography. Under catalytic conditions, the H generated from C-H borylation converted compound to a series of intermediates.

Electronic effects in iridium C-H borylations: insights from unencumbered substrates and variation of boryl ligand substituents.

Experiment and theory favour a model of C-H borylation where significant proton transfer character exists in the transition state.

Getting the sterics just right: a five-coordinate iridium trisboryl complex that reacts with C-H bonds at room temperature.

Five-coordinate boryl complexes relevant to Ir mediated C-H borylations have been synthesized, providing a glimpse of the most fundamental step in the catalytic cycle for the first time.

Direct synthesis of mesostructured lamellar molybdenum disulfides using a molten neutral n-alkylamine as the solvent and template.

A series of novel mesostructured lamellar molybdenum disulfides with the d spacings from 17 to 30 A can be prepared by the reaction of Mo(CO)6 with elemental sulfur using a molten n-alkylamine as the solvent as well as the template at 140 degrees C. Such intercalated phases can be transformed into mesoporous molybdenum disulfides by slow thermal treatments at 200 degrees C.