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This corrects the article DOI: 10.1038/nchembio.2548.

Two-dimensional infrared (2D IR) spectroscopy, infrared pump–infrared probe spectroscopy, and density functional theory calculations were used to study vibrational relaxation by ring and carbonyl stretching modes in a series of methylated xanthine derivatives in acetonitrile and deuterium oxide (heavy water). Isotropic signals from the excited symmetric and asymmetric carbonyl stretch modes decay biexponentially in both solvents. Coherent energy transfer between the symmetric and asymmetric carbonyl stretching modes gives rise to a quantum beat in the time-dependent anisotropy signals. The damping time of the coherent oscillation agrees with the fast decay component of the carbonyl bleach recovery signals, indicating that this time constant reflects intramolecular vibrational redistribution (IVR) to other solute modes. Despite their similar frequencies, the excited ring modes decay monoexponentially with a time constant that matches the slow decay component of the carbonyl modes. The slow decay times, which are faster in heavy water than in acetonitrile, approximately match the ones observed in previous UV pump–IR probe measurements on the same compounds. The slow component is assigned to intermolecular energy transfer to solvent bath modes from low-frequency solute modes, which are populated by IVR and are anharmonically coupled to the carbonyl and ring stretch modes. 2D IR measurements indicate that the carbonyl stretching modes are weakly coupled to the delocalized ring modes, resulting in slow exchange that cannot explain the common solvent-dependence. IVR is suggested to occur at different rates for the carbonyl vs ring modes due to differences in mode-specific couplings and not to differences in the density of accessible states. [ABSTRACT FROM AUTHOR]

A catalytic and highly enantioselective dearomative alkynylation of chromanones has been discovered that enables the construction of biologically relevant tertiary ether stereogenic centers. This methodology is robust, accommodating a variety of alkynes and chromanones. More than 40 substrates tested gave rise to >90% ee. Computational studies have indicated that the optimal indanyl ligand identified for most cases likely affords a network of supportive, non-covalent interactions that drive the enantioselective nature of the reaction. [ABSTRACT FROM AUTHOR]

Report is presented on a nano second time resolved resonance Raman (T[R.sup.3]) study of reactions in room temperature solutions. The structures, properties and chemical reactivity of the dimer species observed in the (T[R.sup.3]) spectra are discussed.

The use of template-directed synthesis to obtain a new family of diastereoselective bowl-shaped molecules is demonstrated. They comprise a semirigid frame and adjustable size cavity capable of coordinating transition metal cations.

The petrochemistry of 2-naphthyl azide studies by employing ultrafast time-resolved spectroscopy and quantum chemical calculations is reported. The singlet nitrene intermediate with a barrier of approximately 5 kcal/mol for [N.sub.2] extrusion in the reaction is observed to have the shortest lifetime.

Density functional theory (DFT) calculations and stopped-flow kinetics are used for predicting the reactivity of functionalized spin traps with superoxide radical anion. The results have shown that using an N-monoalkylsubstituted amine or an ester as attached groups on the nitrone is ideal in molecular tethering for improved spin-trapping properties and also for improved radical detection at the site of superoxide formation.

The cytochrome P450 acts as an oxidant of halogenated benzene derivatives mediated by Compound I. These reactions in which there is selective elimination of halogen atoms can be utilized to tackle the environmental pollution caused by the aromatic halogen derivatives.

The experimental laser flash photolysis and product studies along with molecular modeling shows that azide undergoes both [alpha]-cleavage and energy transfer to form benzoyl radical and triplet alkylnitrene while azide selectively forms triplet alkylnitrene. Based on the results it is concluded that benzoyl radicals could be formed from nitrenes and nitrene also undergo [alpha]-photocleavage to form benzoyl radicals and iminyl radicals.

The reactions between [Mo.sub.2][([O.sub.2]C[super t]Bu).sub.4] and each of terephthalic acid and 4,4'-azodibenzoic acid have produced the compounds [[[Mo.sub.2][([O.sub.2]C[super t]Bu).sub.3]].sub.2]([mu]-[O.sub.2]C[C.sub.6][H.sub.4]C[O.sub.2]) and [[[Mo.sub.2][([O.sub.2]C[super t]Bu).sub.3]].sub.2]([mu]-[O.sub.2]C[C.sub.6][H.sub.4][N.sub.2][C.sub.6][H.sub.4]C[O.sub.2]), which are characterized by spectroscopic and electrochemical methods. The results have shown that the terephthalate bridge is more effective in electronic coupling between [Mo.sub.2] quadruply bonded centers than is the longer 4,4'-azodibenzoate.