In combustion, enols can undergo keto-enol tautomerizations, which are intermediate steps in the formation of pollutant species. this work, we performed a theoretical kinetic study step-wise propen-2-ol tautomerization catalyzed by hydrogen and hydroperoxyl radicals. Ab initio calculations at CCSD(T)/aug-cc-pVTZ//M06-2X/cc-pVTZ level were run, rate constants calculated using multistructural tor...

A five-step mechanism is proposed for the NO -induced deamination of cytosine. It has been investigated using DFT calculations, including both explicit water molecules and a bulk solvent model to mimic an aqueous environment. According to this mechanism, cytosine first undergoes tautomerization with the assistance of a water molecule from the bulk. A NO(+) cation produced by the autooxidation o...

DFT calculations were conducted to pursue deeper understandings on the mechanism and the explicit role of trace water in the DBU-catalyzed β-amination of NBS to chalcone. Being different from previously proposed by Liang et al., a cooperative participation of both DBU and water is noticed in the preferred mechanism. The preferential mechanistic scenario assisted by water undergoes three major s...

5,15-Unsymmetrically disubstituted and beta-unsubstituted porphyrins such as 5-R, 15-(3,5-dimethoxyphenyl) porphyrins [where R=2-benzyloxy-1-naphthyl (1), 2-(2-naphthylmethoxy)-1-naphthyl (2), anthryl (3), or 2,4,6-triphenylphenyl (4)] and 5-(2-benzyloxy-1-naphthyl), 10,15,20-tri(3,5-dimethoxyphenyl) porphyrin (1') were synthesized and studied by (1)H-NMR spectroscopy. At room temperature, 1, 2...

The structures and relative stabilities of the complexes formed by uracil and its sulfur derivatives, namely, 2-thio-, 4-thio, and 2,4-dithio-uracil when interacting with Ca(2+) in the gas phase have been analyzed by means of density functional theory (DFT) calculations carried out at the B3LYP/6-311++G(3df,2p)//B3LYP/6-31+G(d,p) level. For uracil and 2,4-dithiouracil, where the two basic sites...

Femtosecond transient absorption anisotropy studies have been performed for two porphycenes of different symmetry. In 2,7,12,17-tetraphenylporphycene, the chemical identity of two trans forms implies a change in the S(0)-S(1) transition-moment direction upon tautomerization. Exploiting this phenomenon, the rates of double hydrogen transfer in both the S(0) and S(1) states (1.4×10(12)  s(-1) and...