The emission transition dipole moments of single-molecule free-base phthalocyanines at an air/glass interface were visualized using defocused wide-field fluorescence microscopy at a temporal resolution of 100-200 ms. Isolated molecules showed slow proton tautomerization, which is consistent with previous theoretical calculations in the gas phase, which predicted large activation energies.

dacarbazine (dtic) is a synthetic chemical antitumor agent which is used to treat malignant melanoma and hodgkin’s disease. dtic is a prodrug which is converted to an active form undergoing demethylation by liver enzymes. the active form prevents the progress of disease via alkylation of dna strand. in the structure of this drug, the imidazole ring, a triazen chain and carboxamide group exist. ...

Tautomerization of amino acids between the neutral form (NF) and the zwitterionic form (ZW) in water has been extensively studied, often using glycine as a model to understand this fundamental process. In spite of many advanced studies, the tautomerization reaction remains poorly understood because of the intrinsic complexities of the system, including multiple accessible reaction pathways, cha...

An efficient one-pot three-component protocol for the synthesis of novel tetrahydrobenzofuran-chromone conjugates using 3-formylchromones and 1,3-cyclohexandiones in presence a variety alkyl or aryl isocyanides was developed. The reaction sequence consists an initial Knoevenagel condensation aromatic aldehydes with 1,3-cyclohexandione derivatives, followed by [4 + 1] cycloaddition isocyanides, ...

palladium (ii) coordination complexes catalyze the reaction of alcohols with ketones to yield ethers. during the catalytic cycle, the alcohol adds selectively to the β-carbon (anti-markovnikov). in this work, mechanism and kinetics for the reaction of methanol with methyl vinyl ketone (mvk), being catalyzed by pd, has been theoretically investigated in detail. using quantum mechanical approach,...