A highly selective fluorescent probe for a protein tyrosine phosphatase (PTP) was designed by a simple phosphorylation of the 2-(2'-hydroxyphenyl)benzothiazole (HBT) chromophore: upon selective enzymatic hydrolysis, an excited-state intramolecular proton transfer (ESIPT) occurs, resulting in a large Stokes shift.

Intramolecular proton transfer in rifampicin (1) and its analogues 2-9 with the formation of zwitterions has been indicated by multinuclear NMR and crystallographic studies. Biological tests of 1-9 in combination with the analysis of ligand-protein interactions have revealed the relationship between the protonation site and extremely high antibacterial activity.

The cascade rearrangement of chiral enediynes 1c-e, involving successively 1,3-proton shift, Saito-Myers cyclization, 1,5-hydrogen atom transfer, and intramolecular coupling of the resulting biradical, proceeded at 80 °C to form tri- and tetracyclic heterocycles possessing a quaternary stereogenic center with a very high level of memory of chirality.

Boronic acids are versatile reagents for the chemical synthesis of organic molecules. They and other boron-containing compounds can be detected readily by the interruption of the excited-state intramolecular proton transfer (ESIPT) of 10-hydroxybenzo[h]quinolone. This method is highly sensitive and selective, and useful for monitoring synthetic reactions and detecting boron-containing compounds...

A straightforward procedure based on the formation of intramolecular hydrogen bonds to impart selectivity in the preparation of multi-functionalized porphyrins has been developed. To illustrate the concept, the synthesis of a biomimetic artificial photosynthetic model able to undergo electron and proton transfer reactions upon irradiation is reported.

The NMR spectra of azo dyes, 5-arylazobarbituric (5a-g), 5-arylazo-1,3-dimethylbarbituric(6a-g) and 5-arylazothiobarbituric acids (7a-g) were studied in DMSO-d6 in differentconcentrations. An intramolecular hydrogen bond was observed and indicating that thehydrazone forms is mostly predominant. The peak of the hydrazone proton was severelybroadened and its chemical shift appeared at down field ...

A bis(benzoxazole) derivative with metal-chelating ligand (DPA), Zinhbo-1, exhibits a large fluorescence turn-on effect (up to 10-fold) upon zinc-binding. The metal chelation enables excited state intramolecular proton transfer (ESIPT), giving an additional emission band in the near-IR region (approximately 710 nm) with a large Stokes shift (ca. 230 nm).

The mechanism of the title reaction is found to consist of three steps by DFT calculations: (1) N(2) dissociation, (2) intramolecular Ag-carbene addition, and (3) proton transfer. The N(2) dissociation is turnover determining. The product 3-alkylideneoxindole is favored in tautomerization with 3-acetyl-2-hydroxyindole.

In this letter, we propose a novel, ultrafast, efficient molecular switch whose switching mechanism involves the electric field-driven intramolecular proton transfer. By means of ab initio quantum chemical calculations and on-the-fly dynamics simulations, we examine the switching performance of an isolated salicylidene aniline molecule and analyze the perspectives of its possible use as an elec...

In this paper, density functional theory (DFT) and time-dependent DFT (TDDFT) methods were used to investigate substituent effects excited-state intramolecular double-proton transfer (ESIDPT) in 1, 3-bis (2-pyridylimino)-4, 7-dihydroxyisoindole (BPI–OH) its derivatives. The results of a systematic study the electron-withdrawing groups (F, Cl Br) on adjacent sites benzene ring regulate photophys...