To shed light on intramolecular charge-transfer phenomena in 1,2,3-triazole-linked materials, a series of 1,2,3-triazole-linked push-pull chromophores were prepared and studied experimentally and computationally. Investigated modifications include variation of donor and/or acceptor strength and linker moiety as well as regioisomers. Photophysical characterization of intramolecular charge-transf...

The divergent behaviour of 3-alkynylindole-2-carboxamides, under palladium catalysed conditions and phase-transfer catalytic conditions, is described. Thus, palladium catalysed intramolecular C-N and C-C bond formation in a single step by C-H activation involving 3-alkynylindole-2-carboxamides and leading to pyrrolodiindolones in high yields is developed. In contrast, using the same precursors,...

Switching of intramolecular energy transfer is a challenging subject [ l-3 1. The problem is: is it possible to use a photochromic molecule F as central part of a supermolecule D-F-A to allow or to hinder energy transfer from D (donor) to A (acceptor) by switching F with light of the appropriate wavelength from one of its photochromic configurations into the other one and back? Promising candid...

We report the synthesis and photophysical investigation of a series of rotaxanes in which the physical confinement of the donor and acceptor (DA) pair leads, in some cases, to emissive exciplexes. As a comparison, we examined the photoinduced charge-transfer processes in the same DA mixtures under intermolecular conditions. The interlocked configuration of the rotaxane facilitates pi orbital ov...

A series of Schiff bases, salicylideneaniline derivatives 1-4, was synthesized under mild conditions and characterized by 1H NMR, HRMS, UV-Vis and fluorescence spectra, and single-crystal X-ray diffraction. In solid and aprotic solvents 1-4 exist mainly as E conformers that possess an intramolecular six-membered-ring hydrogen bond. A weak intramolecular C-H···F hydrogen bond is also observed in...

We report the construction of a synthetic flavo-heme protein that incorporates two major physiological activities of flavoproteins: light activation of flavin analogous to DNA photolyase and rapid intramolecular electron transfer between the flavin and heme cofactors as in several oxidoreductases. The functional tetra-alpha-helix protein comprises two 62-aa helix-loop-helix subunits. Each subun...

We investigated the mechanism of intramolecular charge transfer and the following radiationless dynamics of the excited states of 1-aminoanthraquinone using steady state and time-resolved absorption spectroscopy combined with quantum chemical calculations. Following photoexcitation with 460 nm, conformational relaxation via twisting of the amino group, charge transfer and the intersystem crossi...

Two diazaporphyrin (DAP)-porphyrin hetero dimers, in β-meso and β-β configurations, were prepared to study their photoinduced intramolecular electron transfer properties. The two meso nitrogen atoms in the porphyrin ring of DAP change its redox potential, making DAP more easily reduced, compared to its porphyrin counterpart. A charge-transfer from porphyrin to DAP in both hetero dimers was veri...

In a previous study of a naproxen dyad in a pair of N-methylimidazoliummethyl menthylether-NTf(2) chiral ionic liquids (J. Phys. Chem. B 2008, 112, 7555), we observed that though intramolecular electron transfer was impeded, a consistent small stereodifferentiation in the fluorescence lifetime of the dyad was obtained. We proposed that this discrimination was purely electronic in nature and did...

Potential energy (PE) curves for the intramolecular proton transfer in the ground (GSIPT) and excited (ESIPT) states of 1-hydroxy-2naphthaldehyde (1H2NA) and 2-hydroxy-3-naphthaldehyde (2H3NA) were studied using DFT/B3LYP(6-31G) and TD-DFT/ B3LYP(6-31G) level of theory, respectively. Our calculations suggest the non-viability of ground state intramolecular proton transfer for both the compounds...