Theoretical study on optimizing dipeptidomimetic isocyanonaphthalene chemosensor and the fluorescence mechanism for detecting Hg.

The excited (S) state charge distribution characteristics and fluorescence mechanism of fluorescence probes benzyl (6-cyano-2-naphthoyl)-L-valinate (NPI) and benzyl (6-amino-2-naphthoyl)-L-valinate (NPA) have been discussed using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). Further analysis by constructing a torsional potential energy curve (PEC) shows that a well-defined minimum energy conformation is observed when the C-C single bond between the valine benzyl ester and naphthalene ring in NPI rotates. For NPA, the most stable conformation is the naphthalene ring conformation with dihedral angle NCCC of -30.

Theoretical investigation on regulating photophysical properties and proton transfer behavior by electronegativity for near-infrared emitting styryl dyes.

Our main focus is to explore the atomic electronegativity-dependent photoinduced behavior of styryl derivatives (HBO, HBS, and HBSe). The results of structural parameter calculation by the DFT method show that the intramolecular hydrogen bonds of normal and tautomer form are strengthened and weakened, respectively, in an excited state (S), which is conducive to the excited intramolecular proton transfer (ESIPT) process. The enhancement of excited hydrogen bond is beneficial to the ESIPT process from the aspects of infrared vibration frequency (IR), Mulliken's charge analysis, and density gradient reduction (RDG).

Theoretical Study of Effects of Anchoring Groups on Photovoltaic Properties of a Triarylamine-Based p-Type Sensitizer.

The effects of anchoring groups on triarylamine-based p-type dyes were studied by substituting the strong electron-withdrawing carboxyl group with the weak electron-withdrawing pyridyl and the electron-rich catechol groups. Judged by the index , the charge separation would be improved greatly when the carboxyl group of is replaced by the pyridyl or catechol groups. Although carboxyl as an anchoring group lowers the HOMO energy and facilitates the hole injection in comparison with pyridyl and catechol groups, the weak electron-withdrawing pyridyl and the electron-rich catechol groups facilitate the charge separation.

Design of high performance p-type sensitizers with pyridinium derivatives as the acceptor by theoretical calculations.

Based on triphenylamine as an electron donor and thiophene as a π-linker, Series P and A p-type sensitizers were designed to investigate the effects of the different acceptors on the properties of the sensitizers. The optimized molecular structures, electronic and optical properties were investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT). The results showed that the properties of the dyes can be tuned by the introduction of the different electron-withdrawing groups to the N atom in the pyridinium acceptor.

Effect of Nitrogen Cation as "Electron Trap" at π-Linker on Properties for -Type Photosensitizers: DFT Study.

On the basis of thieno(3,2-)thiophene and dithieno[3,2-:2',3'-]thiophene ( and moieties) as π-linker, the , and series dyes were designed to investigate the effect of the introducing N as an "electron trap" into and on the properties of the dyes. The optimized structures, electronic and optical properties were investigated by the density functional theory (DFT) and time-dependent DFT (TD-DFT). The results show that the properties of the dyes are sensitive to the N position in π-linkers.

Theoretical study on the structural, vibrational, and thermodynamic properties of the (Br₂GaN₃)n (n = 1-4) clusters.

The molecular geometries, vibrational properties, and thermodynamic properties of the clusters (Br(2)GaN(3))( n )(n = 1-4) were studied at the B3LYP/6-311+G* level. The optimized clusters (Br(2)GaN(3))( n )(n = 2-4) were all found to possess a cyclic structure consisting of Ga atoms bridged by the α-nitrogen of the azide groups. A discussion of the relationships between the geometrical parameters and the degree of oligomerization n is provided.

Strain energies of cubane derivatives with different substituent groups.

Homodesmotic reaction and isodesmotic reaction were designed for the computation of strain energies (SE) for a series of cubane derivatives. Total energies of the optimized geometric structures at the DFT-B3LYP/6-31G* level were used to derive the SE. The SE value of cubane is 169.