A fluorophore's electron-deficiency does matter in designing high-performance near-infrared fluorescent probes.

The applications of most fluorescent probes available for Glutathione -Transferases (GSTs), including which we developed recently based on 1,8-naphthalimide (), are limited by their short emission wavelengths due to insufficient penetration. To realize imaging at a deeper depth, near-infrared (NIR) fluorescent probes are required. Here we report for the first time the designing of NIR fluorescent probes for GSTs by employing the NIR fluorophore which possesses a higher brightness, hydrophilicity and electron-deficiency relative to .

Quantitative prediction of charge mobilities of π-stacked systems by first-principles simulation.

This protocol is intended to provide chemists and physicists with a tool for predicting the charge carrier mobilities of π-stacked systems such as organic semiconductors and the DNA double helix. An experimentally determined crystal structure is required as a starting point. The simulation involves the following operations: (i) searching the crystal structure; (ii) selecting molecular monomers and dimers from the crystal structure; (iii) using density function theory (DFT) calculations to determine electronic coupling for dimers; (iv) using DFT calculations to determine self-reorganization energy of monomers; and (v) using a numerical calculation to determine the charge carrier mobility.

Electronic structure and microscopic charge-transport properties of a new-type diketopyrrolopyrrole-based material.

Recently, diketopyrrolopyrrole (DPP)-based materials have attracted much interest due to their promising performance as a subunit in organic field effect transistors. Using density functional theory and charge-transport models, we investigated the electronic structure and microscopic charge transport properties of the cyanated bithiophene-functionalized DPP molecule (compound 1). First, we analyzed in detail the partition of the total relaxation (polaron) energy into the contributions from each vibrational mode and the influence of bond-parameter variations on the local electron-vibration coupling of compound 1, which well explains the effects of different functional groups on internal reorganization energy (λ).

First-principles investigation of the electronic and conducting properties of oligothienoacenes and their derivatives.

Herein, we calculated reorganization energies, vertical ionization energies, electron affinities, and HOMO-LUMO gaps of fused thiophenes and their derivatives, and analyzed the influence of different substituents on their electronic properties. Furthermore, we simulated the angular resolution anisotropic mobility for both electron- and hole-transport, based on quantum-chemical calculations combined with the Marcus-Hush electron-transfer theory. We showed that: 1) styrene-group substitution can effectively elevate the HOMO energy level and lower the LUMO energy level, and therefore lower both the hole- and electron-injection barriers; and 2) chemical oxidation of the thiophene ring can significantly improve the semiconductor properties of the fused oligothiophenes through a decrease of the injection barrier and an increase in the charge-transfer mobility for electrons but without lowering their hole-transfer mobilities, which suggests that it may be a promising way to convert p-type semiconductors into ambipolar or n-type semiconductor materials.

Simulation of hole mobility in α-oligofuran crystals.

We investigated oligofuran (nF) (n=3, 4, 6) heterocyclic oligomers as p-type organic semiconductor materials, based on quantum chemistry calculations combined with the Marcus-Hush electron transfer theory. It was found that 6F single crystal, with a structure similar to that of 6T, possesses high hole-transfer mobility, which is nearly 17 times larger than that of 6T single crystal. In addtion, the ionization potential (IP) value of 6F is about 5.

Revealing quantitative structure-activity relationships of transport properties in acene and acene derivative organic materials.

The intermolecular electronic coupling (transfer integral) and the intramolecular vibronic coupling (reorganization energy) are key parameters determining the transport properties of organic electronic materials. Using quantum mechanism calculations, we revealed the correlation between the reorganization energies and the partial charge difference values on the conjugated acene backbone, which can be used to evaluate the reorganization energies for acene and acene derivative systems with the same conjugated backbone but different substitutional groups. We used rigorous quantitative functions to investigate the electronic coupling oscillation behavior in slipped-cofacial stacking acene and acene derivative molecules, and revealed characteristic parameters in the electronic coupling oscillation.

First-principles investigation of anistropic hole mobilities in organic semiconductors.

We report a simple first-principles-based simulation model (combining quantum mechanics with Marcus-Hush theory) that provides the quantitative structural relationships between angular resolution anisotropic hole mobility and molecular structures and packing. We validate that this model correctly predicts the anisotropic hole mobilities of ruberene, pentacene, tetracene, 5,11-dichlorotetracene (DCT), and hexathiapentacene (HTP), leading to results in good agreement with experiment.

Improved organic hydrogen carriers with superior thermodynamic properties.

By the incorporation of N atoms into naphthalene, we present a theoretical investigation to seek for improved organic hydrogen carriers with an explicit guideline, the release of H2 is found to be greatly favored thermodynamically and the corresponding cycloalkanes possess high hydrogen storage capacity, this offers extensive candidates for practical applications of the promising hydrogen energy.