Theoretical insight on the charge transport properties: The formation of "head-to-tail" and "head-to-head" stacking of asymmetric aryl anthracene derivatives.

Organic semiconductors (OSCs) are widely used in flexible display, renewable energy, and biosensors, owing to their unique solid-state physical and optoelectronic properties. Among the abundant crystal library of OSCs, asymmetric aryl anthracene derivatives have irreplaceable advantages due to the interplay between their distinct π-conjugated geometry and molecular stacking as well as efficient light emission and charge transport properties that can be simultaneously utilized. However, the poor crystal stacking patterns of most asymmetric molecules limit their utility as excellent OSCs. Thus, it is crucial to clarify the structural features that enable the extremely ordered stacking and favorable electronic structure of asymmetric anthracene derivatives to become high-performance OSCs. This contribution investigates the charge transport properties of a series of asymmetric aryl anthracene derivatives to reveal the modulation factors of the molecular stacking modes and to explore the structural factors, which are beneficial to charge transport. The analysis demonstrated that the vinyl-linker facilitated the injection of hole carriers, and the alkynyl-linker effectively reduces the reorganization energy. Importantly, the linear polarizability and permanent dipole moment of a single molecule play a vital regulation to molecular stacking modes and the transfer integral of the dimer. The "head-to-head stacking" motif shows a compact stacking pattern and the maximum 2D anisotropic mobility more than 10 cm2 V-1 s-1. These findings sharpen our understanding of the charge transport properties in asymmetric organic semiconductors and are essential for developing a diverse range of high-performance OSC materials.

Comparison of Antioxidant Capacity and Muscle Amino Acid and Fatty Acid Composition of Nervous and Calm Hu Sheep.

This study determined the effect of temperament on antioxidant capacity and the relationship between antioxidant capacity and the contents of amino acids (AA) and fatty acids (FA) in muscle of Hu sheep. Organ and muscle samples of five calm and five nervous Hu sheep were collected to determine the antioxidant capacity and the contents of AA and FA in muscle tissue. The concentrations of malondialdehyde (MDA) and superoxide excretion enzyme (SOD) in muscle and intestinal tissue of calm Hu sheep were lower than those of nervous Hu sheep (p < 0.01), and the activity of glutathione peroxidase (GSH-Px) in liver of calm Hu sheep was significantly higher than that of nervous Hu sheep (p = 0.050). The content of AA of calm Hu sheep was higher than that of nervous Hu sheep, especially the content of reductive amino acids, which was significantly higher than that of nervous Hu sheep (p = 0.029). Fatty acid content of nervous Hu sheep was higher than that of calm type, and saturated fatty acid content was significantly higher than that of calm type (p = 0.001). The SOD content in muscle tissue was positively correlated with the contents of aspartic acid (Asp), alanine (Ala) and lysine (Lys). Catalase (CAT) activity was positively correlated with Ala content. There was a significant positive correlation between total antioxidants (T-AOC) and glutamate (Glu) (p < 0.05). MDA concentration was positively correlated with lauric acid (C12:0), triseconic acid (C13:0), myristic acid (C14:0) content (p < 0.01), and ginkgo acid (C15:0) content. The total antioxidants (T-AOC) was negatively correlated with stearic acid (C18:0) (p < 0.05). Our conclusion is that the antioxidant capacity of calm Hu sheep is superior to that of nervous Hu sheep, which may be due to the higher AA (especially reductive amino acids (Arg, Lys, Ala and Glu)) content in the muscle and the lower FA (especially SFA) content, which improve the antioxidant capacity of the organism and allow for further exploration of the mechanisms by which animal temperament affects antioxidant performance.