Because of the difference in substitution position, compounds 1,2bis[2-(9-anthracenyl)vinyl]benzene (1,2-BAVB), 1,3-bis[2-(9-anthracenyl)vinyl]benzene (1,3-BAVB), and 1,4-bis[2-(9-anthracenyl)vinyl]benzene (1,4-BAVB) display different crystal packing and optical property. 1,4-BAVB molecules pack into zigzag structure. The π-electrons are averagely distributed on the whole backbone though the molecule adopts a twisted structure. Compounds 1,2-BAVB and 1,3-BAVB have a column-like structure, and the π-electrons are mainly confined on the anthracene units. Obvious π•••π interactions exist in the aggregates of 1,3-BAVB and 1,4-BAVB. The crystal packing and electronic structure exert dramatic influence on the photophysical property. Compound 1,4-BAVB is hardly emissive. Compound 1,3-BAVB is highly emissive in solution but quenched in the solid state. However, compound 1,2-BAVB displays an aggregation-induced emission behavior and an excimer-related fluorescence in solution. The relationship between the aggregate packing, electronic structure, and photophysical property was studied.

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Hollow nanomaterials provide abundant reaction sites and facilitate tolerance for volume changes during the charging- discharging process, which is potential candidates for alkaline ion storage. In this work, hollow CuO...

Quantum dot (QD) sensitization of TiO 2 is a powerful method to improve its performance as a photoanode material in solar energy conversion. The efficiency of sensitization depends strongly on the rate of interfacial electron transfer (ET) from the QDs to TiO 2 . To understand the key factors affecting the ET, arene-substituted (ortho, meta, and para) bifunctional linkers with single or double aromatic rings were employed to link CdSe QDs to TiO 2 and control the strength of their interaction as well as the rate of interfacial ET. Interestingly, the para-substituted aromatic linker, 4-mercaptobenzoic acid (4MBA) with the longest distance between the carboxyl and thiol groups, shows the best photoelectrochemical (PEC) performance, when compared to those of ortho-subtituted (2-mercaptobenzoic acid, 2MBA) and meta-substituted (3-mercaptobenzoic acid, 3MBA) aromatic linkers. Two other bifunctional linkers with double aromatic rings, 4′-mercapto-[1,1′-biphenyl]-4-carboxylic acid (4M1B4A) and 6-mercapto-2-naphthioc acid (6M2NA), were also studied for comparison. Ultrafast transient absorption (TA) spectroscopy was used to study the exciton dynamics in CdSe QDs and determine the interfacial ET rate constant (k ET ). The k ET results are consistent with the trend of PEC measurements in that 4MBA shows the highest k ET . To gain further insight into the ET mechanism, we performed density functional theory (DFT) calculations to examine the intrinsic properties of the linkers. The results revealed that the favorable wave function distribution of the molecular orbitals of 4MBA and 4M1B4A are responsible for the higher interfacial ET rate and PEC performance due to better interfacial coupling, a factor that dominates over distance. The present study provides important new insight into the mechanism of interfacial ET using aromatic bifunctional linkers, which is useful in designing QD sensitized semiconductor metal oxide nanostructures for applications including photovoltaics and solar fuel generation.