A single crystal of N,N'-bis(4-methoxybenzyl)perylene-3,4,9,10-bis(dicarboximide) (mb-PBI) that possesses novel magic-angle stacking (M-type stacking) and strong intermolecular π-π interaction is achieved by physical vapor transport (PVT), which shows attractive optoelectronic functions such as efficient NIR emission and high electron mobility. In this special M-type staking, the strong Frenkel/CT mixing state promotes fluorescence and, importantly, the elimination of long-distance Förster resonance energy transfer enables the minimization of the possible fluorescence quenching, which ensure the highly efficient emission. Moreover, the strong π-π interaction elongates the "supramolecular conjugation" to reduce the energy gap and also benefits the electron mobility of the crystal. The experimental results clearly indicate that M-type staking is a novel approach to optimize the optoelectronic functions of organic semiconducting materials.

The development of asymmetric methodologies for the synthesis of chiral indoles has been a long-standing project in organic synthesis. Indole skeletons are heterocyclic systems and are present in numerous alkaloid products, pharmaceuticals, and agrochemicals.[1] Cyclopenta [b]indole skeletons can be found in a number of indole alkaloids, [2] but have not been extensively reported. Compounds that contain such a unit exhibit a wide range of biological activities.[3] For example, 2-aminocyclopenta[b]indoles, [4a] cyclopenta [b]indole-substituted acetic acids, [4b] and a series of yuehchukene analogues [5] have been successfully synthesized and used in medicinal chemistry. Although a number of methods have been developed for the synthesis of cyclopenta [b]indoles, [6] only few of them are asymmetric and especially catalytic asymmetric methods. [7] To the best of our knowledge, there is only one example of the synthesis of chiral cyclopenta [b]indoles by asymmetric catalysis with acceptable enantioselectivities.[8]The development of efficient methods for the construction of cyclopenta [b]indole units is therefore highly desirable. As a continuation of the work of our research group toward the catalytic asymmetric a-alkylation of carbonyl compounds, [9] we rationally designed a one-pot [10] three-step reaction, which consisted of the a-alkylation of an aldehyde, catalyzed by a primary-amine-substituted thiourea, [11] and two consecutive Brønsted acid catalyzed Friedel-Crafts reactions of an indole, [12] to construct chiral polysubstituted cyclopenta [b]indoles (Scheme 1). Herein, we report these consecutive organocatalyzed reactions, which gave structurally diverse cyclopenta [b]indoles in high yields (up to 85 %), and with excellent diastereoselectivities (up to > 99:1) and enantioselectivities (up to 99 % ee).The reactions shown in Scheme 1 were realized in three stages. In the first stage, we examined the a-alkylation of isobutylaldehyde 4 a with 3-indolylmethanol 3 a (step 1) under catalysis by chiral amines 1 and acids 2. Although several methods for the asymmetric amine-based catalysis have been used in similar a-alkylation reactions of aldehydes with diarylmethanol compounds, [11] to date a,a-disubstituted aldehydes have not been used as donors. For the method reported herein, a,a-disubstituted aldehydes were very important precursors because they could produce aldehydes 5 (Scheme 1), which could not be enolated during the following Friedel-Crafts alkylations; thus, there were fewer side reactions in this method. Several amine-based catalysts were investigated in the a-alkylation reaction of aldehyde 4 a.

Catalytic Asymmetric Direct -Alkylation of Amino Esters by Aldehydes via Imine Activation. -Various differently substituted tryptophan derivatives are prepared with up to 98% enantiomeric excess.

PSS HTL. Incorporation of V2O5·nH2O as HTL in the polymer solar cell was found to enhance the crystallinity of the active layer, electron-blocking at the anode and the light-harvest in the wavelength range of 400-550 nm in the cell. V2O5·nH2O HTL improves the charge generation and collection and suppress the charge recombination within the PBDSe-DT2PyT:PC71BM solar cell, leading to a simultaneous enhancement in Voc, Jsc, and FF. The V2O5·nH2O HTL proposed in this work is envisioned to be of great potential to fabricate highly efficient PSCs with low-cost and massive production.

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