For inorganic semiconductors crystalline order leads to a band structure which gives rise to drastic differences to the disordered material. An example is the presence of an indirect band gap. For organic semiconductors such effects are typically not considered, since the bands are normally flat, and the band-gap therefore is direct. Herein we show results from electronic structure calculations demonstrating that ordered arrays of porphyrins reveal a small dispersion of occupied and unoccupied bands leading to the formation of a small indirect band gap. We demonstrate herein that such ordered structures can be fabricated by liquid-phase epitaxy and that the corresponding crystalline organic semiconductors exhibit superior photophysical properties, including large charge-carrier mobility and an unusually large charge-carrier generation efficiency. We have fabricated a prototype organic photovoltaic device based on this novel material exhibiting a remarkable efficiency.

Conjugated microporous polymers (CMPs) have attracted much interest due to their intrinsic porosity, outstanding stability, and high variability. However, the processing of these materials for membrane application has been limited due to their insoluble nature when synthesized as bulk material. Here we report the synthesis of freestanding CMP-nanomembranes via layer-by-layer growth of a "click" based conjugated microporous polymer on a sacrificial substrate. After dissolution of the substrate the CMPnanomembrane can be transferred to porous substrates and continuously cover holes of up to 50 μm diameter. The CMPnanomembranes appear defect-free as inferred from high selectivity values obtained from gas permeation experiments and from electrochemical investigation in the presence of ferrocene. The presented synthesis method represents a versatile strategy to incorporate CMP materials in functional devices for membrane separation, catalysis, or organic electronics. C onjugated microporous polymers (CMP) are a class of microporous solids which have recently attracted wide interest due to their large surface areas, low densities, and the possibility to incorporate different kinds of functional groups in a modular fashion. 1 In contrast to related metal organic frameworks (MOF) 2−5 or covalent organic frameworks (COF) 6,7 which are formed through reversible reactions, CMPs are formed through high yielding irreversible reactions of rigid building blocks. The resulting CMP materials are amorphous and at the same time often show narrow pore size distribution. 8 The exceptional thermal and chemical stability goes well beyond that of MOFs and COFs and makes this class of porous materials particularly appealing for practical applications such as gas storage, catalysis, and molecular separation. 9,10 Among the numerous synthetic routes used in the past, click reaction chemistry has played a special role as a result of its ease of operation. The high purity and readily accessible products of click chemistry are particularly attractive to produce CMP materials. 11 Among the large variety of CMP applications, two-dimensional nanomembranes with a thickness below 10 nm exhibiting tunable pore sizes that can act as molecular sieves have a particularly large potential, since they are predicted to be ideal separation membranes with many advantages over bulk membranes. 12,13 However, the inert nature of most CMP materials causes severe, intrinsic challenges in their processing to yield large scale membranes. Indeed, only branched "soluble conjugated microporous polymers" (SCMPs) 14 and linear conjugated polymers of intrinsic microporosity (C-PIMs) 15 can be processed from solution. Usually CMPs are, in contrast to most polymers, not soluble in organic solvents, 1 and as a result, common processing techniques to fabricate polymer films from a solution such as spin coating cannot be applied.Considering the recent success in using layer-by-layer or quasi-epitaxial approaches for the fabrication of thin MOFlayers (SURMOFs) 16,17 we fabric...

A structure-guided hybridization approach using two privileged substructures gave instant access to a new series of tankyrase inhibitors. The identified inhibitor 16 displays high target affinity on tankyrase 1 and 2 with biochemical and cellular IC values of 29 nM, 6.3 nM and 19 nM, respectively, and high selectivity toward other poly (ADP-ribose) polymerase enzymes. The identified inhibitor shows a favorable in vitro ADME profile as well as good oral bioavailability in mice, rats, and dogs. Critical for the approach was the utilization of an appropriate linker between 1,2,4-triazole and benzimidazolone moieties, whereby a cyclobutyl linker displayed superior affinity compared to a cyclohexane and phenyl linker.

Battling metastasis through inhibition of cell motility is considered a promising approach to support cancer therapies. In this context, Ena/VASP-depending signaling pathways, in particular interactions with their EVH1 domains, are promising targets for pharmaceutical intervention. However, protein–protein interactions involving proline-rich segments are notoriously difficult to address by small molecules. Hence, structure-based design efforts in combination with the chemical synthesis of additional molecular entities are required. Building on a previously developed nonpeptidic micromolar inhibitor, we determined 22 crystal structures of ENAH EVH1 in complex with inhibitors and rationally extended our library of conformationally defined proline-derived modules (ProMs) to succeed in developing a nanomolar inhibitor (Kd=120 nM,MW=734Da). In contrast to the previous inhibitor, the optimized compounds reduced extravasation of invasive breast cancer cells in a zebrafish model. This study represents an example of successful, structure-guided development of low molecular weight inhibitors specifically and selectively addressing a proline-rich sequence-recognizing domain that is characterized by a shallow epitope lacking defined binding pockets. The evolved high-affinity inhibitor may now serve as a tool in validating the basic therapeutic concept, i.e., the suppression of cancer metastasis by inhibiting a crucial protein–protein interaction involved in actin filament processing and cell migration.

Coupled up: A new general palladium‐catalyzed procedure for the cross‐coupling of aryl and heteroaryl tosylates is described. This highly versatile and efficient process can be used for the synthesis of a wide variety of functionalized alkynes (see scheme).