Design of High-Performance Organic Nonlinear Optical and Terahertz Crystals by Controlling the van der Waals Volume.

In the development of new organic crystals for nonlinear optical and terahertz (THz) applications, it is very challenging to achieve the essentially required non-centrosymmetric molecular arrangement. Moreover, the resulting crystal structure is mostly unpredictable due to highly dipolar molecular components with complex functional substituents. In this work, new organic salt crystals with top-level macroscopic optical nonlinearity by controlling the van der Waals volume (V ), rather than by trial and error, are logically designed.

Phonon-Suppressing Intermolecular Adhesives: Catechol-Based Broadband Organic THz Generators.

Solid-state molecular phonons play a crucial role in the performance of diverse photonic and optoelectronic devices. In this work, new organic terahertz (THz) generators based on a catechol group that acts as a phonon suppressing intermolecular adhesive are developed. The catechol group is widely used in mussel-inspired mechanical adhesive chemistry.

Copper-catalysed asymmetric reductive cross-coupling of prochiral alkenes.

Asymmetric construction of C(sp)-C(sp) bond with good stereocontrol of the two connecting carbon centres retaining all carbon or hydrogen substituents is a challenging target in transition metal catalysis. Transition metal-catalysed reductive coupling of unsaturated π-substrates is considered as a potent tool to expediently develop the molecular complexity with high atom efficiency. However, such an asymmetric and intermolecular process has yet to be developed fully.

Organic Broadband THz Generators Optimized for Efficient Near-Infrared Optical Pumping.

New organic THz generators are designed herein by molecular engineering of the refractive index, phonon mode, and spatial asymmetry. These benzothiazolium crystals simultaneously satisfy the crucial requirements for efficient THz wave generation, including having nonlinear optical chromophores with parallel alignment that provide large optical nonlinearity; good phase matching for enhancing the THz generation efficiency in the near-infrared region; strong intermolecular interactions that provide restraining THz self-absorption; high solubility that promotes good crystal growth ability; and a plate-like crystal morphology with excellent optical quality. Consequently, the as-grown benzothiazolium crystals exhibit excellent characteristics for THz wave generation, particularly at near-infrared pump wavelengths around 1100 nm, which is very promising given the availability of femtosecond laser sources at this wavelength, where current conventional THz generators deliver relatively low optical-to-THz conversion efficiencies.

Full Color Tunable Aggregation-Induced Emission Luminogen for Bioimaging Based on an Indolizine Molecular Framework.

By taking advantage of a unique mechanism of aggregation-induced emission (AIE) phenomena, AIE luminogens (AIEgens) have been provided as a solution to overcome the limitations of conventional fluorophores bearing the feature of aggregation-caused quenching (ACQ) phenomena. Especially, AIEgens paved the way to develop fluorogenic probes ideal for fluorescent imaging in live cell conditions. Despite the high demand for discovery of new AIEgens, it is still challenging to find a versatile molecular platform to generate diverse AIEgens.

Asymmetric Synthesis of 1-Benzazepine Derivatives via Copper-Catalyzed Intramolecular Reductive Cyclization.

An asymmetric construction of enantioenriched 2,3-substituted-1-benzazepine derivatives containing a cyclic tertiary amine moiety was developed by copper-catalyzed reductive intramolecular cyclization of ()-dienyl arenes with a tethered ketimine. This protocol involves tandem chemo-, regio-, and enantioselective hydrocupration and asymmetric cyclization in the presence of a chiral bisphosphine-copper catalyst. Under mild conditions, a broad range of 1-benzazepine derivatives was obtained in good to high yields with high degrees of diastereoselectivity and enantioselectivity.

Emodin-nicotinamide (1:2) cocrystal identified by thermal screening to improve emodin solubility.

Emodin (EM), an anthraquinone obtained from natural products, is known for many pharmacological activities. However, further evaluation and interpretation of toxicity or pharmacological activity of emodin are limited due to its poor aqueous solubility. We aimed to identify an emodin cocrystal with improved pharmaceutical properties.

Homochiral Asymmetric-Shaped Electron-Transporting Materials for Efficient Non-Fullerene Perovskite Solar Cells.

A design strategy is proposed for electron-transporting materials (ETMs) with homochiral asymmetric-shaped groups for highly efficient non-fullerene perovskite solar cells (PSCs). The electron transporting N,N'-bis[(R)-1-phenylethyl]naphthalene-1,4,5,8-tetracarboxylic diimide (NDI-PhE) consists of two asymmetric-shaped chiral (R)-1-phenylethyl (PhE) groups that act as solubilizing groups by reducing molecular symmetry and increasing the free volume. NDI-PhE exhibits excellent film-forming ability with high solubility in various organic solvents [about two times higher solubility than the widely used fullerene-based phenyl-C -butyric acid methyl ester (PCBM) in o-dichlorobenzene].

High-Performance Visible-Blind UV Phototransistors Based on n-Type Naphthalene Diimide Nanomaterials.

This study investigates the performance of single-crystalline nanomaterials of wide-band gap naphthalene diimide (NDI) derivatives with methylene-bridged aromatic side chains. Such materials are found to be easily used as high-performance, visible-blind near-UV light detectors. NDI single-crystalline nanoribbons are assembled using a simple solution-based process (without solvent-inclusion problems), which is then applied to organic phototransistors (OPTs).

Molecular Viscosity Sensors with Two Rotators for Optimizing the Fluorescence Intensity-Contrast Trade-Off.

A series of fluorescent molecular rotors obtained by introducing two rotational groups ("rotators"), which exhibit different rotational and electron-donating abilities, are discussed. Whereas the control molecular rotor, PH, includes a single rotator (the widely used phenyl group), the PO molecular rotors consist of two rotators (a phenyl group and an alkoxy group), which exhibit simultaneous strongly electron-donating and easy rotational abilities. Compared with the control rotor PH, PO molecular rotors exhibited one order of magnitude higher quantum yield (fluorescence intensity) and simultaneously exhibited significantly higher fluorescence contrast.

Crystal Structure Analysis of the First Discovered Stability-Enhanced Solid State of Tenofovir Disoproxil Free Base Using Single Crystal X-ray Diffraction.

Tenofovir disoproxil (TD), an anti-virus drug, is currently marketed under its most stable form, Form-I of Tenofovir disoproxil fumarate (TDF). However, studies regarding the properties of TD free base crystal as a promising drug as well as its crystal structure have not yet been reported. This assumption was made because TD free base is not directly produced in a solid form during the manufacturing process.

Benzothiazolium Single Crystals: A New Class of Nonlinear Optical Crystals with Efficient THz Wave Generation.

Highly efficient nonlinear optical organic crystals are very attractive for various photonic applications including terahertz (THz) wave generation. Up to now, only two classes of ionic crystals based on either pyridinium or quinolinium with extremely large macroscopic optical nonlinearity have been developed. This study reports on a new class of organic nonlinear optical crystals introducing electron-accepting benzothiazolium, which exhibit higher electron-withdrawing strength than pyridinium and quinolinium in benchmark crystals.

Crystal structure of the mixed-metal thio-phosphate Nb1.18V0.82PS10.

The mixed-metal thio-phosphate, Nb1.18V0.82PS10 (niobium vanadium phospho-rus deca-sulfide), has been prepared though solid state reactions using an alkali-metal halide flux.

The mixed-metal tris-(di-sulfide) thio-phosphate, KNb1.77Ta0.23PS10.

The title compound catena-poly[potassium [tri-μ-disulfido-μ-tetra-thiophos-pha-to-di[niobate(IV)/tantalate(IV)(0.885/0.115)]]], has been obtained through the reaction of the elements with KCl.

High-power broadband organic THz generator.

The high-power broadband terahertz (THz) generator is an essential tool for a wide range of THz applications. Here, we present a novel highly efficient electro-optic quinolinium single crystal for THz wave generation. For obtaining intense and broadband THz waves by optical-to-THz frequency conversion, a quinolinium crystal was developed to fulfill all the requirements, which are in general extremely difficult to maintain simultaneously in a single medium, such as a large macroscopic electro-optic response and excellent crystal characteristics including a large crystal size with desired facets, good environmental stability, high optical quality, wide transparency range, and controllable crystal thickness.

The monoclinic form of trilithium dichromium(III) tris-(orthophosphate).

The monoclinic form of trilithium dichromium(III) tris-(ortho-phosphate), Li3Cr2(PO4)3, was prepared by the reactive halide flux method. The structure of the title compound is composed of a three-dimensional anionic framework with composition ∞ (3)[Cr2(PO4)3](3-) and Li(+) ions situated in the empty channels. The rigid framework built up from CrO6 octa-hedra and PO4 tetra-hedra is the same as that found in other monoclinic Li3 M 2(PO4)3 (M = Fe, Sc, V) phases.

Reinvestigation of trilithium divanadium(III) tris-(orthophosphate), Li(3)V(2)(PO(4))(3), based on single-crystal X-ray data.

The structure of Li(3)V(2)(PO(4))(3) has been reinvestigated from single-crystal X-ray data. Although the results of the previous studies (all based on powder diffraction data) are comparable with our redetermination, all atoms were refined with anisotropic displacement parameters in the current study, and the resulting bond lengths are more accurate than those determined from powder diffraction data. The title compound adopts the Li(3)Fe(2)(PO(4))(3) structure type.

TiGeS(3).

The new ternary titanium(II) thio-germanate(IV), TiGeS(3), was synthesized using the reactive halide flux method. The title compound shows features of a ribbon-type structure formed from double chains composed of edge-sharing octa-hedral TiS(6) and pyramidal GeS(3) units, with all atoms in the asymmmetric unit positioned on mirror planes. While the TiS(6) octa-hedron is regular, the coordination around the Ge atom is rather irregular, which can be described as [3 + 3].

Ti insertion in the MTe(5) (M = Zr, Hf) structure type: Hf(0.78)Ti(0.22)Te(5).

The group 5 mixed-metal telluride, Hf(0.78)Ti(0.22)Te(5) (hafnium titanium penta-telluride), is isostructural with the binary phases HfTe(5) and ZrTe(5) and forms a layered structure extending parallel to (010).

N-heterocyclic carbene catalyzed domino cyclization of propargylic alcohols and benzoyl isocyanates.

N-Hetereocyclic carbenes (NHCs) were found to be efficient catalysts for the cyclization of propargylic alcohols and isocyanates. Domino cyclization reactions were carried out using isopropyl-substituted imidazolium salt as a precatalyst, and a wide range of substituted oxazolidinones were obtained in high yields.

The mixed-valent titanium phosphate, Li(2)Ti(2)(PO(4))(3), dilithium dititanium(III/IV) tris-(orthophosphate).

The mixed-valent titanium phosphate, Li(2)Ti(2)(PO(4))(3), has been prepared by the reactive halide flux method. The title compound is isostructural with Li(2)TiM(PO(4))(3) (M = Fe, Cr) and Li(2)FeZr(PO(4))(3) and has the same (3) (∞)[Ti(2)(PO(4))(3)](2-) framework as the previously reported Li(3-) (x)M(2)(PO(4))(3) phases. The framework is built up from corner-sharing TiO(6) octa-hedra and PO(4) tetra-hedra, one of which has 2 symmetry.

Reinvestigation of the low-temperature form of Ag(2)Se (naumannite) based on single-crystal data.

The crystal structure of the low-temperature form of synthetic naumannite [disilver(I) selenide], Ag(2)Se, has been reinvestigated based on single-crystal data. In comparison with previous powder diffraction studies, anisotropic displacement parameters are additionally reported. The structure is composed of Se layers and two crystallographically independent Ag atoms.

A new mixed group 5 metal selenide, Nb(1.41)V(0.59)Se(9).

The new mixed-metallic phase, niobium vanadium nona-selenide, (Nb(2-x)V(x))Se(9) (0.18≤ x ≤ 0.59) is isostructural with monoclinic V(2)Se(9).

KNb(1.75)V(0.25)PS(10).

The title compound, potassium diniobium vanadium phospho-rus deca-sulfide, KNb(1.75)V(0.25)PS(10), was obtained by reaction of the elements with a eutectic mixture of KCl/LiCl.

Preparation of half-metallocenes of thiophene-fused and tetrahydroquinoline-linked cyclopentadienyl ligands for ethylene/α-olefin copolymerization.

Directed ortho-lithiation of the lithium carbamates generated from tetrahydroquinoline or tetrahydroquinaldine enables one-step preparation of thiophene-fused and tetrahydroquinoline-linked cyclopentadienes [2-R(1)-3-R(2)-4,5-dimethyl-6-(2-R(3)-2,3,4,5-tetrahydroquinolin-8-yl)-4H-cyclopenta[b]thiophene (R(1), R(2), R(3) = H or methyl)], from which titanium(iv) and zirconium(iv) complexes are prepared. The molecular structures of Me(2)Ti-complexes (12, R(1) = R(2) = Me, R(3) = H; 14, R(1) = R(2) = R(3) = Me) and Cl(2)Zr-complex (17, R(1) = R(2) = Me, R(3) = H) are determined by X-ray crystallography. The Me(2)Ti-complexes, 14 and 15 (R(1) = R(3) = Me, R(2) = H) show excellent activities (62 and 54 × 10(6) g/molTi·h) in ethylene/1-octene copolymerization, even when activated with small amount of MAO (Al/Ti = 1000).