Copolymers Containing 1-Methyl-2-phenyl-imidazole Moieties as Permanent Dipole Generating Units: Synthesis, Spectroscopic, Electrochemical, and Photovoltaic Properties.

New donor-acceptor conjugated alternating or random copolymers containing 1-methyl-2-phenylbenzimidazole and benzothiadiazole (), diketopyrrolopyrrole (), or both acceptors () are reported. The specific feature of these copolymers is the presence of a permanent dipole-bearing moiety (1-methyl-2-phenyl imidazole (MPI)) fused with the 1,4-phenylene ring of the polymer main chain. For comparative reasons, polymers of the same main chain but deprived of the MPI group were prepared, namely, with diketopyrrolopyrrole and with both acceptors.

From Red to Green Luminescence via Surface Functionalization. Effect of 2-(5-Mercaptothien-2-yl)-8-(thien-2-yl)-5-hexylthieno[3,4-]pyrrole-4,6-dione Ligands on the Photoluminescence of Alloyed Ag-In-Zn-S Nanocrystals.

A semiconducting molecule containing a thiol anchor group, namely 2-(5-mercaptothien-2-yl)-8-(thien-2-yl)-5-hexylthieno[3,4-]pyrrole-4,6-dione (abbreviated as D-A-D-SH), was designed, synthesized, and used as a ligand in nonstoichiometric quaternary nanocrystals of composition AgInZnS(S) to give an inorganic/organic hybrid. Detailed NMR studies indicate that D-A-D-SH ligands are present in two coordination spheres in the organic part of the hybrid: (i) inner in which the ligand molecules form direct bonds with the nanocrystal surface and (ii) outer in which the ligand molecules do not form direct bonds with the inorganic core. Exchange of the initial ligands (stearic acid and 1-aminooctadecane) for D-A-D-SH induces a distinct change of the photoluminescence.

2-Iodomalondialdehyde is an abundant component of soluble organic iodine in atmospheric wet precipitation.

Iodine plays an important role in the environment and life. In the atmosphere, iodine is present in the form of inorganic and organic compounds. In this study, we have analyzed atmospheric wet precipitation using ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS) for the presence of organoiodine compounds and found that the main organoiodine compound in atmospheric waters is 2-iodomalondialdehyde.

Direct Reductive Cyclocondensation of the Nitro Group with the Amido Group: Key Role of the Iminophosphorane Intermediate in the Synthesis of 1,4-Dibenzodiazepine Derivatives.

A class of dialkylamino-substituted dibenzodiazepines and their hetero analogues was synthesized by the intramolecular aza-Wittig condensation of the amido group with iminophosphoranes. The one-pot, two-step procedure includes reductive synthesis of the intermediate iminophosphoranes from the corresponding nitroamides and tributylphosphine.

Highly Luminescent Ag-In-Zn-S Quaternary Nanocrystals: Growth Mechanism and Surface Chemistry Elucidation.

The presented research is focused on the synthesis of alloyed Ag-In-Zn-S colloidal nanocrystals from a mixture of simple metal precursors such as AgNO, InCl, zinc stearate combined with 1-dodecanethiol (DDT), 1-octadecene (ODE), and sulfur dissolved in oleylamine (OLA). In particular, the focus is on the effect of the solvent (ODE vs 1,2-dichlorobenzene (DCB)) and the type of sulfur precursor (S/OLA vs S/ n-octylamine (OCA)) on the metal precursors reactivates and on the chemical composition, crystal structure, and luminescent properties of the resulting nanocrystals. The replacement of ODE by DCB as a solvent lowers the reactivity of metal precursors and results in a 3-fold decrease of the photoluminescence quantum yields (Q.

Oxygenation of RZn(N,O)-type complexes as an efficient route to zinc alkoxides not accessible via the classical alcoholysis path.

The controlled oxygenation of alkylzinc complexes supported by a 2-ester substituted pyrrolate ligand (L) leads to zinc alkoxides with an uncommon structural motif in the solid state: a trimer [(L)Zn(μ-OBu)] with the central [Zn(μ-OR)] ring and a tetramer [(L)Zn(μ-OEt)] with a heterocubane-type structure. Strikingly, these seemingly simple zinc alkoxides are not accessible via the classical alcoholysis route.

Transition-metal-free synthesis of 3-(1-pyrrolidinyl)quinolines and 3-(1-pyrrolidinyl)quinoline 1-oxides via a one-pot reaction of 3-(1-pyrrolidinyl)crotonates with nitrobenzenes.

A carbanion of tert-butyl 3-(1-pyrrolidinyl)crotonate adds to nitrobenzenes to form σ-adducts, which in the presence of pivaloyl chloride and triethylamine are converted into 3-(1-pyrrolidinyl)quinolines or 3-(1-pyrrolidinyl)quinoline 1-oxides depending on the nitrobenzene structure. This is the first methodology in which a quinoline ring is constructed from a substrate bearing a pyrrolidinyl ring. Starting from optically pure enamines, the method allows synthesis of the corresponding chiral products without racemisation.

Photoactive Langmuir-Blodgett, Freely Suspended and Free Standing Films of Carboxylate Ligand-Coated ZnO Nanocrystals.

A new possibility for the formation of macroscopic and photoactive structures from zinc oxide nanocrystals is described. Photoactive freely suspended and free-standing films of macroscopic area (up to few square millimeters) and submicrometer thickness (up to several hundreds of nanometers) composed of carboxylate ligand-coated zinc oxide nanocrystallites (RCO2-ZnO NCs) of diameter less than 5 nm are prepared according to a modified Langmuir-Schaefer method. First, the suspension of RCO2-ZnO NCs is applied onto the air/water interface.

'Clickable' ZnO nanocrystals: the superiority of a novel organometallic approach over the inorganic sol-gel procedure.

We demonstrate for the first time a highly efficient Cu(i)-catalyzed alkyne-azide cycloaddition reaction on the surface of ZnO nanocrystals with retention of their photoluminescence properties. Our comparative studies highlight the superiority of a novel self-supporting organometallic method for the preparation of brightly luminescent and well-passivated ZnO nanocrystals over the traditional sol-gel procedure.

Structural diversity of alkylzinc complexes with pyrrole-based N,O-ligands: from molecular complexes to coordination polymers.

The equimolar reaction of R2Zn (where R = Et or (t)Bu) with pyrrole-based N,O-proligands afforded a series of alkylzinc compounds with a variety of intriguing structures including a hexanuclear macrocyclic complex and 1D coordination polymers with versatile intramolecular or intermolecular bonding modes.

Cyclic π-electron delocalization in non-planar linear acenes.

Based on the experimental data of newly determined structures of per-substituted naphthalenes by halogen atoms (F, Cl and Br) and perchloroanthracene, as well as on the molecular modeling we have shown that deviation from planarity leads to relatively small changes in the cyclic π-electron delocalization of acenes. Per-substituted naphthalenes are twisted, whereas perchloroanthracene adopts a boat conformation in the solid state. For the most distorted case - perbromonaphthalene twisted by 34.

Towards Organized Hybrid Nanomaterials at the Air/Water Interface Based on Liquid-Crystal/ZnO Nanocrystals.

The ability to self-assemble nanosized ligand-stabilized metal oxide or semiconductor materials offers an intriguing route to engineer nanomaterials with new tailored properties from the disparate components. We describe a novel one-pot two-step organometallic approach to prepare ZnO nanocrystals (NCs) coated with deprotonated 4-(dodecyloxy)benzoic acid (i.e.

General synthesis of 2,1-benzisoxazoles (anthranils) from nitroarenes and benzylic C-H acids in aprotic media promoted by combination of strong bases and silylating agents.

Carbanions of phenylacetonitriles, benzyl sulfones, and dialkyl benzylphosphonates add nitroarenes at the ortho-position to the nitro group to form [Formula: see text]-adducts that, upon treatment with trialkylchlorosilane and additional base (t-BuOK or DBU), transform into 3-aryl-2,1-benzisoxazoles in moderate-to-good yields.

Efficient synthesis of manganese(II) carboxylates: from a trinuclear cluster [Mn3(PhCO2)6(THF)4] to a unique [Mn(PhCO2)2]n chiral 3D network.

An efficient synthetic procedure for obtaining manganese carboxylates including a trinuclear cluster [Mn3(PhCO2)6(THF)4]2 and a unique [Mn(PhCO2)2]n chiral 3D network is reported. The procedure involves a simple redox process, in which acidic protons are reduced to gaseous hydrogen by oxidizing metallic manganese under solvothermal conditions.

Simple synthesis of pyrrolo[3,2-e]indole-1-carbonitriles.

Alkylation of 5-nitroindol-4-ylacetonitriles with ethyl chloroacetate, α-halomethyl ketones, and chloroacetonitrile followed by a treatment of the products with chlorotrimethylsilane in the presence of DBU gives 1-cyanopyrrolo[3,2-e]indoles substituted in position 2 with electron-withdrawing groups.

Synthesis of pyrrolo[3,2-]phenazines from 5-nitroindoles and anilines.

Abstract: Anilines react with 5-nitroindoles in the presence of -BuOK in ,-dimethylformamide (DMF) to form 5-nitroso-4-arylaminoindoles that in turn when treated with ,-bis(trimethylsilyl)acetamide cyclize to pyrrolo[3,2-]phenazines. In an alternative approach pyrrolo[3,2-]phenazines are formed from aminoindoles and nitroarenes.

Excited state intramolecular proton transfer in electron-rich and electron-poor derivatives of 10-hydroxybenzo[h]quinoline.

Eight previously inaccessible derivatives of 10-hydroxybenzo[h]quinoline were prepared via a straightforward strategy comprising formation of the benzo[h]quinoline skeleton followed by C-H acetoxylation at position 10. The occurrence of excited state intramolecular proton transfer (ESIPT) was detected in all cases since emission was observed only from the excited keto-tautomer. Studies on derivatives bearing both electron-donating and electron-withdrawing groups adjacent to the pyridine ring allowed us to identify some design patterns giving rise to NIR emission and large Stokes shifts.

Oxozinc carboxylates: a predesigned platform for modelling prototypical Zn-MOFs' reactivity toward water and donor solvents.

Two unique adducts of an oxozinc carboxylate cluster with H(2)O and THF were isolated and structurally characterized, [Zn(4)(μ(4)-O)(O(2)CR)(6)(H(2)O)(THF)]·2(THF) and [Zn(4)(μ(4)-O)(O(2)CR')(6)(THF)(3)] (where R = benzoate and R' = 9-antracenecarboxylate anion). The study shows that the zinc centers of the Zn(4)O core can easily form unique coordination environments without breaking of the Zn-O(carboxylate) bonds.