A copper complex of an unusual hydroxy–carboxylate ligand: [Cu(bpy)(C4H4O6)]

A copper(II) complex, (2,2′-bipyridine-κ2 N,N′)[2-hydroxy-2-(hydroxymethyl-κO)propanedioato-κ2 O 1,O 3]copper(II), [Cu(C4H4O6)(C10H8N2)], containing the unusual anionic chelating ligand 2-(hydroxymethyl)tartronate, has been synthesized. [Cu(bpy)2(NO3)](NO3) was mixed with ascorbic acid and Dabco (1,4-diazabicyclo[2.2.2]octane) in DMF (dimethylformamide) solution in the presence of air to produce the title compound. The structure consists of square-pyramidal complexes that are joined by Cu...O contacts [2.703 (2) Å] into centrosymmetric dimers. The C4H4O6 2− ligand, which occupies three coordination sites at Cu, has previously been identified as an oxidation product of ascorbate ion.

Crystal structure of zwitterionic 3,3′-[1,1′-(butane-1,4-diyl)bis(1H-imidazol-3-ium-3,1-diyl)]bis(propane-1-sulfonate) dihydrate

The crystal structure of the title compound, C16H26N4O6S2·2H2O, a water-soluble di-N-heterocyclic carbene ligand precursor was determined using a single crystal grown by the slow cooling of a hot N,N-dimethylformamide solution of the compound. The dihydrate crystallizes in the monoclinic space group P21/c, with half of the zwitterionic molecule and one water molecule of crystallization in the asymmetric unit. The remaining part of the molecule is completed by inversion symmetry. In the molecule, the imidazole ring planes are parallel with a plane-to-plane distance of 2.741 (2) Å. The supramolecular network is consolidated by hydrogen bonds of medium strength between the zwitterionic molecules and the water molecules of crystallization, as well as by π–π stacking interactions between the imidazole rings of neighbouring molecules and C—H...O hydrogen-bonding interactions.

Direct reversible decarboxylation from stable organic acids in dimethylformamide solution

Many classical and emerging methodologies in organic chemistry rely on carbon dioxide (CO2) extrusion to generate reactive intermediates for bond-forming events. Synthetic reactions that involve the microscopic reverse—the carboxylation of reactive intermediates—have conventionally been undertaken using very different conditions. We report that chemically stable C(sp3) carboxylates, such as arylacetic acids and malonate half-esters, undergo uncatalyzed reversible decarboxylation in dimethylformamide solution. Decarboxylation-carboxylation occurs with substrates resistant to protodecarboxylation by Brønsted acids under otherwise identical conditions. Isotopically labeled carboxylic acids can be prepared in high chemical and isotopic yield by simply supplying an atmosphere of 13CO2 to carboxylate salts in polar aprotic solvents. An understanding of carboxylate reactivity in solution enables conditions for the trapping of aldehydes, ketones, and α,β-unsaturated esters.

A Convenient, Scalable Process for the Preparation and Purification of Calcium Acamprosate

Calcium acamprosate (Campral, N-acetylhomotaurine calcium salt) is a well-established drug for the treatment of alcohol dependence. Its preparation is generally based on a three-step process with some remarkable drawbacks. To avoid these flaws, we have developed a direct, scalable, one-pot procedure for the preparation of calcium acamprosate entailing the nucleophilic opening of readily available 1,3-propanesultone with potassium acetamide (from acetamide and potassium tert-butoxide) in N,N-dimethylformamide solution, followed by in situ cation exchange by addition of calcium chloride at controlled pH, addition of 2-propanol (IPA) as a cosolvent, and removal of potassium chloride by selective precipitation. Calcium acamprosate (purity higher than 95%) is thus obtained in the commercial crystalline form in 74–77% yield.

Crystal structure and Hirshfeld surface analysis of 4-{[(anthracen-9-yl)methyl]amino}benzoic acid dimethylformamide monosolvate

The title compound, C22H17NO2·C3H7NO, was synthesized by condensation of an aromatic aldehyde with a secondary amine and subsequent reduction. It was crystallized from a dimethylformamide solution as a monosolvate, C22H17NO2·C3H7NO. The aromatic molecule is non-planar with a dihedral angle between the mean planes of the aniline moiety and the methyl anthracene moiety of 81.36 (8)°. The torsion angle of the Caryl—CH2—NH—Caryl backbone is 175.9 (2)°. The crystal structure exhibits a three-dimensional supramolecular network, resulting from hydrogen-bonding interactions between the carboxylic OH group and the solvent O atom as well as between the amine functionality and the O atom of the carboxylic group and additional C—H...π interactions. Hirshfeld surface analysis was performed to quantify the intermolecular interactions.

An Amine/Azine Functionalized MOF as a New Fluorescent Probe for Selective Sensing of Metal Ions

Metal-organic frameworks are a class of attractive materials for fluorescent sensing. Here, we report the exploration of fluorescent Zn-based amine/azine-functionalized MOF, TMU-17-NH2, ([Zn(NH2-BDC)(4-bpdb)].2DMF; NH2-BDC = amino-1,4-benzenedicarboxylic acid, 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-2,3-butadiene) for highly selective and sensitive detection of Fe3+ in DMF (N,N-dimethylformamide) solution. TMU-17-NH2 shows fast recognition of Fe3+ ions with a response time of <1 min and detection limit of 0.7 µM (40 ppb), and the luminescence is completely quenched in 10−3 M DMF solution of Fe3+. Furthermore, no interferences from 250 μM As3+, Cd2+, Zn2+, Co3+, Ni2+, Cu2+, Pb2+, Mn2+ and Al3+ were found for the detection of Fe3+, which suggests that functionalized TMU-17-NH2 is a promising luminescent probe for selectively sensing iron ions.

Aerosol-Assisted Chemical Deposition of Nanocomposite Material in the "Iron-Carbon-Oxygen" System

Based on aerosol chemical deposition, a method was developed and the process of simultaneous formation of a composite with a carbon matrix and iron oxide nanoparticles incorporated therein was developed. As the source of carbon, o-xylene is proposed, source of nanoscale iron oxide - stabilized and unstabilized magnetic fluid based on benzoic acid in dimethylformamide solution, where benzoic acid is addition source of carbon. The proposed method makes it possible to obtain composite materials of various types with several directions of growth.