Structural Features of Eu and Tb-Bipyridinedicarboxamide Complexes.

Photoluminescent lanthanide complexes of Eu and Tb as central atoms and ,-diisopropyl-[2,2'-bipyridine]-6,6'-dicarboxamide as ligand were synthesized. The structure of these complexes was established by single-crystal X-ray diffraction, mass spectrometry, H and C nuclear magnetic resonance, ultraviolet-visible, infrared spectroscopy, and thermogravimetry. Bipyridinic ligands provide formation of coordinatively saturated complexes of lanthanide ions and strong photoluminescence (PL).

Copper(II)-Mediated Iodination of 1-Nitroso-2-naphthol.

The 3-Iodo-1-nitrosonaphthalene-2-ol (I-NON) was obtained by the copper(II)-mediated iodination of 1-nitroso-2-naphthol (NON). The suitable reactants and optimized reaction conditions, providing 94% NMR yield of I-NON, included the usage of Cu(OAc)·HO and 1:2:8 Cu/NON/I molar ratio between the reactants. The obtained I-NON was characterized by elemental analyses (C, H, N), high-resolution ESI-MS, H and C{H} NMR, FTIR, UV-vis spectroscopy, TGA, and X-ray crystallography (XRD).

Predicting the catalytic activity of azolium-based halogen bond donors: an experimentally-verified theoretical study.

This report demonstrates the successful application of electrostatic surface potential distribution analysis for evaluating the relative catalytic activity of a series of azolium-based halogen bond donors. A strong correlation ( > 0.97) was observed between the positive electrostatic potential of the σ-hole on the halogen atom and the Gibbs free energy of activation of the model reactions (, halogen abstraction and carbonyl activation).

Phosphorescent Iridium(III) Complexes with Acyclic Diaminocarbene Ligands as Chemosensors for Mercury.

A new application for bis(cyclometalated) iridium(III) species containing ancillary acyclic diaminocarbene ligands, viz. for sensing of mercury(II) ions, is disclosed. A family of bis(cyclometalated) iridium(III) species supported by both parent isocyanide and acyclic diaminocarbene ligands was prepared, and their electrochemical and photophysical properties were evaluated, revealing efficient blue-green phosphorescence in solution with quantum yields of up to 55%.

3-Dialkylamino-1,2,4-triazoles via Zn-Catalyzed Acyl Hydrazide-Dialkylcyanamide Coupling.

Zinc(II)-catalyzed (10 mol % ZnCl) coupling of acyl hydrazides and dialkylcyanamides in ethanol leads to 3-dialkylamino-1,2,4-triazoles (76-99%; 17 examples). This reaction represents a novel, straightforward, and high-yielding approach to practically important 3-NR-1,2,4-triazoles, which utilizes commercially available and/or easily generated substrates. Seventeen new 3-NR-1,2,4-triazoles were characterized by HRESI-MS and IR, H, and C{H} NMR spectroscopies and five species additionally by single-crystal X-ray diffraction (XRD).

Cleavage of acyclic diaminocarbene ligands at an iridium(iii) center. Recognition of a new reactivity mode for carbene ligands.

Reaction of [Ir(μ-Cl)(ppy)] (1) with 4 equivs of CNCHX (X = F 2a, Cl 2b, Br 2c, I 2d) in the presence of 2 equivs of AgOTf in dichloromethane at 20-25 °C furnished the bisisocyanide complexes [Ir(ppy)(CNCHX)](OTf) ([3a-d](OTf); 72-87%). Reaction of [3a-d](OTf) with an excess of gaseous ammonia at room temperature gave the bisdiaminocarbene species [Ir(ppy){C(NH)NHCHX}](OTf) [5a-d](OTf) (73-83%); the two-step addition proceeds through an intermediate formation of appropriate monocarbene complexes [4a-d](OTf). Further reaction of [5a-d](OTf) with an excess of gaseous ammonia at 50 °C led to the cleavage of one diaminocarbene ligand to the cyanide ligand in [Ir(ppy)(CN){C(NH)NHCHX}] (6a-d) and this transformation is accompanied with the elimination of a substituted aniline.

TfOH-Promoted Reaction of 2,4-Diaryl-1,1,1-Trifluorobut-3-yn-2-oles with Arenes: Synthesis of 1,3-Diaryl-1-CF₃-Indenes and Versatility of the Reaction Mechanisms.

The TfOH-mediated reactions of 2,4-diaryl-1,1,1-trifluorobut-3-yn-2-oles (CF₃-substituted diaryl propargyl alcohols) with arenes in CH₂Cl₂ afford 1,3-diaryl-1-CF₃-indenes in yields up to 84%. This new process for synthesis of such CF₃-indenes is complete at room temperature within one hour. The synthetic potential, scope, and limitations of this reaction were illustrated by more than 70 examples.

Reactions of 1,5-Diaryl-3-(trifluoromethyl)pent-1-en-4-yn-3-yl Cations with Benzene in TfOH. Synthesis of CF-"Helicopter"-Like Molecules.

Trimethylsilyl ethers of 1,5-diaryl-3-(trifluoromethyl)pent-1-en-4-yn-3-oles in superacid CFSOH (TfOH) give rise to the corresponding intermediate CF-pentenynyl cations. These species react with benzene to afford conjugated CF-pentenynes, which undergo subsequent cyclization, first, into CF-cycloheptadienes and, finally, into unusual CF-"helicopter"-like bicyclic structures.

Metal-mediated reactions between dialkylcyanamides and acetamidoxime generate unusual (nitrosoguanidinate)nickel(ii) complexes.

The nitrosoguanidinate complexes [Ni{NH[double bond, length as m-dash]C(NR)NN(O)}] (R = Me1, (CH)O 2, (CH)3, (CH)4, (Me)Ph 5, Ph6, (p-MeCH)7) were obtained in low-to-moderate (12-26%) yields but reproducible yields in an unexpected metal-mediated reaction in MeOH between the nickel salt NiCl·2HO, N,N-disubstituted cyanamides NCNR, and the amidoxime MeC([double bond, length as m-dash]NOH)NH. These complexes were formed along with a spectrum of cyanamide-oxime coupling products. The IR and X-ray data indicate the delocalization within the NNO and NCN systems of the nitrosoguanidinate ligand.