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Abstract: The reaction of LiArMe6 [ArMe6 C6H3-2,6(C6H2-2,4,6-Me3)2] with InCl, [In(InI4)], InCl in the presence of LiI, or ‘GaI’ in toluene solution resulted in the isolation of the 1,2-diaryl-1,2-dihalogen derivatives [{InCl(ArMe6)}2]2 (1), [{InI(ArMe6)}2]2 (2), [{In4Cl2I2(ArMe6)4}] (3), and [{GaI(ArMe6)}2] (4). The indium derivatives 1–3 were isolated as tetrametallic complexes formed via the almost symmetric bridging by four halides of two In–In bonded, ArMe6In–InArMe6 moieties. In 1, the In4Cl4 core features almost parallel In–In units, linked by four almost symmetrically bridging chlorides. This yields a structure formed from two folded In2Cl2 rings, and two six-membered In4Cl2 boat-shaped rings that have common In–Cl edges. The structures of 2 and 3 also feature two ArMe6InInArMe6 units bridged by four halides. However, there is a large torsion angle between the two In–In vectors, so that the In4I4 (2) and In4Cl2I2 (3) cores are formed from four five-membered In3I2 (2) or In3ClI (3) rings. Compound 4 has a simple Ga–Ga bonded dimeric structure, in which the gallium atoms are three coordinated, being bonded to each other as well as to an iodine and an ArMe6 ligand. All the compounds were characterized by 1H and 13C {1H} NMR spectroscopy, and by X-ray crystallography. The structural differences between the gallium and indium derivatives is probably a result of the larger size and greater Lewis acidity of the indium centers. [Copyright &y& Elsevier]

Abstract: The nickel (0) compound Ni(COD)(GaAr′)2 (Ar′ = C6H3–2,6-(C6H3-2,6-i-Pr2)2), 1, was synthesized by the reaction of Ni(COD)2 (COD = 1,5-cyclooctadiene) with (GaAr′)2. Compound 1 reacted with ethylene at 25 °C and at 1 atm pressure to give the bimetallic cluster [Ni2(GaAr′)2(η1:η1-μ2-C2H4)], 2, through the incorporation of one molecule of ethylene and displacement of COD. The structure of 2 featured an unusual Ni2Ga2C2 core bicyclic structure in which the C2H4 moiety bridges the Ga···Ga edge of a Ga2Ni2 tetrahedron. The galliums each carry an η1-bonded Ar′ substituent which complexes the nickel atom by an η6–π interaction with one of its flanking Ar’ rings. [Copyright &y& Elsevier]

The first goal of this work was to explore the feasibility of diaryl-mercury species as the synthetic precursors of triaryl-gallium species GaAr* 3 (where Ar*= pH, 4; Ar*= 3,5-difluorophenyl, 5; and Ar*= 3,5-trifluoromethylphenyl, 6). Expecting that 4–6 behave as Lewis acids of different strength, the second purpose was to use them for the synthesis of either rollover or classic cyclometallated Ga compounds. Three analogous diaryl-mercury HgAr* 2 species, 1–3, were successfully synthesized. The structures of compounds 2 and 3 were confirmed by gas chromatography - mass spectrometry experiments. Additionally, compound 3 was analyzed through X-ray diffraction; in the crystal structure obtained, π-stacking interactions were observed. The only Ga compound synthesized was GaPh 3 , 4, because the presence of fluorine-containing groups in meta-position caused sublimation of the respective mercury diaryl compounds, impeding their reaction with gallium. The attempts toward the synthesis of the rollover or classic cyclometallated compounds in the reaction of 4 with bipyridine-, pyrazole- or benzo-imidazole- type ligands have failed. On the other hand, under the experimental conditions applied, water traces favored formation of the solid aryl-Ga cluster containing twelve Ga atoms [Ga 12 ], whereas the above-mentioned ligands were quantitatively recovered in the solution. The identity of aryl-gallium cluster was confirmed by electrospray ionization - high resolution mass spectrometry. Although Ga cluster was not expected, it is considered an important finding of this work, owing to the variety of possible applications and still limited data available on the synthesis and structural characterization of such compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel amino-pyridyl-benzothiazole derivatives were implemented as Zn2+ sensors. • A gradient turn-on luminescence response was observed upon coordination with Zn2+. • Instantaneous and selective determination in the 4.7 to 80 μM range was verified at pH 7.0. • The sensor revealed intracellular Zn2+ levels of some cancer cell lines. • The real-time epifluorescence distribution profiles correlated with the concentration and location of the target within living cells. Novel amino-pyridyl-benzothiazole-derivatives (PBT) were synthesized through cycloaddition/nucleophilic aromatic substitution reactions for the development of a turn-on fluorescence chemosensor that accurately determines Zn2+ in polar media. The selectivity, water-solubility, and overall analytical response were systematically optimized through incorporation of different aliphatic amines as substituents: pyrrolidine (PBT-Pyn), ethylenediamine (PBT-Et) or 1,3-propylenediamine (PBT-Pr). Those ligands presented intense dual radiative emissions in the blue/green region upon activation with a 395 nm LED, which were attributed to the local excitation and internal energy transfer states. Although no variations were observed upon the interaction of Zn2+ with PBT-Pyn, both turn-off and turn-on responses were observed upon its interaction with PBT-Et. These responses depended on the ligand concentration and the associated inner filter effects. Thereby, PBT-Pr was selected for a deeper evaluation towards photoluminescence determination of Zn2+ due to its exclusive turn-on response and major sensibility obtained at pH 7.0, making it very convenient for analysis in physiological media. Under those conditions, the detection limits were 1.9 µM and 4.7 µM for measurements in aqueous or ethanolic solutions, respectively, with linear ranges up to 40 and 80 μM. The selectivity and good biocompatibility of the chemosensor were demonstrated through cell-viability assays with MCF-7, 3T3-L1 and HT-29 cell lines. The probe was then applied for the real-time epifluorescence imaging of Zn2+, observing emission intensities and distribution profiles that correlated with the concentration and location of the target within living cells. [ABSTRACT FROM AUTHOR]

A new small family of Ru, Rh, and Ir piano-stool complexes partially containing the bulky acac diMes , p -Cymene and Cp* ligands was synthetized and characterized. Their catalytic activity in transfer hydrogenation reaction was tested. The turn over frequency (TOF) values for aromatic- and alkyl-ketones giving the corresponding desired alcohols were increased in two orders of magnitude by using microwave heating compared with conventional thermal method. Ru, Rh and Ir β-Dimesitylaceonate piano stool complexes were used as catalytic precursors on the transfer hydrogenation reaction; the microwave irradiation heating raise the TOF values in two order of magnitude comparing with the thermal conditions. Image 1 [ABSTRACT FROM AUTHOR]

Graphical abstract Neutral and cationic nickel, palladium and platinum complexes containing a new N,N,S-tridentate ligand have been prepared and characterized. The structure of the ligand and eight complexes was determinate by X-ray crystallographic analysis. Ligand can be both mono- or di-deprotonated under mild reaction conditions. Studies in Heck reaction and antiproliferative activities are reported. Abstract Organometallic and coordination nickel, palladium and platinum complexes, neutral and cationic, with general formula [M(κ3-SacNac)X] and [M(κ3-SacNac)L′][BPh 4 ] (where M = Ni, Pd and Pt, X = Me, Cl, 1 – 6 ; M = Ni, X = N 3 , SMe, 7 – 8 ; M = Pd, X = I, 13 ; M = Ni and Pd, L′ = PPh 3 , 9 – 10 ; M = Ni and Pt, X = PMe 3 , dmso, 11 – 12) containing a new SacNac N,N,S-tridentate ligand [C 6 H 5 (S)CCH 2 C(N-CH 2 CH 2 NHC 6 H 5)CH 3 ] were synthetized and obtained as microcrystalline solids. Compounds 2 – 13 were fully characterized by elemental analysis, IR, 1D and 2D NMR spectroscopy. The structure of the ligand and eight complexes was determined by X-ray crystallographic analysis. The ligand can be both mono- or bi-deprotonated under mild reaction conditions. Results in Heck reaction and antiproliferative activities are reported. [ABSTRACT FROM AUTHOR]

Abstract: Nickel and palladium organometallic [M(R)(NNO)] (R=CH2CMe2C6H5; M=Pd, 1 , Ni, 2 ; R=Me, M=Pd, 3 , Ni, 4 ; R=CH2SiMe3, M=Ni, 5 ) and coordination [MCl(NNO)] (M=Pd(II), 6, Ni(II), 7), [Ni(NNO)2], 8, complexes containing the potentially tridentate Schiff base NNO-donor ligand which is the condensation product of 2-hidroxynaphtaldehyde and N-benzylethylenediamine, were prepared and characterized by elemental analysis, IR and NMR spectroscopy. The crystal structure of 8 was determined by single X-ray diffraction measurements. Complexes 1–6 had a square planar structure with the ligand being tridentate through the NNO atoms. On the other hand compound 7 presented a conformational equilibrium in dissolution at room temperature and a rigid square-planar structure at 220K. The crystal structure of 8 indicated a monoclinic lattice, with a P2(1)/c space group, a =13.1799(8), b =14.5556(9), c =17.5018(11)Å, b =98.0420 (10)°, Z =4. The central Ni atom in 8 was in a N4O2 coordination sphere formed by two NNO Schiff base ligands. In this structure two of the Ni–N bonds trans to the oxygen atoms were significantly longer than the other two Ni–N bonds, 2.0175(17), 2.2761(17) versus 2.0070(17), 2.1794(14)Å. The two oxygen phenol atoms of the chelating ligands were cis and the distances of the Ni(II)–O(phenol) bond were 2.0410(14) and 2.0415(14)Å, respectively. [Copyright &y& Elsevier]