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The synthesis of the dialkyltin complex [SnMe2-(H2L)] of an octadentate Schiff-base pyrrol macrocycle is described in which the gross Pacman geometry enforces structural discrimination between the two methyl groups. The presence of the metal-free compertment engenders the formation of mixed-metal Sn-Fe and Sn-Zn complexes in which the macrocyclic cleft has distorted considerably upon the introduction of the transition metal cation.

The cuboctameric hydroxysilsesquioxane (c-C5H9)(7)Si8O12(OH) (2), obtained after hydrolysis of (c-C5H9)(7)Si8O12Cl (1), and triphenylsilanol have been applied as model supports for silica-grafted olefin polymerization catalysts. The ligands were introduced on group 4 metals by either chloride metathesis or protonolysis. Treatment of Cp"MCl3 (M = Ti, Zr; Cp" = 1,3-C5H3(SiMe3)(2)) with silsesquioxane and siloxylithium or -thallium salts, [(c-C5H9)(7)Si8O13]M' (M' = Tl (3), Li (4), Li.TMEDA (5)) or Ph3SiOTl gave either the dichloride complexes Cp"[(c-C5H9)(7)Si8O13]MCl2 (M = Ti (6a), Zr (7a)) and Cp"[Ph3SiO]TiCl2 (8a) or the monochloride species Cp"[(c-C5H9)(7)Si8O13](2)MCl (M - Ti (6b), Zr (7b)) and Cp"[Ph3SiO](2)MCl (M = Ti (8b), Zr (9)). Similarly, protonolysis of Cp"MR3 with the silanols 2 and Ph3SiOH yielded the corresponding silsesquioxane bis(alkyl) complexes Cp"[(c-C5H9)(7)Si8O13]TiR2 (R = CH2Ph (10a), Me (10b)) and triphenylsiloxy bis(alkyl) compounds Cp"[Ph3SiO]MR2 (M = Ti, R = CH2Ph (11a), Me (11b); M = Zr, R = CH2Ph (12a)) and the monobenzyl complex Cp"[Ph3SiO](2)ZrCH2Ph (12b). When activated with MAO, not only the dichloride complexes (6a, 7a, 8a) but also the monochlorides (6b, 7b, 8b, 9) yield active ethylene polymerization catalysts. The observation that even complexes containing a tridentate silsesquioxane ligand, [(c-C5H9)(7)Si8O12]-MCp" (M = Ti (13), Zr (14)), form active ethylene polymerization catalysts when activated with MAO indicates that silsesquioxane and siloxy ligands are easily substituted by MAO. The silsesquioxane and siloxy bis(alkyl) complexes (10, 11, 12a) form active olefin polymerization catalysts when activated with B(C6F5)(3), which leaves the M-O bond unaffected. Although the different cone angles of (c-C5H9)(7)Si8O13 (155 degrees) and Ph3SiO (132 degrees) suggest otherwise, the effective steric congestion around the metal center of (c-C5H9)(7)Si8O13- and Ph3SiO-stabilized complexes was found to be reasonably comparable. The electronic differences between (c-C5H9)(7)Si8O12(OH) (2) and Ph3SiOH are more pronounced, pK(a) measurements and DFT calculations indicate that 2 is notably more Bronsted acidic and electron withdrawing than Ph3SiOH.

A series of intramolecularly coordinated organochalcogen compounds incorporating the 8-(dimethylamino)-1-naphthyl and 2-[(dimethylamino)methyl]phenyl groups has been synthesized. All the compounds were synthesized using the ortholithiation methodology. Insertion of elemental selenium into the Li-C bond of RLi (6) (R = 8-(dimethylamino)-1-naphthyl) afforded the lithium areneselenolate RSeLi (7). Oxidative workup of 7 yielded the yellow diselenide 8 in good yield. Reaction of 8 with a stoichiometric amount of sulfuryl chloride gave the monochloro derivative (9). Controlled bromination of diselenide (8) with bromine in carbon tetrachloride gave the stable selenenyl bromide (10). Compound 8 underwent facile reaction with a stoichiometric amount of iodine to give the corresponding novel monoiodo compound (11) in which selenium is covalently bonded to iodine. Attempts to synthesize the chalcogenides, R2E, 12 (E = Se) and 13 (E = Te), by the reaction of 6 with Se(dtc)(2) and Te(dtc)(2) (dtc = diethyldithiacarbamate), respectively, were unsuccessful. The reaction of 6 with Te(dtc)(2) afforded the stable RTe(dtc) (14) instead of the expected telluride R2Te (13). In contrast, the reaction of R'Li (17) (R' = 2-[(dimethylamino)methyl)phenyl] with Se(dtc)(2) and Te(dtc)(2) afforded the expected selenide R'Se-2 (18) and telluride R'Te-2 (19), respectively, in moderate yields. The compounds were characterized by elemental analysis, NMR (H-1, C-13, Se-77, Te-125), and mass spectral techniques. The structures of the compounds 9, 11, 14, and 18 were determined by X-ray crystallography. Although N ... E (E = Se or Te) nonbonded interactions are present in the solid state in all the derivatives, in solution the pyramidal inversion at the nitrogen center is not blocked, and as a result, the NMe2 signals are observed as sharp signals in the H-1 NMR spectra.

The hydrogen bonding properties, the nature of the tautomeric structure and dimerization of N-(2-carboxyphenyl)salicylidenimine 1 has been studied. The crystal and molecular structure of 1 has been determined by single-crystal X-ray diffraction analysis. This compound forms a dimer in the solid state, which is held together by two strong intermolecular O–H · · · O bridges [O(1) · · · O(2a) = 2.455(1) Å]. This dimeric structure is further stabilized by two intramolecular N–H · · · O hydrogen bonds [N(1) · · · O(1) = 2.654(1) and N(1) · · · O(2) = 2.663(1) Å]. In this way, an eight-membered pseudocycle is created. However, in methanol or acetonitrile solution, no dimerization was observed according to 1H-NMR, IR and UV measurements. It was also found that this compound exists as an intermediate form between a phenol-imine and an o-quinoid structure. In addition, a derivative soluble in chloroform, 2-[2-hydroxy-5-(2-butyl)benzylideneamino]benzoic acid 3, was examined for comparison.

Treatment of the silanol (c-C5H9)(7)Si8O12(OH) with Cp " Ti(CH2Ph)(3) (Cp " = 1,3-C5H3(SiMe3)(2)) or TiCl4 selectively affords the mono(silsesquioxane) complexes Cp "[(c-C5H9)7Sis0l3ITi(CH2Ph)(2) (1) and [(c-C5H9)(7)Si8O13]TiCl3 (2), respectively, while with M(CH2Ph)(4) (M = Ti, Zr, Hf) mixtures of products were obtained. When the disilanol (c-C5H9)(7)Si7O9(OSiMe3)(OH)(2) is reacted with M(CH2Ph)(4) (M = Ti, Zr), the bis(silsesquioxane) complexes [(c-C5H9)(7)Si7O11(OSiMe3)](2)M (M = Ti (3), Zr (4), Zr . 2THF (5)) are formed exclusively. With (PhCH2)(2)ZrCl2. OEt2 as precursor, the mono(silsesquioxane) complex [(c-C5H9)(7)Si7O11(OSiMe3)]ZrCl2. 2THF (6) can be isolated. M(CH2Ph)(4) (M = Ti, Zr, Hf) reacts smoothly with the tris(silanol)(c-C5H9)(7)Si7O9(OH)3 (III), giving the metallasilsesquioxane benzyl species, {[(c-C5H9)(7)Si7O12]MCH2Ph}(n) (M = Ti, n = 1(7); M = Zr, n = 2 (8); M = Hf, n = 2 (9)). Compounds 5 and 8 have been characterized by X-ray analysis. Dimer 8 consists of a zwitterionic-like structure with two electronically different metal sites. M-C bond hydrogenolysis of 8 and 9 affords the corresponding hydrides, which are active alpha-olefin hydrogenation catalysts. Without cocatalyst, the neutral dimers 8 and 9 are poor, though active ethylene polymerization catalysts (activity: (5-10) x 10(3) g PE/mol.h)). Addition of B(C6F5)(3) affords the cationic, mono(benzyl) complexes {[(c-C5H9)(7)Si7O12](2)M-2(CH2Ph)}((+)) (M = Zr, Hf): single-site catalysts(activity: (2-8) x 10(6) g PE/(mol.h)) that are considerably more active than the neutral 8 and 9. Whereas titanasilsesquioxanes 3 and 7 do not react with THF, the corresponding zirconasilsesquioxanes 4 and g form bis(THF) adducts, [(c-C5H9)(7)Si7O11(OSiMe3)](2)Zr . 2THF (5) and [(c-C5H9)(7)Si7O12]ZrCH2Ph . 2THF (10), which suggests that the titanium complexes are less electrophilic than the zirconium ones. Accordingly, the titanium complex 7 does not react with dihydrogen and is inactive in ethylene polymerization.

The title compound, [Ni2Cl2(C9H10NO2)(2)]center dot CH3OH, is a dinuclear unit built up by two nickel(II) complexes, bridged by two Cl atoms. The coordination geometry around each Ni-II atom can be considered as distorted square-pyramidal, with the tridendate chelate Schiff base ligands coordinating in a trans conformation through their imine N atom and phenoxy and alkoxy O atoms.

International audience; It is shown that there is no deuterium-isotope incorporation in the vinylidene CHPh group of RuDX(CCHPh)((PBu2Me)-Bu-t)(2) (X = Cl, I) on the time scale of 24 h at 25 degrees C, which indicates that the (unobserved) isomeric alkylidyne species RuX(CCHDPh)((PBu2Me)-Bu-t)(2) is not readily accessible under these conditions. Ab initio (B3LYP) calculations on the model MHCl(CCH2)(PH3)(2) (M = OS, Ru) show the ethylidyne isomer MCl(CCH3)(PH3)(2) to be close in energy (2.5, -1.1 kcal mol(-1) for Os and Ru, respectively) and effectively inaccessible at 25 degrees C due to the high energy (54.2, 45.5 kcal mol(-1) for Os and Ru, respectively) of the transition state for such a 1,3-migration. In contrast, simple rotation of the CCH2 group of MHCl(CCH2)(PH3)(2) by 180 degrees around the C-C axis is calculated to have a low barrier (8.1, 4.3 kcal mol(-1) for Os and Ru, respectively), indicating this to be the mechanism for isomerization observed in OsHCl(CCHPh)((PPr3)-Pr-i)(2).

The MOLFDIR package of programs is used to perform fully relativistic all-electron Dirac-Fock and Dirac-Fock-Breit calculations for the the XeFn (n = 1, 2, 4, 6) molecules assuming experimental symmetries. The Xe-F bound length for XeF2, XeF4, and XeF6 is optimized and the total ground-state energies are reported. The variation of the relativistic energy and the Breit correction with the internuclear distance is plotted. The role of relativistic corrections in the proper prediction of the Xe-F distance and the dissociation energy of the molecule is discussed. The problem of the reduction of the number of scalar two-electron integrals is studied. Our results illustrate the possibilities, difficulties, and limitations of the finite basis Dirac-Fock calculations for polyatomic molecules of different symmetries. (C) 1997 by John Wiley & Sons, Inc.

Substitution of the chloride in Cp ∗ FvTiCl with MR (Fv  C 5 Me 4 CH 2 ; R  Me, CH 2 SiMe 3 , CH 2 CMe 3 , CH  CH 2 , M  Li; R  CH 2 Ph, M  K; R  C 3 H 5 , M  MgCl; R  Ph, M  Na · NaCl) gives Cp ∗ FvTiR. NMR spectroscopic evidence points towards a series of structurally related compounds with a bent-sandwich geometry. The substituent R is positioned in the wedge, midway below the exocyclic methylene group and a neighbouring methyl group of the fulvene. Thermolysis of Cp ∗ FvTiR gives, dependent on the substituent R, reduction to Cp ∗ FvTi (R  CH 2 Ph) or the double ring metallated Cp ∗ [C 5 Me 3 (CH 2 ) 2 ]Ti (R  CH 2 XMe 3 , X  C, Si) or Cp ∗ FvTiCH=CHMe (R = η 3 -C 3 H 5 ).

A range of novel chiral tellurium compounds having an azomethine functional group in the position ortho to tellurium has been synthesized by the reaction of the tellurium-containing aldehydes bis(o-formylphenyl) telluride (1) and o-(butyltelluro)benzaldehyde (4) with chiral amines (R)-(+)-(1-pheylethylamine) and (1R,2S)-(-)-norephedrine, respectively. The precursor aldehydes were prepared by using a reported procedure with slight but advantageous modifications. During the preparation of o-(butyltelluro)benzaldehyde, interesting side products, namely bis(o-formylphenyl) ditelluride ethylene acetal 5, bis(o-formylphenyl) tritelluride (6), and bis(o-formylphenyl) ditelluride (7) were isolated in moderate yields. The ditelluride 7 has been characterized by single-crystal X-ray diffraction studies. The liquid Schiff bases 10 and 11 were further characterized by derivatizing with liquid bromine. The title compound was obtained in excellent yield by reacting the Schiff base 11 with elemental bromine. Detailed NMR studies indicated the presence of a rigid environment for the hydroxyl group. Single-crystal X-ray determinations of the crystals obtained from the different batches indicated. the presence of the two pseudopolymorphic forms 13a and 13b, respectively. In the case of 13a there is one molecule of CH3CN as solvent of crystallization, whereas in 13b half a molecule of CH3CN per molecule of the title compound lies along the 2-fold axis. In 13a the hydroxyl hydrogen is hydrogen-bonded to the nitrogen of the solvent molecule, whereas in 13b it is hydrogen-bonded to the bromine of the neighboring molecule.

The successful synthesis of amylose brushes via enzymatic ‘‘grafting from’’ polymerization and the detailed characterization of all synthetic steps by X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry measurements are reported. Au and Si surfaces are amino-functionalized with self-assembled monolayers (SAMs) of cystamine and 3-aminopropyldimethyethoxysilane (APDMES), respectively. Maltoheptaose is covalently attached to the amino-functionalized Au and Si surfaces via reductive amination. Amylose brushes are grown from maltoheptaose modified Au and Si surfaces with enzymatic polymerization using potato phosphorylase and Rabbit Muscle phosphorylase, as evidenced by spectroscopic ellipsometry and XPS measurements.

The formation of amylose-polystyrene inclusion complexes via a novel two-step approach is described. In the first-step, styrene was inserted inside the amylose helical cavity, followed by free radical polymerization in the second step. The inclusion complexes were characterized by attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), ultraviolet spectroscopy (UV), X-ray diffraction (XRD), atomic force microscopy (AFM), and differential scanning calorimetry (DSC). The formation of polystyrene was confirmed by gel permeation chromatography (GPC). The molecular weight of polystyrene can be varied by using amylose bearing different molar masses. The approach described here is general and could be used to synthesize other host-polymer inclusion complexes for which long chains of polymeric guests are difficult to insert into the host cavity.

The ruthenium(II)–cymene complexes [Ru(η 6 -cymene)(bha)Cl] with substituted halogenobenzohydroxamato (bha) ligands (substituents = 4-F, 4-Cl, 4-Br, 2,4-F 2 , 3,4-F 2 , 2,5-F 2 , 2,6-F 2 ) have been synthesized and characterized by elemental analysis, IR, 1 H NMR, 13 C NMR, cyclic voltammetry and controlled-potential electrolysis, and density functional theory (DFT) studies. The compositions of their frontier molecular orbitals (MOs) were established by DFT calculations, and the oxidation and reduction potentials are shown to follow the orders of the estimated vertical ionization potential and electron affinity, respectively. The electrochemical E L Lever parameter is estimated for the first time for the various bha ligands, which can thus be ordered according to their electron-donor character. All complexes exhibit very strong protein tyrosine kinase (PTK) inhibitory activity, even much higher than that of genistein, the clinically used PTK inhibitory drug. The complex containing the 2,4-difluorobenzohydroxamato ligand is the most active one, and the dependences of the PTK activity of the complexes and of their redox potentials on the ring substituents are discussed.

International audience; This work aimed to characterize the molecular structure and functional properties of starches isolated from wild Dioscorea yams grown at the Amazons, using conventional and up-to-date methodologies. Among the high purity starches isolated (>= 99%), the chain lengths were similar, whereas variations in gelatinization profile were observed. Starches have shown varied-shaped granules with monomodal distribution, and B-type crystallinity. Variations in amylose contents found by three analyses were hypothesized being related to intermediate material. Linear chain lengths were similar, and their amylopectins showed a dense, spherical conformation and similar molecular characteristics. The average molar mass and the radius of gyration of the chromatograms of the yam amylopectin, (M) over bar (W) and (R) over bar (G) were ranging between 174 x 10(6) g mol(-1) and 237 x 10(6) g mol(-1), and 201 nm and 233 nm, respectively. The white yams starches were more sensible to enzymes than the other two. All starches have shown a wide range of functional and nutritional properties. (C) 2013 Elsevier Ltd. All rights reserved.

Two citric acid crosslinked gamma-cyclodextrin oligomers (p gamma-CyD) with a MW of 21-33 kDa and 10-15 gamma-CyD units per molecule were prepared by following green chemistry methods and were fully characterized. The non-covalent association of doxorubicin (DOX) with these macromolecules was investigated in neutral aqueous medium by means of circular dichroism (CD), UV-vis absorption and fluorescence. Global analysis of multiwavelength spectroscopic CD and fluorescence titration data, taking into account the DOX monomer-dimer equilibrium, evidenced the formation of 1 : 1 and 1 : 2 p gamma-CyD unit-DOX complexes. The binding constants are 1-2 orders of magnitude higher than those obtained for gamma-CyD and depend on the characteristics of the oligomer batch used. The concentration profiles of the species in solution evidence the progressive monomerization of DOX with increasing oligomer concentration. Confocal fluorescence imaging and spectral imaging showed a similar drug distribution within the MCF-7 cell line incubated with either DOX complexed to p gamma-CyD or free DOX. In both cases DOX is taken up into the cell nucleus without any degradation.

The synthesis of [PhC(NSiMe(3))(2)]Y-2(mu-Cl)(2)Li . 2THF (1) from YCl3 . 3.5THF and [PhC(NSiMe(3))(2)]Li, which is easily transformed into [PhC(NSiMe(3))(2)]2YCl . THF (2), provides a useful entry into the chemistry of several bis(N,N'-bis(trimethylsilyl)benzamidinato)yttrium complexes. Those prepared from 2 by chloride metathesis include [PhC(NSiMe(3))(2)](2)YR (R = BH4 . THF (3), N(SiMe(3))(2) (4), 2,6-(CMe(3))(2)-4-MeOC(6)H(2) (5), (mu-Me)(2)Li . TMEDA (6) (TMEDA = N,N,N',N'-tetramethylethylenediamine), CH(2)Ph . THF (7), CH(SiMe(3))(2) (8)). Similar to 8, [p-MeOC(6)H(4)C(NSiMe(3))(2)]2YCH(SiMe(3))(2) (8(OMe)) could be prepared starting from [p-MeOC(6)H(4)C(NSiMe(3))(2)]2YCl . THF (2(OMe)). Hydrogenolysis (4 atm) of 8 and 8(OMe) affords dimeric hydrides {[p-X-C6H4C(NSiMe(3))(2)]Y-2(mu-H)}(2) (X = H (9), X = MeO (9(OMe))). The alkyl 8(OMe) and the hydride 9 have been characterized by an X-ray diffraction structure determination. Sterically the bis(N,N'-bis(trimethylsilyl)benzamidinate) ligand system resembles more the bis(pentamethylcyclopentadienyl) than the bis(cyclopentadienyl) ligand set. However, INDO/1 semi-empirical MO studies indicate that the electronic properties of [HC(NH)(2)]2YCH3 (used as a model for bis(benzamidinato)yttrium alkyl complexes) are rather different from [C5H5]2YCH3. The yttrium atom in [HC(NH)(2)]2YCH3 is considerably more positively charged than in [C5H5]2YCH3. The resulting strong ionic character of the bis(benzamidinate) system is held responsible for the absence of agostic interactions and H/D exchange and the low hydrogenolysis rate observed.

The investigation of the PtCl2(diphosphine) + SnI2 and PtI2(diphosphine) + SnCl2 systems of catalytic importance (where diphosphines are 2, 3-bis(diphenylphosphino)butane and 2,4-bis(diphenylphosphino)pentane) by NMR in solution has been carried out. Novel PtI(SnCl3)-(diphosphine) and PtI(SnCl2I)(diphosphine) complexes were formed as a consequence of the halide exchange reaction. The selective formation of PtI(SnCl3)[2,4-bis(diphenylphosphino)-pentane] was observed in the reaction of Pt(SnCl3)[2,4-bis(diphenylpho sphino)pentane] and 0.5 SnCl2 and 0.5 SnI2. PtI(SnCl3)[2,4-bis(diphenylphosphino)pentane], the first platinum complex which contains a chiral chelating diphosphine and SnCl3 ligand, was structurally characterized by X-ray diffraction.

The synthesis, crystal and molecular structure and catalytic activity in epoxidation reactions of new dinuclear nickel(II)-complexes, octahedral mu-diacetato-mu-[2,6-bis[N-2-(2'-pyridylethyl) formimidoyl]phenolato]bisnickel(II). perchlorate . methanol (6) and square planar (mu-hydroxo-mu-[2,6-bis[N-((S)-1-benzyl-2-yl-pyrrolidine)formimidoyl]phenolato]bisnickel(II)-bisperchlorate (7), are described. For the preparation of 7 a new 5-step route for homochiral bisamine (S)-benzyl-2-aminomethyl-pyrrolidine (19) was developed starting from (S)-proline. Epoxidation of unfunctionalized alkenes with sodium hypochlorite and tert-butyl hydroperoxide as terminal oxidants was effectively catalyzed with bisnickel(II)-complexes 6 and 7, and a turnover of 165 was reached using trans-beta-methylstyrene (34). The epoxidations probably proceed via a radical intermediate (such as OCl .) and no enantioselectivity is obtained under phase transfer conditions. In epoxidation reactions employing tert-butyl hydroperoxide as terminal oxidant a turnover of 43 was obtained with trans-stilbene (30) as substrate. Unexpectedly in the case of styrene (29) 1,2-bis-(tert-butylperoxy)ethylbenzene (59) was isolated as the major product.

The authors are grateful to the Royal Society (RS International Joint Project 2010/R3), Deutsche Forschungsgemeinschaft (project 436 RUS 113/967/0-1 R), the Russian Foundation for Basic Research (project 10-03-00735), the Presidium of the Russian Academy of Sciences (projects 7.17, 8.14 and P-8), and to the Siberian Branch of the Russian Academy of Sciences (project 105) for funding. The first charge-transfer complexes of tetrathiafulvalene (1) with 1,2,5-chalcogenadiazole derivatives, i.e. with [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (2) and 3,4-dicyano-1,2,5-telluradiazole (3), were designed, prepared in the form of air and thermally stable single crystals and structurally defined by X-ray diffraction as 1-2 and 1.3(2), respectively. Starting compound 2 (effective electron acceptor with potentially broad application in the field) was synthesized by a new efficient one-pot method from 3,4-diamino-1,2,5-oxadiazole and disulfur dichloride. The electronic structure of complexes 1.2 and 1.3(2) and thermodynamics of their formation were studied by means of DFT and QTAIM calculations and UV-Vis spectroscopy. The electrical properties of single crystals of the complexes were investigated revealing semiconductor properties with an activation energy of 0.34 eV for 1.2 and 0.40 eV for 1.3(2). Polycrystalline films of the complexes displayed photoconductive effects with increased conductivity under white-light illumination. Postprint

Yilmaz, Veysel/0000-0002-2849-3332; Golcu, Aysegul/0000-0001-5228-1682 WOS: 000316642900041 PubMed: 23434229 Two new platinum(II) complexes, trans-[Pt(2-mpy)(2)]center dot 4H(2)O (1) and [PtCl(2-pyc)(2-hmpy)]center dot H2O (2), where 2-hmpy = 2-(hydroxymethyl)pyridine, 2-mpy = deprotonated 2-hmpy and 2-pyc = pyridine-2-carboxylate, have been synthesized and characterized by elemental analysis, IR, NMR, and X-ray crystallography. The DNA binding affinities of these complexes for Fish Sperm DNA (FS-DNA) were investigated using fluorescence, viscosity, thermal denaturation and gel electrophoresis measurements. Fluorescence analysis indicates that complex 1 binds to DNA by a single intercalative mechanism, while complex 2 exhibits two types of interactions such as intercalation and covalent binding. Gel electrophoresis assay demonstrates ability of the complexes to cleavage the supercoiled 0311322 plasmid DNA. The in vitro cytotoxicities of both complexes were preliminarily evaluated and the cytotoxicity of complex 1 against the human lung cancer cells (H1299) is similar to oxaliplatin, but higher than transplatin and carboplatin. (C) 2013 Elsevier Ltd. All rights reserved. Uludag UniversityUludag University We thank Uludag University for the financial support given to the project.

We study chemical reactivity, energetics, interactions and structure of neutral and ionic species - in the gas phase- of fundamental, biological and technological relevance. For this purpose, we use a number of experimental (Fourier Transform Ion Cyclotron Resonance FT-ICR; calorimetry of combustion; Knudsen's effusion; photoelectron-photoion coincidence spectroscopy PEPICO) and theoretical techniques. The combination of the experimental results with those obtained by means of quantum-mechanic calculations (ab-initio, DFT) allow us to: i) obtain quantitative information on thermodynamic and kinetic of a variety of reactions in the phase gas, ii) determine interesting and novel relationship of reactivity-chemical structure, iii) determine the thermodynamic stability of neutral and ionic species, iv) to discover new species and new types of chemical bonds. Revisión por pares

The vanadium imido complex ArNVCl 3 ( 2 ) (Ar = 2,6-C 6 H 3 ( 1 Pr) 2 ) can be converted to the half-sandwich imido vanadium complex CpV(NAr)Cl 2 ( 3 ) by reaction with CpSiMe 3 . Reaction of 3 and of CpV(N- p -tolyl)Cl 2 ( 1 ) with alkylating reagents did not allow the isolation of the pure dialkyl complexes but showed extensive reduction of vanadium. Reaction of 1 with AlMe 3 leads to the formation of a mixture of diamagnetic dimeric, imido-bridged complexes (CpV) 2 ( μ -N- p -tolyl) 2 MeR (R = Me or Cl), which can be converted to the pure chloro compound [CpV( μ -N- p -tolyl)Cl] 2 ( 4 ) by reaction with HCl. Dimerization is prevented when the more bulky ArN ligand is used. Alkylation of 4 with MeLi proceeds cleanly to give the methyl compound [CpV( μ -N- p -tolyl)Me] 2 ( 5 ). The molecular structures of the formally vanadium(IV) complexes 4 and 5 have been obtained, showing a planar cyclovanadazene core with a vanadium-vanadium single bond and VCl and VC Me bond lengths that are characteristic of V(V) compounds. Compound 5 reacts with CO by insertion in the VC bond, but no reaction is observed with other small unsaturated molecules or Bronsted acids. The 51 V NMR chemical shifts of the new complexes are reported and compared with the chemical shifts of known imido vanadium complexes.

[Aims] The recent discovery of methyl isocyanate (CH3NCO) in Sgr B2(N) and Orion KL makes methyl cyanate (CH3OCN) a potential molecule in the interstellar medium. The aim of this work is to fulfill the first requirement for its unequivocal identification in space, i.e. the availability of transition frequencies with high accuracy., [Methods] The room-temperature rotational spectrum of methyl cyanate was recorded in the millimeter wave domain from 130 to 350 GHz. All rotational transitions revealed A-E splitting owing to methyl internal rotation and were globally analyzed using the ERHAM program., [Results] The data set for the ground torsional state of methyl cyanate exceeds 700 transitions within J′′ = 10−35 and K"a= 0−13 and newly derived spectroscopic constants reproduce the spectrum close to the experimental uncertainty. Spectral features of methyl cyanate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of methyl cyanate are provided., The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007−2013)/ERC-2013-SyG, Grant Agreement n. 610256 NANOCOSMOS, Ministerio de Ciencia e Innovación (Grants CTQ2013-40717-P, AYA2012-32032, and Consolider-Ingenio 2010 CSD2009-00038 program ASTROMOL) and Junta de Castilla y León (Grant VA175U13). J.-C. G. thanks the Centre National d’Études Spatiales (CNES) and the CNRS program Physique et Chimie du Milieu Interstellaire (PCMI) for financial support. C.B. and E.R.A. also wish to thank the Ministerio de Ciencia e Innovacion for an FPI grant (BES-2011-047695 y BES-2014-067776). MINECO/ICTI2013-2016/CTQ2013-40717-P

The new compounds {M(eta-C(5)R(5))[eta-CPh(NSiMe(3))(2)]]Cl-2} (where R = H, M = Ti, Zr, Hf or R = Me, M = Ti or Zr), are described. The crystal structures of {M(eta-C(5)R(5))([eta-CPh(NSiMe(3))(2)]Cl-2} (R = H, M = Zr or Hf) have been determined. The compound {Zr(eta-C5H5)[eta-CPh(NSiMe(3))(2)]Cl-2} acts as a co-catalyst for the polymerisation of ethylene and propene.

The conformational disorder compatible with the highly extended chains found in mesomorphic poly(ethylene terephthalate) has been studied by Monte Carlo calculations on model oligomers confined inside cylindrical tubes. The distribution of torsional angles for such extended chains is characterized by O-C-C-O bonds being always in the trans domain, while the C-O-C-C bonds show an approximately similar probability of being found in trans and gauche states, the probability maxima being centered at 90 degrees and -90 degrees in the latter cases. At variance with the torsional angles of the O-C-C-O and the ester bonds, always very close to 180 degrees, the distributions for all other torsional angles show flat and broad probability maxima, indicating the possibility of substantial deviations from the average value inside each domain. This is also true for the fictitious O-(CC)-C-...-O bonds across the phenylene rings, for which a nearly trans geometry is preferred in extended conformations.

A variety of well-defined early transition metal complexes were tested as catalyst for the hydroboration of 1-hexene using catecholborane as boration agent. The variations applied concerned both metal (Y, La, Ti, Zr) and spectator ligand system (bis(cyclopentadienyl), bis(pentamethylcyclopentadienyl), bis(benzamidinate), cyclopentadienyl-benzamidinate, cyclopentadienyl-aryloxy, and cylopentadienyl-amido). Most systems proved to be catalytically active (anti-Markovnikov regioselectivity, side reactions negligible), but the observed activity was in all cases lower than reported for Cp*2LaCH(SiMe3)2 [1]. Inactivation of the catalyst by catecholborane or Lewis base-metal complex induced disproportionation of catecholborane appeared to compete effectively with the catalytic conversion, thus leading to inefficient catalytic performance and complicated product mixtures. Systems with bidentate, cyclopentadienyl ligands with a pending anionic (aryloxy, amido) function showed a moderate catalytic activity but excellent catalyst stability and open up interesting perspectives for further exploration.

International audience; Henry's law constant is a significant parameter in description of the phase behaviour of the dilute aqueous solutions. In this communication, a reliable empirical method is proposed for representing/predicting the Henry's law constant (HLC) of 1816 non-electrolyte organic compounds from different chemical families in water within the (293.15 to 298.15) K temperature range. The normal boiling point temperature, critical pressure, number of phenol/enol/carboxyl OH, hydrogen atoms attached to carbon atom, aliphatic groups attached to OH bond, hydrogen atoms attached to carbon atom with hybridisation sp(3) in each compound, and existences of C-N and C-O bonds in each molecule are applied as the parameters of this correlation. The overall absolute average deviation observed on the calculated and predicted Henry's constant values with respect to experimental ones is about 10% (based on logarithm of HLC values). The simple correlation presented here can be easily applied for rapid estimation of the Henry's law constants of many of commonly-used organic compounds in water at specified conditions.

Chlorogenic acid (5-caffeoylquinic acid) is a hydrophilic phenolic compound with antioxidant properties. Because of its high polarity, these properties may be altered when formulated in oil-based food. There is therefore an interest in trying to protect the natural antioxidant by molecular encapsulation. Amylose, the linear fraction of starch with essentially alpha(1-4) linkages, is well known for its ability to form semi-crystalline complexes with a variety of small ligands. Monoacyl lipids, as well as smaller ligands such as alcohols or flavor compounds, are able to induce the formation of left-handed amylose single helices. In contrast, chlorogenic acid is a bulky molecule whose topology requires the amylose helix to be distorted, which could prevent amylose complexation. An innovative strategy has been developed to overcome this problem by grafting an aliphatic chain onto chlorogenic acid then trapping this chain in the helical cavity. The lipophilization reaction was used to obtain a palmitoyl chlorogenic acid derivative and the amylose-palmitoyl chlorogenic acid assemblies were studied by X-ray diffraction, differential scanning calorimetry and NMR to elucidate the interaction. The results showed that such interactions between amylose and palmitoyl chlorogenic acid are effective. (C) 2012 Elsevier Ltd. All rights reserved.

Direct reaction of copper(I) chloride with 2-mercaptopyrimidine (pmtH) in the presence of the triphenylphosphine (tpp) in 1: 1: 2 M ratio forms the mixed ligand Cu(I) complex with formula [CuCl(tpp)(2)(pmtH)] (1). The dimeric {[Cu(tpp)(pmt)](2) 0.5(MeOH)} (2) complex was derived from the reaction of 1 with twofold molar amount of sodium hydroxide. However, the reaction of copper(II) sulfate or nitrate with pmtH and tpp in 1: 2: 2 M ratio, unexpectedly results in the formation of the [CuSH(tpp)(2)(pmtH)] (3) complex. Further studies have shown that the [Cu(tpp)(2)(pmt)] (4) complex is formed by reacting copper(II) acetate with pmtH in the presence of tpp in 1: 2: 2 M ratio, while in the absent of tpp, the Cu(CH3COO)(2) or CuSO4 is found to oxidizes pmtH to its corresponding disulfide (pmt)(2). For comparison the mixed ligand silver(I) chloride or nitrate complexes with formula [AgCl(tpp)(2)(pmtH)] (5) or [Ag(NO3)(tpp)(2)(pmtH)] (6) are also synthesized by reacting of the AgCl or AgNO3 with pmtH and tpp in 1: 2: 2 M ratio. The complexes have been characterized by elemental analyses, m. p., vibrational spectroscopy (mid-, far-FT-IR and Raman), H-1 NMR, UV-Vis, ESI-MS, TG-DTA spectroscopic techniques and single crystal X-ray crystallography at ambient conditions. Photolysis of 1-6, was also studied and the results showed formation of triphenylphosphine oxide. The complexes 1-6, were used to study their influence upon the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX) experimentally and theoretically. The binding of 1-4 with LOX was also investigated by saturation transfer difference H-1 NMR experiments (STD). (C) 2011 Elsevier B. V. All rights reserved. Inorganica Chimica Acta

The title compound, C9H13Br2ClNTe, was synthesized by reacting [2-(dimethylaminomethyl) phenyl] tellurium(II) chloride with Br-2. As a consequence, the Cl and Br atoms are not well ordered but distributed over the three possible positions such that the overall stiochiometry is two Br atoms and one Cl atom. The scrambling of the Br and Cl atoms indicates a small energy barrier for the exchange process between the apical and equatorial positions. Overall, the Te atom geometry is slightly distorted square pyramidal (tau = 0.052 for the major component). However, there is a weak secondary interaction between the Te atoms and the disordered Br/Cl atoms of a nearby molecule. The Te-Br and Te-Cl distances in both disorder components fall into two groups; a longer distance for the Br/Cl involved in this secondary interaction [2.6945 (17) angstrom for Br and 2.601 (9) angstrom for Cl] and shorter bond distances to the remaining halogen atoms, indicating that this interaction has slightly weakened the Te-X bond, as is the case in the previously reported tribromido structure [Singh et al. (1990). J. Chem. Soc. Dalton Trans. pp. 907-913]. Otherwise, the metrical parameters in the two structures are not significantly different. An intermolecular C-H center dot center dot center dot Br interaction occurs.

Treatment of six-coordinate (5,10,15-triphenylcorrole)dihydroxyphosphorus(V) [P(TPC)(OH)2] with trifluoroacetic acid (TFA) in CH2Cl2 for 30 min at room temperature followed by recrystallization gave stable five-coordinate (5,10,15-triphenylcorrole)oxophosphorus(V) [P(TPC)O] in quantitative yield. The formation of [P(TPC)O] from [P(TPC)(OH)2] in the presence of TFA was also monitored by NMR, absorption and fluorescence spectroscopic titration studies. The structure of the isolated [P(TPC)O] was confirmed by X-ray crystallography. In [P(TPC)O], the corrole ring is distorted, and the PV ion is displaced by 0.456 angstrom from the N4 plane towards the axial oxygen atom. This is unlike six-coordinate (5,10,15-triphenylcorrole)dimethoxyphosphorus(V) [P(TPC)(OCH3)2], in which the PV ion lies in the porphyrin plane. NMR, absorption and fluorescence spectroscopy and electrochemical studies indicate that [P(TPC)O] exhibits interesting and distinct properties, which differ from the six-coordinate [P(TPC)(OCH3)2]. Attempts to reduce the PV complex [P(TPC)O] to its corresponding PIII complex by treating it with LiAlH4 resulted in the formation of six-coordinate (5,10,15-triphenylcorrole)dihydridophosphorus(V) [P(TPC)H2].

The 7-coordinated Re(III) complex [Re(terpy)2OH]2+, where terpy = 2,2?:6?,6?- terpyridine, has been synthesized and characterized. Preparation of this complex from [RevO2(pyridine)4]+ occurs via a reduction/substitution route utilizing 2 molar equiv of terpyridine. The concomitant production of ReO4 - implies the presence of a disproportionation component in the preparative reaction. Replacement of the coordinated hydroxo ligand by Cl- or NCS- to generate respectively the [Re(terpy)2Cl]2+ or [Re(terpy)2NCS]2+ complex proceeds much more rapidly at low pH. The X-ray crystal structure analyses of all three novel complexes are reported: [Re(terpy)2OH](PF6)2·H2O crystallizes in the triclinic space group P1? with a = 9.099(1) Å, b = 10.781(2) Å, c = 17.438(3) Å, ? = 82.87(1)°, ? = 88.85(1)°, ? = 86.83(1)°, V = 1694.6(4) Å3, and Z = 2. [Re(terpy)2Cl](PF6)2 crystallizes in the monoclinic space group P21/c with a = 9.257(2) Å, b = 19.597(5) Å, c = 17.899(5) Å, ?= 94.85(2)°, V = 3235(1) Å3, and Z = 4. [Re(terpy)2-NCS](SCN)2*1/2H2O crystallizes in the triclinic space group P1? with a = 10.067(4) Å, b = 11.121(2) Å, c = 15.133(7) Å, ? = 89.63(3)°, ? = 80.04(4)°, ? = 75.46(3)°, V = 1614(1) Å3, and Z = 2. The solution structure is fully determined by proton NMR and is shown to be similar to that in the solid state with two equivalent, but asymmetric, terpy ligands. In addition, the [Re(terpy)2X]2+ complexes are characterized by elemental analysis, UV-vis, IR, and mass spectroscopy, and/or thin-layer chromatography. A preliminary kinetic study of the substitution reaction of [Re(terpy)2OH]2+ to yield [Re(terpy)2NCS]2+ indicates that the hydroxy complex is involved in a rapid protonation equilibrium to yield a reactive species which then reacts with SCN- in a rate determining step. Derived equilibrium and rate constants at 25°C and ? = 1.00 M are pKa = 1.4(8) and k = 45(4) M-1 s-1. The reverse reaction rate is insignificant under the conditions utilized.

The mechanism of the asymmetric hydrogenation of methyl (Z)-2-acetamidocinnamate (mac) catalysed by [Rh(MonoPhos)(2)(nbd)]SbF(6) (MonoPhos: 3,5-dioxa-4-phosphacyclohepta[2,1-a:3,4-a']dinaphthalen-4-yl)dimethylamine) was elucidated by using (1)H, (31)P and (103)Rh NMR spectroscopy and ESI-MS. The use of nbd allows one to obtain in pure form the rhodium complex that contains two units of the ligand. In contrast to the analogous complexes that contain cis, cis-1,5-cyclooctadiene (cod), this complex shows well-resolved NMR spectroscopic signals. Hydrogenation of these catalyst precursors at 1 bar total pressure gave rise to the formation of a bimetallic complex of general formula [Rh(MonoPhos)(2)](2)(SbF(6))(2); no solvate complexes were detected. In the dimeric complex both rhodium atoms are ligated to two MonoPhos ligands but, in addition, each rhodium atom also binds to one of the binaphthyl rings of a ligand that is bound to the other rhodium metal. Upon addition of mac, a mixture of diastereomeric complexes [Rh(MonoPhos)(2)(mac)]SbF(6) is formed in which the substrate is bound in a chelate fashion to the metal. Upon hydrogenation, these adducts are converted into a new complex [Rh(MonoPhos)(2){mac(H)(2)}]SbF(6) in which the methyl phenylalaninate mac(H)(2) is bound through its aromatic ring to rhodium. Addition of mac to this complex leads to displacement of the product by the substrate. No hydride intermediates could be detected and no evidence was found for the involvement at any stage of the process of complexes with only one coordinated MonoPhos. The collected data suggest that the asymmetric hydrogenation follows a Halpern-like mechanism in which the less abundant substrate-catalyst adduct is preferentially hydrogenated to phenylalanine methyl ester.

Two functional groups can be delivered at once to organo-rare earth complexes, (L)MR(2) and (L)(2)MR (M = Sc, Y; L = ({1-C(NDippCH(2)CH(2)N)}CH(2)CMe(2)O), Dipp = 2,6-(i)Pr(2)-C(6)H(3); R = CH(2)SiMe(3), CH(2)CMe(3)), via the addition of E-X across the metal-carbene bond to form a zwitterionic imidazolinium-metal complex, (L(E))MR(2)X, where L(E) = {1-EC(NDippCH(2)CH(2)N)}CH(2)CMe(2)O, E is a p-block functional group such as SiR(3), PR(2), or SnR(3), and X is a halide. The "ate" complex (L(Li))ScR(3) is readily accessible and is best described as a Li carbene adduct, ({1-Li(THF)C(NDippCH(2)CH(2)N)}CH(2)CMe(2)O)Sc(CH(2)SiMe(3))(3), since structural characterization shows the alkoxide ligand bridging the two metals and the carbene Li-bound with the shortest yet recorded Li-C bond distance. This can be converted via lithium halide-eliminating salt metathesis reactions to alkylated or silylated imidazolinium derivatives, (L(E))ScR(3) (E = SiMe(3) or CPh(3)). All the E-functionalized imidazolinium complexes spontaneously eliminate functionalized hydrocarbyl compounds upon warming to room temperature or slightly above, forming new organic products ER, i.e., forming C-Si, C-P, and C-Sn bonds, and re-forming the inorganic metal carbene (L)MR(X) or (L)(2)MX complex, respectively. Warming the tris(alkyl) complexes (L(E))MR(3) forms organic products arising from C-C or C-Si bond formation, which appears to proceed via the same elimination route. Treatment of (L)(2)Sc(CH(2)SiMe(3)) with iodopentafluorobenzene results in the "reverse sense" addition, which upon thermolysis forms the metal aryl complex (L)(2)Sc(C(6)F(5)) and releases the iodoalkane Me(3)SiCH(2)I, again facilitated by the reversible functionalization of the N-heterocyclic carbene group in these tethered systems.

The compound (PPh4)(2)[Fe-III(CN)(5)(im)]center dot 2H(2)O (1) together with its C-13 labeled analogue have been synthesized (where im is imidazole) and characterized by UV/Vis, LD, IR, Raman and resonance Raman spectroscopy both in solution, powder and single crystalline form. The low spin state of the metal center, Fe-III, was confirmed by MCD, EPR and Fe-57 Mossbauer spectroscopies. Polarized Raman spectroscopic studies on a single crystal of 1 show the strong dependence of the stretching cyano ligand vibrations on crystal orientation relative to the direction of laser polarization and allows for assignment of all CN vibrational modes. Raman, UV/Vis absorption, LD and MCD spectroscopy both in the solid state and in solution state allowed for the discrimination of the effect of protonation of the imidazole ligand and hydrogen bonding to the cyano ligands on the complex. The combined spectroscopic data demonstrates that in addition to the protonation state of the imidazole, hydrogen bonding interactions with the cyano ligands both in the solid state as well as in solution have a profound influence on the electronic properties of 1. (C) 2011 Elsevier B.V. All rights reserved.

New amphiphilic and spin-labile Mn-III complexes based on dianionic N4O2-hexadentate sal(2)trien or sal(2)bapen ligands, which contain OC6H13, OC12H25, or OC18H37 alkoxy substituents at different positions of the salicylidene unit were prepared (H(2)sal(2)trien = N, N"'-bis(salicylidene)-1,4,7,10-tetraazadecane, H(2)sal(2)bapen = N, N"'-bis(salicylidene)-1,5,8,12-tetraazadodecane). According to electrochemical measurements, these complexes undergo two (quasi) reversible redox processes. Temperature-dependent magnetic measurements revealed a high-spin configuration for all sal(2)trien complexes (S = 2) and gradual spin crossover for sal(2)bapen complexes from high to low spin (S = 1). The chain length strongly influences the spin crossover, as C-18-functionalization stabilizes the low spin state at much higher temperatures than shorter alkyl chains. Moreover, long alkyl chains allow for spontaneous self-assembly of the molecules, which was investigated in single crystals and in Langmuir-films at the air-water interface. Long alkyl chains (C-12 or C-18) as well as a mutual syn-orientation of these molecular recognition sites were required for the Langmuir monolayers to be stable. ERA-net Chemistry Swiss National Science Foundation Alfred Werner Foundation

We describe the synthesis of two novel poly(1,4-arylene-2,5-thienylene)s P1 and P2 containing benzo[c][2,1,3]thiadiazole monomeric units via Suzuki-Miyaura polymerization of a thiophene diboronic ester with aryl diiodides. The use of a catalyst complex consisting of Pd(OAc)(2) in combination with the electron-rich biaryl phosphine S-Phos resulted in efficient polymerization reactions. The polymers synthesized, P1 and P2, were characterized by UV-vis spectroscopy and cyclic voltammetry. Theoretical calculations and electrochemical measurements on P1 suggested a favorable position of the molecular orbitals for employment in polymer solar cells in combination with PCBM. Devices containing P1:PCBM 1:2 in the active layer showed an efficiency of 1.2% by simple spin casting from chloroform. (C) 2011 Elsevier B.V. All rights reserved.

Reactions of (2-formylphenyl)mercury(II) bromide 10 with primary amines give mono-, bis- and tris-Schiff base derivatives (11-18). Structures of the synthesized compounds show the presence of five-membered intramolecular Hg center dot center dot center dot N interaction. Luminescence studies of the compounds have been performed. Attempts to use the synthesized compounds for binding neutral donor molecules or fluoride ions were unsuccessful. (C) 2011 Elsevier B. V. All rights reserved.

Treatment of [Cp*MoCl4], 1 (Cp* = η5-C5Me5), with [LiBH4.thf] in toluene at −40 °C, followed by thermolysis with [(thf)Li{CH(PPh2–BH3)2}] results in the formation of a new class of phosphido bridged molybdaborane [(Cp*Mo)2B4H7(μ-PPh2)], 2 which has been characterized crystallographically. In addition, the above reaction also produces known [(Cp*Mo)2B5H9], 3 and an unusual molybdaborane [(Cp*Mo)2B5H8(O i Pr)], 4 ( i Pr = –CH(CH3)2). All the new compounds have been characterized in solution by 1H, 11B, 13C, 31P NMR spectroscopy and the structural types were unambiguously established by X-ray crystallographic analysis of compounds 2 and 4. Treatment of [Cp*MoCl4] (Cp* = η5-C5Me5), with [LiBH4.thf] in toluene at −40 °C, followed by thermolysis with [(thf)Li{CH(PPh2-BH3)2}] results in the formation of a new class of phosphido bridged molybdaborane [(Cp*Mo)2B4H7(μ-PPh2)] which has been characterized crystallographically.

The isolation of pure [2-(phenylazo)phenyl-C,N']tellurium(IV) tribromide (6) has been achieved by modifying the reported procedure, which involved transmetalation of [2-(phenylazo)phenyl-C, N']mercury(II) chloride (7) with TeBr(4). The mixed-valent derivative bis[2-(phenylazo)phenyl-C, N']ditellurium dichloride (19), incorporating both a divalent and a tetravalent tellurium, was obtained serendipitously during the reduction of [2-(phenylazo)phenyl-C,N']tellurium(IV) trichloride (16) with hydrazine hydrate. Bis[2-(phenylazo)phenyl-C,N']telluride (10) has been synthesized by the ortho-lithiation route. Telluride 10, on treatment with SO(2)Cl(2) and Br(2), underwent oxidative addition to give the expected Te(IV) halogenated products bis[2-(phenylazo)phenyl-C,N']tellurium(IV) dichloride (13) and bis[2-(phenylazo)phenyl-C,N']tellurium(IV) dibromide (11), respectively. However, a similar reaction of 10 with 12 resulted in the formation of an unexpected telluronium cation, iodobis[2-(phenylazo)phenyl-C,N']telluronium triiodide (14), and [2-(phenylazo)phenyl-C,N']tellurenenyl(II) iodide (12). Alkaline hydrolysis of 16 under reflux conditions resulted in the formation of monomeric [2-(phenylazo)phenyl-C,N']tellurinic acid (20) and its sodium salt (21) as a cocrystal. Bis[[2-(phenylazo)phenyl-C,N']tellurium]-oxide (22) was obtained from the hydrolysis of [2-(phenylazo)phenyl-C,N']tellurium(II) chloride (17). The reaction of 13 with an alkaline solution resulted in the formation of the corresponding bis[2-(phenyl-azo)phenyl-C,N']tellurium(IV) oxide (23) and dichlorobis[2-(phenylazo)phenyl-C,N']tellurium(IV) oxide (24). The identity of all the derivatives was confirmed by multinuclear NMR ((1)H, (13)C, (125)Te) and FT-IR spectroscopy, elemental analysis, and ESI-MS. The structures for tellurium derivatives 6, 10-14, 17, 19, 20-23, and 23A were also confirmed by X-ray crystallography. Density functional theory (DFT) was utilized for optimizing the geometries of 11, 13, and 14 to examine the possibility of a four-membered intramolecular Te center dot center dot center dot N interaction.

Diphosphinite ligand, [Ph(2)POC(6)H(4)OPPh(2)] (1), is obtained by reacting chloro diphenylphosphine, with 1,4-dihydroxy benzene in presence of triethylamine. Treatment of 1 with elemental sulfur or selenium resulted in the formation of bis(chalcogenide) derivatives, [Ph(2)(E)POC(6)H(4)OP(E)Ph(2)] (2, E = S; 3, E = Se) in almost quantitative yield. The binuclear complex [{(eta(6)-p-cymene)RuCl(2)}(2)(Ph(2)POC(6)H(4)OPPh(2))] (4) is produced in the reaction between [Ru(eta(6)-p-cymene)Cl(2)](2) and diphosphinite 1. Similarly the reaction of 1 with [Rh(COD)Cl](2) afforded a binuclear complex [{(COD)RhCl}(2)(Ph(2)POC(6)H(4)OPPh(2))] (5), whereas the macrocyclic complex [{(CO)RhCl}(Ph(2)POC(6)H(4)OPPh(2))](2) (6) is isolated in the reaction of 1 with 0.5 equiv of [RhCl(CO)(2)](2). Compound 1 on treatment with [Pd(COD)Cl(2)] or [PdCl(2)(SMe(2))(2)] in 1:1 molar ratio produced the chloro-bridged binuclear complex [{(PPh(2)O)Pd(mu-Cl)(PPh(2)OH)}(2)] (7) through P-O bond cleavage. Treatment of 1 with two equivalents of CuI in dichlormethane/acetonitrile (1:1) afforded a coordination polymer, [{Cu(2)(mu-I)(2)(Ph(2)POC(6)H(4)OPPh(2))}(infinity)] (8) in moderate yield. The binuclear complex, [{AuCl}(2)(mu-Ph(2)POC(6)H(4)OPPh(2))] (9) is obtained in the reaction of compound 1 with two equiv of AuCl(SMe(2)), where the ligand exhibits bridged bidentate mode of coordination. The molecular structures of 1-4, and 6 are determined by X-ray diffraction studies. (C) 2011 Elsevier B.V. All rights reserved.

Oxidative addition of bis[2-(4,4-dimethyl-2-oxazolinyl)phenyl] diselenide to Pd(PPh(3))(4) provided two different mononuclear palladium selenolato complexes, Pd(Se boolean AND N)(PPh(3))Cl (4) [Se boolean AND N = chelating 2-(4,4-dimethyl-2-oxazolinyl)phenylselenolate] and Pd(Se boolean AND N)(Se boolean AND N*)(PPh(3)) (5) [Se boolean AND N = chelating, Se boolean AND N* = non-chelating 2-(4,4-dimethyl-2-oxazolinyl)phenylselenolato ligand] in dicholoromethane and toluene respectively. Complex 4 has also been synthesized by the oxidative addition of 2-(4,4-dimethyl-2-oxazolinyl)phenylselenenyl chloride to Pd(PPh(3))(4). The bromo and iodo analogs of 4 (9 and 10) were similarly synthesized by the oxidative addition of 2-(4,4-dimethyl-2-oxazolinyl) phenylselenenyl bromide and iodide, respectively to Pd(PPh(3))(4). The oxidative addition of 2-(N,N-dimethylaminomethyl)phenylselenenyl bromide and iodide to Pd(PPh(3))(4) afforded mononuclear palladium selenolate complexes, Pd(Se boolean AND N)(PPh(3)) X (13 and 14) [Se boolean AND N = chelating 2-(N,N-dimethylaminomethyl)phenylselenolate, X = Br: 13, X = 1:14]. The reactions of bis[2-(4,4-dimethyl-2-oxazolinyl) phenyl] diselenide and bis[2-(N, N-dimethylaminomethyl) phenyl] diselenide with Pd(COD)Cl(2) provided dinuclear selenolato-bridged complexes [PdCl(Se boolean AND N)](2) (15) [Se boolean AND N = chelating 2-(4,4-dimethyl-2-oxazolinyl)phenylselenolate] and [PdCl(Se boolean AND N)](2) (19) [Se boolean AND N = chelating 2-(N,N-dimethylaminomethyl)phenylselenolate] respectively. The complexes were characterized by elemental analysis and NMR ((1)H and (77)Se) spectroscopy. Complexes 4 and 5 were also characterized by mass spectrometry. Molecular structures of 4, 5, 9, 14 and 15 have been established by single crystal X-ray diffraction analysis. Complexes 4 and 9 are isomorphous and crystallize in the space group P2(1)/c of the monoclinic system where the selenolato and halo ligands are trans to each other. Complex 5 crystallizes in the space group P2(1)/n of the monoclinic system where one chelating and one non-chelating selenolato ligands are trans to each other. Mononuclear complex 14 and binuclear centrosymmetric complex 15 crystallize in the P (1) over bar space group of the triclinic system. (C) 2011 Elsevier B.V. All rights reserved.

Because of the anisotropies of their electronic charge distributions, many covalently bound halogen atoms have regions of positive electrostatic potential (positive σ-holes) on their outer portions. Through these, the halogens can interact attractively with negative sites. It has sometimes been questioned whether fluorine, the least polarizable halogen, can form halogen bonds, especially in solids. Here we present computational and crystallographic evidence demonstrating that it can indeed do so, in both the gaseous and the solid phases. We show computationally, through a series of examples, that fluorine can have positive σ-holes when linked to strongly electron-withdrawing residues and that it can interact with Lewis bases to form gas phase halogen-bonded complexes. Through statistical analyses of data from the Cambridge Structural Database, we demonstrate that such fluorines do also halogen bond in the solid state, and we show several specific cases of this.

New antimony(III) chloride complexes with heterocyclic thioamides, thiourea (TU), 2-mercapto-5-methyl-benzimidazole (MMBZIM), 3-methyl-2-mercaptobenzothiazole (MMBZT), 2-mercaptopyrimidine (PMT), 2-mercaptopyridine (PYT) of formulae [SbCl3(TU)(2)] (1), [SbCl3(MMBZIM)(2)] (2), [SbCl3(MMBZT)(2)] (3), [SbCl3(PMT)(2)] (4), [SbCl3(mu(2)-S)(PYT)(2)] (5) were synthesized and characterized by elemental analysis, FT-IR and FT-Raman spectroscopies, and TG-DTA analysis. The crystal structure of 5 was also determined by X-ray diffraction. [C10H10Cl3N2S2Sb] (5) crystallizes in space group C2/c, with a = 25.0169(10) angstrom, b = 9.7952(3) angstrom, c = 12.9329(5) angstrom, beta = 109.702(4)degrees, and Z = 8. Crystals of 5 grown from acetonitrile solutions adopt a square-pyramidal geometry. The equatorial plane is formed by three chlorides and one sulfur atom from the thione ligand while the second sulfur is axial. The complexes were evaluated for their biological activities and compared with [SbCl3(MMI)(2)] (6) (MMI = 2-mercapto-1-methylimidazole) and other isostructural ones. The complexes showed moderate cytostatic activity against murine leukemia cells (L1210), murine mammary carcinoma cells (FM3A), human T-lymphocyte (Molt4/C8, CEM), and human cervix carcinoma (HeLa) cells. The chloro and iodo derivatives show better cytostatic activity than the bromo ones. Hellenic Ministry of Education; NATONATO (North Atlantic Treaty Organisation) [PDD(CP)-(CBP.NR.NRCLG 983167)] This research was carried out in partial fulfillment of the requirements for the PhD thesis of I.I.O., under the supervision of S. K. H., under the framework of the graduate program in Bioinorganic Chemistry, coordinated by N.H., at the University of Ioannina. S.K.H., N.H., and I.S.B. would like to acknowledge a NATO grant for the exchange of scientists (PDD(CP)-(CBP.NR.NRCLG 983167). I.I.O. thanks the Hellenic Ministry of Education for a scholarship for postgraduate studies.

Biological systems that can capture and store solar energy are rich in a variety of chemical functionalities, incorporating light-harvesting components, electron-transfer cofactors, and redox-active catalysts into one supramolecule. Any artificial mimic of such systems designed for solar fuels production will require the integration of complex subunits into a larger architecture. We present porous chalcogenide frameworks that can contain both immobilized redox-active Fe4S4 clusters and light-harvesting photoredox dye molecules in close proximity. These multifunctional gels are shown to electrocatalytically reduce protons and carbon disulfide. In addition, incorporation of a photoredox agent into the chalcogels is shown to photochemically produce hydrogen. The gels have a high degree of synthetic flexibility, which should allow for a wide range of light-driven processes relevant to the production of solar fuels. J Am Chem Soc

Cyclopentadienyl and indenyl complexes of the type (eta5-C5H5)Rh(L2) and (eta5-C9H7)Rh(L2) (L2 = chiral diphosphine) have been synthesized and characterized through multinuclear NMR spectroscopy. These formally planar complexes react with methyl iodide to give the pseudotetrahedral methyl derivatives [(eta5-C5H5)Rh(CH3)(L2)]I and [(eta5-C9H7)Rh(CH3)(L2)]I. The stereochemistry of these complexes, as far as the stereogenic metal center is concerned, is inferred by the difference of chemical shifts of the two phosphorus atoms in the P-31 NMR spectra of the diastereomeric pairs. The crystal structure of (R)C,(S)Rh- [ (eta5-C9H7)Rh(Ph2PCH-(CH3)CH2PPh2)(CH3)]BPh4 has been determined and confirms the above assignment. The electrochemical reduction of the same complex is interpreted in terms of a charge-transfer process followed by the homolytic fission of the Rh-CH3 sigma-bond of the electrogenerated rhodium-(II) complex.

The titanium(II) adducts Ti[Me2Si(η5-C5H4)2]L2 [L=CO (1), PMe2Ph (2), CNR (R = 2,6-Me2C6H3) (3) have been made by the reduction of Ti[Me2Si(η5-C5H4)2]Cl2 with HhCl2-activated magnesium in THF in the presence of the ligand L. Mixed titanocene adducts Ti[Me2Si(η5- C5H4)2]LL′ (L=CO; L′=PMe2Ph (4), CNR (5)) can be prepared by the addition of ligands (PMe2Ph, CNR) to hexane solutions of Ti[Me2Si(η5-C5H4)2)(CO)2 exposed to sunlight. The crystal structure of 3 has been determined by X-ray diffraction; the phenyl groups of the isocyanide ligand are almost perpendicular to the reflection plane of the cyclopentadienyl groups., Ministerio de Educación y Ciencia

Gibbs free energies of formation for gas, subcooled liquid, and aqueous solution phases were estimated for all 209 polychlorinated biphenyl (PCB) congeners at 298.15 K and 100 000 Pa. A literature search was conducted to locate experimental data or predicted data for PCBs. Where other data were not available, the standard-state enthalpies of formation of the gas and absolute standard-state entropies of the gas were estimated using the NIST Structures and Properties Database and Estimation Program based on Benson's group additivity method. Resultant Gibbs free energies of formation in aqueous solution, as well as all intermediate quantities used in their calculation, are tabulated. Implications of the data relative to dechlorination are briefly discussed.