5 research outputs found

    Water-Soluble Ruthenium(II) Carbonyls with 1,3,5-Triaza-7-phosphoadamantane

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    4noAs a continuation of our strategy for preparing new Ru(II) precursors with improved water solubility through the introduction of highly water-soluble 1,3,5-triaza-7-phosphoadamantane (PTA) supporting ligands in the coordination sphere, in this work, we address the largely unexplored preparation of Ru(II)-PTA carbonyls. Two complementary synthetic approaches were used: (1) the treatment of a series of neutral Ru(II)-CO-dmso compounds of general formula RuCl2(CO) n(dmso)4- n ( n = 1-3, 1-5) with PTA; (2) the reaction of Ru(II)-PTA complexes with CO. Through the first approach, we obtained and fully characterized seven novel neutral compounds bearing from one to three PTA ligands per Ru atom, namely, the four monocarbonyls, cis, cis, trans-RuCl2(CO)(dmso-S)(PTA)2 (6), trans-RuCl2(CO)(PTA)3 (7), cis, mer-RuCl2(CO)(PTA)3 (8), and trans, trans, trans-RuCl2(CO)(OH2)(PTA)2 (10), and the three dicarbonyls, trans, trans, trans-RuCl2(CO)2(PTA)2 (11), [RuCl2(CO)2(PTA)]2 (12), and cis, cis, trans-RuCl2(CO)2(PTA)2 (13). The less stable, and thus more elusive, species fac-RuCl2(CO)(PTA)3 (9) and cis, cis, cis-RuCl2(CO)2(PTA)2 (14) were also unambiguously identified but could not be obtained in pure form and fully characterized. The complementary synthetic approach, that involved the treatment of the trans- and cis-RuCl2(PTA)4 (15, 16) isomers with CO, afforded only one new Ru(II)-PTA carbonyl, the cationic species cis-[RuCl(CO)(PTA)4]Cl (17). In general, the choice of the solvent was very relevant for obtaining the products with high yield and purity. We were unable to isolate Ru(II)-PTA compounds with more than two carbonyls. The thermodynamically preferred species have CO trans to Cl and two mutually trans PTAs, and only in the dinuclear compound 12 there is a single PTA per Ru atom. Compounds 7 and 17 feature the unprecedented trans-Ru(CO)(PTA) fragment. The X-ray structures of cis, cis, cis-RuCl2(CO)2(dmso)2 (3), 6-8, 10, 11, 13, and 17 are also reported. All compounds are new, are air-stable, and show a good solubility in water ( S from 10 to 165 g·L-1) and, most often, also in chloroform.reservedmixedBattistin, Federica; Balducci, Gabriele; Milani, Barbara; Alessio, EnzoBattistin, Federica; Balducci, Gabriele; Milani, Barbara; Alessio, Enz

    New Cationic and Neutral Ru(II)- and Os(II)-dmso carbonyl Compounds

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    The preparation and structural characterization of three cationic Ru­(II)-dmso carbonyls and of four neutral mono- and dicarbonyl Os­(II)-dmso derivatives is reported. The two monocarbonyl species <i>fac</i>-[Ru­(CO)­(dmso-O)<sub>3</sub>(dmso-S)<sub>2</sub>]­[PF<sub>6</sub>]<sub>2</sub> (<b>11</b>) and <i>cis</i>,<i>cis</i>,<i>cis</i>-[RuCl­(CO)­(dmso-O)<sub>2</sub>(dmso-S)<sub>2</sub>]­[PF<sub>6</sub>] (<b>12</b>) were obtained from the neutral monocarbonyl precursor <i>cis</i>,<i>trans</i>,<i>cis</i>-[RuCl<sub>2</sub>(CO)­(dmso-O)­(dmso-S)<sub>2</sub>] (<b>3</b>) upon stepwise replacement of the chlorides with dmso, that binds in each case through the oxygen atom. The dicarbonyl cationic complex <i>cis</i>,<i>cis</i>,<i>trans</i>-[Ru­(CO)<sub>2</sub>(dmso-O)<sub>2</sub>(dmso-S)­Cl]­[PF<sub>6</sub>] (<b>13</b>) was instead obtained upon treatment of the neutral tricarbonyl precursor <i>fac</i>-[RuCl<sub>2</sub>(CO)<sub>3</sub>(dmso-O)] (<b>8</b>) with AgPF<sub>6</sub> in the presence of DMSO: replacement of a Cl<sup>–</sup> with a dmso-O implied also the substitution of one CO ligand by another dmso (that binds through S <i>trans</i> to Cl). The Os­(II) carbonyls <i>trans</i>,<i>trans</i>,<i>trans</i>-[OsCl<sub>2</sub>(CO)­(dmso-O)­(dmso-S)<sub>2</sub>] (<b>17</b>), <i>trans</i>,<i>cis</i>,<i>cis</i>-[OsCl<sub>2</sub>(CO)<sub>2</sub>(dmso-O)<sub>2</sub>] (<b>18</b>), <i>cis</i>,<i>mer</i>-[OsCl<sub>2</sub>(CO)­(dmso-S)<sub>3</sub>] (<b>19</b>), and <i>cis</i>,<i>trans</i>,<i>cis</i>-[OsCl<sub>2</sub>(CO)­(dmso-O)­(dmso-S)<sub>2</sub>] (<b>20</b>) were obtained by treatment of the Os­(II)-dmso precursors <i>trans</i>-[OsCl<sub>2</sub>(dmso-S)<sub><b>4</b></sub>] (<b>14</b>) and <i>cis</i>,<i>fac</i>-[OsCl<sub>2</sub>(dmso-O)­(dmso-S)<sub>3</sub>] (<b>15</b>) with CO. Each one of them is structurally similar to an already known Ru­(II) analog, even thoughin agreement with the expected greater inertness of Os­(II)more forcing reaction conditions were required for their preparation. Interestingly, compound <b>20</b> could not be isolated in pure form, but only as a 1:1 cocrystallized mixture with its precursor <b>15</b>. The dmso ligand is always bound through the oxygen atom when trans to CO. We are confident that the new Ru­(II)- and Os­(II)-dmso carbonyl species described here represent a contribution to expand the pool of complexes bearing some easily replaceable dmso ligands to be used as well-behaved precursors in inorganic synthesis

    New Cationic and Neutral Ru(II)- and Os(II)-dmso carbonyl Compounds

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    The preparation and structural characterization of three cationic Ru­(II)-dmso carbonyls and of four neutral mono- and dicarbonyl Os­(II)-dmso derivatives is reported. The two monocarbonyl species <i>fac</i>-[Ru­(CO)­(dmso-O)<sub>3</sub>(dmso-S)<sub>2</sub>]­[PF<sub>6</sub>]<sub>2</sub> (<b>11</b>) and <i>cis</i>,<i>cis</i>,<i>cis</i>-[RuCl­(CO)­(dmso-O)<sub>2</sub>(dmso-S)<sub>2</sub>]­[PF<sub>6</sub>] (<b>12</b>) were obtained from the neutral monocarbonyl precursor <i>cis</i>,<i>trans</i>,<i>cis</i>-[RuCl<sub>2</sub>(CO)­(dmso-O)­(dmso-S)<sub>2</sub>] (<b>3</b>) upon stepwise replacement of the chlorides with dmso, that binds in each case through the oxygen atom. The dicarbonyl cationic complex <i>cis</i>,<i>cis</i>,<i>trans</i>-[Ru­(CO)<sub>2</sub>(dmso-O)<sub>2</sub>(dmso-S)­Cl]­[PF<sub>6</sub>] (<b>13</b>) was instead obtained upon treatment of the neutral tricarbonyl precursor <i>fac</i>-[RuCl<sub>2</sub>(CO)<sub>3</sub>(dmso-O)] (<b>8</b>) with AgPF<sub>6</sub> in the presence of DMSO: replacement of a Cl<sup>–</sup> with a dmso-O implied also the substitution of one CO ligand by another dmso (that binds through S <i>trans</i> to Cl). The Os­(II) carbonyls <i>trans</i>,<i>trans</i>,<i>trans</i>-[OsCl<sub>2</sub>(CO)­(dmso-O)­(dmso-S)<sub>2</sub>] (<b>17</b>), <i>trans</i>,<i>cis</i>,<i>cis</i>-[OsCl<sub>2</sub>(CO)<sub>2</sub>(dmso-O)<sub>2</sub>] (<b>18</b>), <i>cis</i>,<i>mer</i>-[OsCl<sub>2</sub>(CO)­(dmso-S)<sub>3</sub>] (<b>19</b>), and <i>cis</i>,<i>trans</i>,<i>cis</i>-[OsCl<sub>2</sub>(CO)­(dmso-O)­(dmso-S)<sub>2</sub>] (<b>20</b>) were obtained by treatment of the Os­(II)-dmso precursors <i>trans</i>-[OsCl<sub>2</sub>(dmso-S)<sub><b>4</b></sub>] (<b>14</b>) and <i>cis</i>,<i>fac</i>-[OsCl<sub>2</sub>(dmso-O)­(dmso-S)<sub>3</sub>] (<b>15</b>) with CO. Each one of them is structurally similar to an already known Ru­(II) analog, even thoughin agreement with the expected greater inertness of Os­(II)more forcing reaction conditions were required for their preparation. Interestingly, compound <b>20</b> could not be isolated in pure form, but only as a 1:1 cocrystallized mixture with its precursor <b>15</b>. The dmso ligand is always bound through the oxygen atom when trans to CO. We are confident that the new Ru­(II)- and Os­(II)-dmso carbonyl species described here represent a contribution to expand the pool of complexes bearing some easily replaceable dmso ligands to be used as well-behaved precursors in inorganic synthesis

    Computational Study of Amino Mediated Molecular Interaction Evidenced in N 1s NEXAFS: 1,4-Diaminobenzene on Au (111)

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    Primary amines can interact with neighbor molecules or with a metal substrate via weak bonds involving the electron lone pair of their amino functional group. Near edge X-ray absorption spectra (NEXAFS) on the N 1s edge show that the structure of the empty molecular orbitals localized on the nitrogen atom is very sensitive to these interactions. Here we investigate the origin of these changes by means of theoretical calculations. NEXAFS spectra are simulated for the 1,4-benzenediamine (BDA) molecule in its free, crystalline, and monolayer on Au(111) forms. We identify the electronic states which are affected by these amino-based interactions. In the case of the molecular layer grown on the gold substrate, we show how the results of the calculations can be used to identify intermolecular interactions influencing adsorption geometries in molecular monolayers

    Chemistry of the Methylamine Termination at a Gold Surface: From Autorecognition to Condensation

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    13The self-assembly of the naphthylmethylamine molecules (NMA) on the Au(111) surface is investigated by a combined experimental and theoretical approach. Three well-defined phases are observed upon different thermal treatments at the monolayer stage. The role played by the methylamine termination is evidenced in both the molecule–molecule and molecule–substrate interactions. The autorecognition process of the amino groups is identified as the driving factor for the formation of a complex hydrogen bonding scheme in small molecular clusters, possibly acting also as a precursor of a denitrogenation condensation process induced by thermal annealing.reservedmixedDri, Carlo; Fronzoni, Giovanna; Balducci, Gabriele; Furlan, Sara; Stener, Mauro; Feng, Zhijing; Comelli, Giovanni; Castellarin-Cudia, Carla; Cvetko, Dean; Kladnik, Gregor; Verdini, Alberto; Floreano, Luca; Cossaro, AlbanoDri, Carlo; Fronzoni, Giovanna; Balducci, Gabriele; Furlan, Sara; Stener, Mauro; Feng, Zhijing; Comelli, Giovanni; Castellarin Cudia, Carla; Cvetko, Dean; Kladnik, Gregor; Verdini, Alberto; Floreano, Luca; Cossaro, Alban
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