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Reactions of the phosphinoacetylenes RR′PCCR″ (R R′ Ph, R″ H, CF3, Ph, Me, t-Bu; R R′ C6F5, R″ Ph, Me; R Ph, R′ Me, R″ Me) with Co2(CO)8 have been studied. Complexes of four types have been characterised: (A)(RR′PC2R″)CO2(CO)6 (R R′ C6F5, R″ Ph, Me; R R′ Ph, R″ t-Bu), (B) (RR′PC2R″)2Co4(CO)10 (R R′ Ph, R″ H, CF3, Ph, Me; R R′ C6F5, R″ Me; R Ph, R′ Me, R″ Me), (C) (RR′PC2R″)2Co2(CO)6 (R R′ Ph, R″ t-Bu), (D) (RR′P(O)C2R″)Co2(CO)6 (R R′ Ph, R″ t-Bu; R R′ C6F5, R Ph). The complexes were characterised by microanalysis, IR, NMR and where possible mass spectra. Substitution reactions of the complexes with tertiary phosphites are described. In complexes of type (A) only the alkyne function is utilised whereas the tetranuclear compounds (B) have structures in which both alkyne and phosphorus moieties are coordinated. Compounds of type (C) are simple disubstituted phosphine complexes of Co2(CO)8 and those of type (D) are μ-alkyne derivatives of acetylenic phosphine oxides. The mechanism of formation of complexes of type (B) is discussed in the light of IR data. 相似文献
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van den Brink HB Blok HP Bobeldijk I Bouwhuis M Dodge GE Harakeh MN Hesselink WH Ireland DG de Jager CW Jans E de Jonge N Kalantar-Nayestanaki N Kasdorp WJ Ketel TJ Konijn J Lapikás L van Leeuwe JJ van der Meer RL Nooren GJ Norum BE Passchier E Pellegrino AR Spaltro CM van der Steenhoven G Steijger JJ Templon JA Theunissen JA van Uden MA de Vries H de Vries R de Witt Huberts PK 《Physical review letters》1995,74(18):3561-3564
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Single crystal electrical resistivity and thermoelectric power (TEP) measurements as a function of temperature are repotted in Rb-TCNQ-II. Results suggest intrinsic conductivity by holes above 360 K with an activation energy of 0.44 eV. Below room temperature conductivity is extrinsic and is due to donors located 0.18 eV below the conduction band. 相似文献
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Harikrishnan Sreekumaran Ashish R. Hota Andrew L. Liu Nelson A. Uhan Shreyas Sundaram 《European Journal of Operational Research》2021,288(2):523-538
In this work, we introduce multi-interdictor games, which model interactions among multiple interdictors with differing objectives operating on a common network. As a starting point, we focus on shortest path multi-interdictor (SPMI) games, where multiple interdictors try to increase the shortest path lengths of their own adversaries attempting to traverse a common network. We first establish results regarding the existence of equilibria for SPMI games under both discrete and continuous interdiction strategies. To compute such an equilibrium, we present a reformulation of the SPMI game, which leads to a generalized Nash equilibrium problem (GNEP) with non-shared constraints. While such a problem is computationally challenging in general, we show that under continuous interdiction actions, an SPMI game can be formulated as a linear complementarity problem and solved by Lemke’s algorithm. In addition, we present decentralized heuristic algorithms based on best response dynamics for games under both continuous and discrete interdiction strategies. Finally, we establish theoretical lower bounds on the worst-case efficiency loss of equilibria in SPMI games, with such loss caused by the lack of coordination among noncooperative interdictors, and use the decentralized algorithms to numerically study the average-case efficiency loss. 相似文献