AbstractInteraction of AgCl with bis(diphenylphosphino)methane (dppm) in THF/MeCN in the presence of K[PF6] or [Et4N]Br afforded typical trinuclear cationic trigonal-bipyramidal complexes [Ag3(μ3-Cl)2(μ-dppm)3][PF6] (1) or [Ag3(μ3-Br)2(μ-dppm)3][AgBr2] (2), respectively. Treatment of AgBr with bis(diphenylphosphino)ethane (dppe) in THF/MeCN in the presence of [Et4N]Br gave a polymeric complex {[Et4N][Ag2(μ-Br)3(μ-dppe)]}n (3) with a dinuclear {Ag2(μ-Br)3} core. The reaction of AgCl with dppe or bis(diphenylphosphino)propane (dppp) in THF/MeCN in the presence of [Et4N]Cl resulted in the isolation of a dinuclear anionic complex [Et4N]2[(AgCl2)2(μ-dppe)] (4) with one μ-dppe bridge or a dinuclear neutral complex [(AgCl)2(μ-dppp)2] (5) with two μ-dppp bridges and a 12-membered ring, respectively. The structures of complexes 1–5 with the bidentate phosphine ligands were determined by single-crystal X-ray diffraction.
The 2-substituted phenylphosphine bidentate hybrid ligands, 2-aminophenyl-, 2-methylamino- phenyl-, 2-hydroxphenyl- and (2-amino-3-methylpheny1)- diphenylphosphine , (1a-d), respectively, and 2-aminophenylmethylphenylphosphine, (le), were synthesized by reduction of their phenylphosphoniurn halides, (2a-e)X (X = Cl or Br), with sodium naphthalenide in tetrahydrofuran at -68�, or electrochemically at a mercury cathode. The phosphonium salts were prepared by reaction of triphenylphosphine with aryl halide and anhydrous nickel halide at 200�. X-Ray diffraction of (2a)2 [NiCl4] showed it to have monoclinic space group P21/n, a 10.657(4), b 20.966(3), c 20.422(6) � , β101.33(2)
and Z4.
The structure was refined by a full-matrix least-squares procedure to a final R 0.050 for 3534 reflections with I
Reaction enthalpies of (COD)Ru(allyl)2 (COD = η4-1,5-cyclooctadiene; allyl = 2-methylpropenyl) with a series of bidentate phosphines (dppm, dppf, dppe, dppb, dppp, depe, dmpe) have been measured by anaerobic solution calorimetry. The relative stability of the resulting complexes is strongly influenced by the electronic donor properties of the bidentate phosphine ligand. Reactions involving ligands that are better σP) donors result in higher enthalpy values and, therefore, more thermodynamically stable complexes. Additionally, the synthesis and characterization of two new ruthenium allyl complexes Ru(allyl)2(dppf) (3) and Ru(allyl)2(depe) (8) and the X-ray crystal structure of 3 are reported.Key words: ruthenium, allyl, solution calorimetry, thermodynamics, X-ray structure.
Experimental and Computational Studies of the Isomerization Reactions of Bidentate Phosphine Ligands in Triosmium Clusters: Kinetics of the Rearrangements from Bridged to Chelated Isomers and X-ray Structures of the Clusters Os3(CO)10(dppbz), 1,1-Os3(CO)10(dppbzF4), HOs3(CO)9[μ-1,2-PhP(C6H4-η1)C6H4PPh2], and HOs3(CO)9[μ-1,2-PhP(C6H4-η1)C6F4PPh2]