Olefin Complexes of the Transition Metals

Silver-Facilitated Olefin/Paraffin Separation in a Liquid Membrane Contactor System

“…The interaction of silver(I) cations with olefins has been studied extensively (Bennett, 1962;Hartley, 1973;Quinn et al, 1969;Winstein et al, 1938). Since the equilibrium constant is defined in terms of activities rather than concentrations, and activities usually depend markedly on concentrations, the equilibrium constants reported in the literature are usually determined at very dilute aqueous solutions of AgNOs where the activity coefficients approach unity.…”

Towards understanding monomer coordination in atom transfer radical polymerization: synthesis of [CuI(PMDETA)(π-M)][BPh4] (M = methyl acrylate, styrene, 1-octene, and methyl methacrylate) and structural studies by FT-IR and 1H NMR spectroscopy and X-ray crystallography

“…Controlling the reaction still remains a challenge, and detailed mechanistic studies concerning olefin coordination to transition metals will be necessary for any further advances made in this field. Olefin-transition metal complexes have been the subject of numerous reviews [5][6][7][8][9][10]. According to the widely accepted model proposed by Dewar [11] and by Chatt and Duncanson [12], the metal-olefin bond has both r and p components; which component dominates depends on the direction of transfer of electron density (from the metal to the olefin p * -orbital, or from the olefin p-orbital to the vacant r-type metal orbital).…”

Ethylene Oxide and Propylene Sulfide Complexes of Silver(I): Synthesis and Characterization of [HB(3,5-(CF3)2Pz)3]Ag(OC2H4) and [HB(3,5-(CF3)2Pz)3]Ag(SC3H6)

“…The silver-catalyzed partial oxidation of ethylene to ethylene oxide is one of the most important and thoroughly investigated industrial processes. − Silver−ethylene and silver−ethylene oxide species are two possible intermediates formed on the silver catalyst surface during the reaction. Remarkably, despite the interest, very little is known about structures and properties of silver coordination complexes containing either ethylene or ethylene oxide ligands. − Recently, we reported on the synthesis of one of these complexes, the silver−ethylene adduct [HB(3,5-(CF 3 ) 2 Pz) 3 ]Ag(η 2 -C 2 H 4 ), using a highly fluorinated tris(pyrazolyl)borate ligand (where HB(3,5-(CF 3 ) 2 Pz) 3 = hydrotris(3,5-bis(trifluoromethyl)pyrazolyl)borate). − Unlike the typical silver(I)−ethylene complexes, [HB(3,5-(CF 3 ) 2 Pz) 3 ]Ag(η 2 -C 2 H 4 ) does not lose ethylene under reduced pressure. − Therefore, its properties can be investigated conveniently using a variety of techniques, including X-ray crystallography. In this paper, we describe the successful utility of the [HB(3,5-(CF 3 ) 2 Pz) 3 ] - ligand in the isolation of the ethylene oxide adduct [HB(3,5-(CF 3 ) 2 Pz) 3 ]Ag(OC 2 H 4 ).…”