Synthesis and structural characterization of some 1: 1 adducts of silver (I) salts with (hindered) PR3 bases (R= phenyl, o-tolyl, cyclohexyl)

Syntheses, spectroscopy and single crystal X-ray structural characterizations are recorded for a number of adducts AgX: PR3 (1:1)(n) obtained from the reaction of silver(I) salts with sterically hindered tertiary phosphine bases, extending previous studies. With tris(o-tolyl)phosphine, P(o-tolyl)(3), binuclear adducts AgX: P(o-tolyl)(3) (1:1)(2) are defined, in arrays with eight-membered central rings [(o-tolyl)(3)PAg(mu-tfa)(2)AgP(o-tolyl)(3)] (1) (tfa = trifluoroacetate, O.CO.CF3) where two independent atoms of the anion bridge to the two silver atoms, and four-membered central rings where one atom bridges (Cl, NCO, acetate (= 'ac', O.CO.CH3)) (complexes 2-4); the perchlorate (5) is intermediate, one perchlorate bridging via one oxygen and the other by two. The nitrate is mononuclear, [(o-tolyl)(3)PAgO2NO], (6) with chelating nitrate. The bromide takes a tetranuclear 'cubane' form (7). With the cyanide, an interesting 2:1 AgCN: (o-tolyl)(3)P adduct (8) is defined as a two-dimensional polymer. The archetypical cubane series with triphenylphosphine is extended with a new bromide structure, MeCN solvated [(Ph3P)AgBr](4).0.22MeCN (9), to encompass also the cyanate [(Ph3P)Ag(NCO)](4) (10), isomorphous with the previously defined Cu/As/I chloroform solvate. The 'cubane' form is defined also for a further iodide polymorph AgI: Pcy(3) (1:1)(4) (11).