J . Phys. Chem. 1992, 96, 1144-1 146
1144
EPR Spectrum of AgPF,+ M. Histed, J. A. Howard,* R. Jones, M. Tomietto, Steacie Institute for Molecular Sciences, National Research Council, Ottawa, Ontario, Canada Kl A OR9
and H. A. Joly* Department of Chemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Received: August 5, 1991)
The mononuclear monoligand silver(0) complex AgPF, has been prepared by reaction of lo7Agatoms with PF3 at 77 K in an adamantane matrix on a rotating cryostat. This species has the magnetic parameters ulo7(l) = 1685 f 0.3 MHz, a j l ( l ) = 311 f 0.1 MHz, u19(3)= 37.3 f 0.1 MHz, and g = 2.0020 0.0001. It is a Ag-centered radical with a 2Al ground state in the point group C,, formed by interaction of PF3with Ag rather than a phosphorus-centered radical formed by addition of Ag to PF3.
*
Introduction Matrix isolation spectroscopy (EPR, IR, and UV-visible) has shown that Ag atoms react with a variety of organic and inorganic substances (C2H2,lJ C2Hq,1,3-7CH$HCH2,'.' C6H,j,10CH2CCH2,II 02,12J3 C0,1e17 HCN,18J9and SOzo) at cryogenic temperatures to give mononuclear Ag(0) mono-, di-, and triligand complexes. Most of these complexes have dative bonds between the ligands and the metal center that involve u donation of electron density from ligand orbitals into empty metal orbitals and T donation of electron density from metal orbitals into empty antibonding ligand orbitals. There are, however, several examples of the formation of endsn a-bonded Ag complexes; e.g., Ag adds to C2H2to give the vinyl AgCHCH','V2 to CH2CCH2to give CH2C(Ag)CH2,11and to HCN to give the iminyl AgC(H)N'.I8 PF, has both udonor and r-acceptor properties similar to those of C021.22and might also be expected to give mono-, di-, and triligand complexes by reaction with atomic Ag. Alternatively, the Ag atom could add to PF, to give an organometallic phosph~ranyl.~,In this paper we report the formation of the first mononuclear silver-PF3 complex, AgPF,, produced by reaction of Ag atoms with PF3 in a solid adamantane matrix at 77 K on a rotating cryostat. Experimental Section The rotating cryostat technique has been thoroughly described e l ~ e w h e r e . ' ~PF, * ~ ~was prepared by reaction of NaF with PCl, in CH3CN. It was deposited onto a surface of adamantane (Aldrich) at 77 K and bombarded with lo7Agatoms prepared by resistively heating Io7Agmetal (Oak Ridge National Laboratory, Oak Ridge, TN). The reactants (Ag:PF3) and matrix were d e posited in the approximate ratios 1:O.S-5:100so that the reaction products were isolated in layers of adamantane. At the end of an experiment the deposit was scraped from the drum into a 3 mm 0.d. suprasil tube still at 77 K and under high vacuum (
