Reactivity of a 17e organometallic radical in aqueous solution

Journal Article · Sun May 01 04:00:00 EDT 1994 · Organometallics; (United States)

DOI:https://doi.org/10.1021/om00017a053· OSTI ID:7069630

Zhu, Z; Espenson, J H ^[1]

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1. Iowa State Univ., Ames, IA (United States)

Laser flash photolysis of [(C[sub 5]H[sub 4]CO[sub 2])W(CO)[sub 3]][sub 2] in aqueous solution at 460-532 nm induces homolysis of the metal-metal bond with formation of the 17e radical (C[sub 5]H[sub 4]CO[sub 2[minus]])W(CO)[sub 3]. The rate constant for its dimerization is 3.0 x 10[sup 9] L mol[sup [minus]1] s[sup [minus]1] at 23[degree]C. The radical reacts with haloacetate ions, pseudohalo- and halometal complexes by atom transfer. The reactivity trend is normal (RI > RBr > RCl). The reaction between this radical with t-BuOOH in water occurs similarly with a rate constant of 1.37 x 10[sup 6] L mol[sup [minus]1] s[sup [minus]1]. For electron-transfer reactions, the radical acts as both reductant and oxidant. It oxidizes tetramethylphenylenediamine to TMPD[sup [sm bullet]+] in aqueous solution with a rate constant of 1.49 x 10[sup 7] mol[sup [minus]1] s[sup [minus]1]. The radical reduces MV[sup 2+] and Fe(CN)[sub 6][sup 3[minus]] to MV[sup [sm bullet]+] and Fe(CN)[sub 6][sup 4[minus]] with rate constants of 2.0 x 10[sup 6] and 6.06 x 10[sup 7] L mol[sup [minus]1] s[sup [minus]1], respectively. The phosphine Ph[sub 2]PPhSO[sub 3]Na accelerates the reaction of the radical with MV[sup 2+] very mildly. This may bear on the question of whether the tungsten-phosphine adduct is a species with 19 valence electrons, a slipped cyclopentadienyl ring, or a phosphoranyl radical. 32 refs., 2 figs., 4 tabs.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 7069630
• Journal Information: Organometallics; (United States), Journal Name: Organometallics; (United States) Vol. 13:5; ISSN ORGND7; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
AMINES
AQUEOUS SOLUTIONS
AROMATICS
BROMINE COMPOUNDS
CHEMICAL REACTIONS
CHLORINE COMPOUNDS
COMPILED DATA
COMPLEXES
DATA
DECOMPOSITION
DIMERIZATION
DISPERSIONS
HALOGEN COMPOUNDS
INFORMATION
IODINE COMPOUNDS
IRON COMPLEXES
KINETICS
LASERS
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
OXYGEN COMPOUNDS
PEROXIDES
PHOSPHINES
PHOSPHORUS COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
POLYMERIZATION
RADICALS
REACTION KINETICS
REDOX REACTIONS
SOLUTIONS
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES