75345-82-3Relevant academic research and scientific papers
Kinetics and mechanism of iodination of para-substituted benzylbis(dimethylglyoximato)(pyridine)cobalt(III). High reactivity of the base-off form
Okamoto, Tadashi,Goto, Masafumi,Oka, Shinzaburo
, p. 899 - 904 (1981)
A kinetic study of the iodination of p-XC6H4CH2Co(DH)2(py) (X = methoxy, methyl, H, chloro, nitro; DH = monoanion of dimethylglyoxime; py = pyridine) revealed the rate-determining dissociation of pyridine and subsequent rapid reaction of the base-free form with iodine. The high reactivity of the base-free form is discussed in relation to inner-sphere electron transfer. The rates of dissociation of pyridine showed a Hammett-like linear free-energy relationship with a ρ+ of -1.48.
Free-radical pathways to alkyl complexes of a nickel tetraaza macrocycle
Ram,Bakac, Andreja,Espenson, James H.
, p. 3267 - 3272 (2008/10/08)
The cationic nickel(I) macrocycle (1R,4S,8R,11S)-(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane)nickel(I) , abbreviated R,S,R,S-[Ni(tmc)]+, reacts in aqueous, alkaline solutions on the stopped-flow time scale with alkyl halides to form a new series of organonickel complexes. Kinetic data were obtained for a large number of alkyl halides. The trends in the rate constants are benzyl > allyl > secondary > primary > methyl > cyclopropyl, and RI > RBr > RCl. These trends suggest that carbon-centered free radicals R? are produced by a bimolecular reaction between Ni(tmc)+ and RX and are then captured by a second Ni(tmc)+. Further evidence for free-radical involvement comes from cyclization of the radical produced from 6-bromo-1-hexene, from the yields of products in those instances where dimerization of the free radical competes with its capture by Ni(tmc)+, and from the nonreactivity of alkyl tosylates. The organonickel complexes slowly hydrolyze in unimolecular processes to yield hydrocarbon and the nickel(II) complex R,S,R,S-[Ni(tmc)]2+. The organonickel complexes do not undergo unimolecular homolysis but react with Co(II) macrocycles with a 1:2 stoichiometry to form cobalt-carbon bonds. This reaction most likely occurs not by homolytic displacement but by electron transfer followed by radical capture.
