Reactions of disubstituted alkanes with a nickel(I) macrocycle

Journal Article · Wed Nov 16 04:00:00 EST 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00296a028· OSTI ID:5975657

Ram, M S; Bakac, A; Espenson, J H

The reactions of disubstituted alkanes, X(CH/sub 2/)/sub n/Y (X, Y = Cl, Br, I, OH, OTs), with the cationic macrocyclic ion (1R,4S,8R,11S)-(1,4,8,11S)-(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane)nickel(I), abbreviated Ni(tmc)/sup +/, are characterized by kinetic accelerations compared to the rates for the monohalides, most noticeably for the smaller molecules, n = 2,3. No transient organonickel species is detected for any vicinal disubstituted alkane, and the alkene is formed quantitatively. This is attributed to a reductive elimination reaction between Ni(tmc)/sup +/ and the radical /center dot/CH/sub 2/CH/sub 2/OH, known to result from the very rapid unimolecular solvolysis of the initially formed /center dot/CH/sub 2/CH/sub 2/Y. Although Br(CH/sub 2/)/sub 3/OH yields 1-propanol from the hydrolysis of the observed species (tmc)Ni(CH/sub 2/)/sub 3/OH/sup +/, 1,3-disubstituted propanes (X, Y = Br, Cl, OTs) form cyclopropane exclusively. A rapid unimolecular reaction of (tmc)Ni(CH/sub 2/)/sub 3/Y/sup +/ appears responsible. The 1,4-disubstituted alkanes yield (tmc)Ni(CH/sub 2/)/sub 4/Y/sup +/ deficient Ni(tmc)/sup +/, but ethylene is formed rapidly and quantitatively in the presence of even a catalytic concentration of Ni(tmc)/sup +/ (with Y = Br, I and to some extent Y = Cl). Similarly, (tmc)NiCH(CH/sub 3/)(CH/sub 2/)/sub 3/Y/sup +/ forms a 1:1 mixture of ethylene and propene (Y = Br, I) when Ni(tmc)/sup +/ is present and otherwise hydrolyzes to 1-Y pentane. Alkene formation from 1,4-disubstituted alkanes is attributed to the reaction of (tmc)Ni(CH/sub 2/)/sub 4/Y/sup +/ with Ni(tmc)/sup +/, producing a species (tmc)Ni(CH/sub 2/)/sub 4//sup /center dot/+/ that yields ethylene and regenerates Ni(tmc)/sup +/. 36 refs., 3 tabs.

• Research Organization: Iowa State Univ., Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5975657
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:23; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
CHEMICAL REACTIONS
DATA
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
NICKEL COMPOUNDS
NUMERICAL DATA
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
TRANSITION ELEMENT COMPOUNDS