Hypochlorite oxidation of morpholine-borane

Journal Article · Thu Apr 01 00:00:00 EST 1982 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00134a069· OSTI ID:5318305

Wilson, I; Kelly, H

Morpholine-borane reacts with sodium hypochlorite in a 1:4 mole ratio wherein three OCl/sup -/ species are utilized for hydride oxidation and a fourth is consumed in the chlorination of morpholine. The determination of kinetic parameters, based upon the stopped-flow spectrophotometric measurement of the rate of disappearance of OCl/sup -/ at 290 nm (pH9-11), is complicated by these consecutive competitive reactions of hypochlorite. At a given pH, the second-order rate constant for the reaction of OCl/sup -/ with morpholine is about 10/sup 3/ times greater than that for attack of hypochlorite on amine-borane; thus, a reliable determination of the latter constant was based upon ''initial rate'' studies under pseudo-first-order conditions involving a large stoichiometric excess of morpholine-borane. The rate of reaction of hypochlorite with amine-borane is also first order in hydrogen ion and is subject to a normal substrate isotope effect with O(CH/sub 2/)/sub 4/NH.BH/sub 3/ reacting about 1.6 times more rapidly than O(CH/sub 2/)/sub 4/NH.BD/sub 3/. At a given lyonium ion concentration, the reaction is enhanced by a factor of about 3.5 in D/sub 2/O. It is proposed that the rate-limiting step involves oxidative attack of hypochlorous acid at a boron-hydrogen bond in the amine-borane and that subsequent oxidation of the two remaining hydridic hydrogen atoms is rapid relative to the chlorination of morpholine. The inverse solvent isotope effect is attributed to a higher concentration of DOCl in D/sub 2/O relative to that of HOCl in normal water at a given pD (pH), but is likely that this influence is partially offset by a normal secondary isotope effect associated with attack of HOCl (DOCl) at the B-H bond.

• Research Organization: Texas Christian Univ., Fort Worth
• OSTI ID: 5318305
• Journal Information: Inorg. Chem.; (United States), Vol. 21:4
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BORANES
OXIDATION
DEUTERIUM
ISOTOPE EFFECTS
MORPHOLINES
CHLORINATION
AQUEOUS SOLUTIONS
CHEMICAL ACTIVATION
CHEMICAL REACTION KINETICS
CONCENTRATION RATIO
DIPOLES
EXPERIMENTAL DATA
PH VALUE
REDUCING AGENTS
SPECTRA
STEREOCHEMISTRY
STOICHIOMETRY
AMINES
BORON COMPOUNDS
CHEMICAL REACTIONS
DATA
DISPERSIONS
ETHERS
HALOGENATION
HETEROCYCLIC COMPOUNDS
HYDROGEN ISOTOPES
INFORMATION
ISOTOPES
KINETICS
LIGHT NUCLEI
MIXTURES
MULTIPOLES
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
REACTION KINETICS
SOLUTIONS
STABLE ISOTOPES
400302* - Organic Chemistry- Isotope Effects- (-1987)
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)