Dynamics of monoolefin-metal ion complexes in the gas phase: determination of the number of labile hydrogens by reaction with C/sub 2/D/sub 4/

Journal Article · Wed Jan 09 04:00:00 EST 1985 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00287a014· OSTI ID:5781653

Jacobson, D B; Freiser, B S

H/D exchange reactions of organometallic ions with D/sub 2/ in the gas phase have proven valuable in determining the number of labile hydrogens in the complex. Unfortunately, many complexes are not observed to exchange with D/sub 2/. In this paper we demonstrate that C/sub 2/D/sub 4/ can extend the variety of complexes which may be studied. The propene complexes of Fe/sup +/, Co/sup +/, and Ni/sup +/ which are unreactive with D/sub 2/ undergo 5 H/D exchanges with C/sub 2/D/sub 4/. These results are rationalized by invoking an equilibrium between the propene and hydrido-..pi..-allyl species promoted by the activation afforded by ethene-d/sub 4/ coordination. The Rh(propene)/sup +/ complex is observed to exchange all 6 hydrogens suggesting an additional mechanism involving a vinylic C-H bond insertion. In addition, this Rh(propene)/sup +/ species undergoes multiple exchangers per C/sub 2/D/sub 4/ encounter in contrast to the M(propene)/sup +/ species of Fe/sup +/, Co/sup +/, and Ni/sup +/ which undergo only a single exchange per C/sub 2/D/sub 4/ encounter. The rate of the above exchanges falls into the order Rh/sup +/ > Co/sup +/ > Fe/sup +/ > Ni/sup +/. Rh(1,3-pentadiene)/sup +/ undergoes 5 rapid exchanges with C/sub 2/D/sub 4/ while the corresponding iron and cobalt complexes yield 5 slow exchanges with no exchange observed for the nickel complex. No multiple exchanges occur for these pentadiene ions. The isomeric Rh(2-methylbutadiene)/sup +/ species undergoes 5 slow exchanges with none observed for the iron, cobalt, and nickel species. M-c-C/sub 5/H/sub 6//sup +/ (M = Fe, Co, Ni) undergo 6 rapid exchanges with multiple exchanges predominating. The Rh-c-C/sub 5/H/sub 6//sup +/ species only undergoes one rapid exchange. Both Rh-c-C/sub 7/H/sub 8//sup +/ and Co-c-C/sub 7/H/sub 8//sup +/ generated from cycloheptatriene yield one slow exchange with C/sub 2/D/sub 4/ with none observed for Fe-c-C/sub 7/H/sub 8//sup +/ and Ni-c-C/sub 7/H/sub 8//sup +/. 69 references, 8 figures.

• Research Organization: Purdue Univ., West Layfayette, IN
• DOE Contract Number: AC02-80ER10689
• OSTI ID: 5781653
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 107:1; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKENES
BUTENES
CATIONS
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COBALT COMPLEXES
COMPLEXES
CYCLOALKENES
CYCLOPENTADIENE
DATA
DEUTERIUM
DEUTERIUM COMPOUNDS
DIENES
EQUILIBRIUM
ETHYLENE
EXPERIMENTAL DATA
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
INFORMATION
IONS
IRON COMPLEXES
ISOTOPE APPLICATIONS
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
MASS SPECTROSCOPY
NICKEL COMPLEXES
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
POLYENES
PROPYLENE
REACTION INTERMEDIATES
REACTION KINETICS
RHODIUM COMPLEXES
SPECTROSCOPY
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
TRACER TECHNIQUES
TRANSITION ELEMENT COMPLEXES