Chemistry of the scandium-benzyne ion in the gas phase

Journal Article · Wed Oct 02 04:00:00 EDT 1991 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00020a010· OSTI ID:7073949

Huang, Yongqinq; Hill, Y D; Sodupe, M; Bauschlicher, Jr, C W; Freiser, B S ^[1]

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1. Purdue Univ., West Lafayette, IN (United States) NASA Ames Research Center, Moffet Field, CA (United States)

The reactant ion, ScC[sub 6]H[sub 4][sup +], was prepared from the dehydrogenation of benzene by Sc[sup +]. ScC[sub 6]H[sub 4][sup +] undergoes an unusual hydrogenation reaction with H[sub 2] and D[sub 2], as well as H/D exchange with the latter. Its reactions with a number of oxygen-containing species, XO, give ScO[sup +]. The ability to form stable C[sub 6]H[sub 4]X neutral products from benzyne is a key factor in making this reaction exothermic. With the exception of methane, ScC[sub 6]H[sub 4] reacts with all of the alkanes and alkenes studied to form a wide variety of product ions. Sc[sup +]-styrene is formed from the reaction with ethane and propane. Sc[sup +]-indane is also formed from the reaction with propane. The product ion ScC[sub 8]H[sub 10][sup +] from n-butane is Sc[sup +]-ethylbenzene. A prominent ion, ScC[sub 9]H[sub 7][sup +], is formed from butadiene. Its frequent occurrence, unusual formulation, and resistance to fragmentation all indicate a high stability, with its structure most likely being that of the indenylscandium cation. D[sup 0](Sc[sup +]-benzyne) = 88 [plus minus] 5kcal/mol was determined indirectly from the photodissociation threshold for loss of H[sub 2] from Sc[sup +]-benzene and from the observation that Sc[sup +] exothermically dehydrogenates benzene to form Sc[sup +]-benzyne. Theoretical study indicates that the gas-phase structure is analogous to that of solid-phase mononuclear transition-metal-benzyne complexes observed crystallographically in which the metal center is coplanar with the benzyne ring and inserted symmetrically into the C-C triple bond forming a benzometallacyclopropene. The theoretical bond energy for the planar singlet D[sup 0](Sc[sup +]-C[sub 6]H[sub 4]) = 94 kcal/mol is in good agreement with experiment.

• DOE Contract Number: FG02-87ER13766
• OSTI ID: 7073949
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 30:20; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
ALKENES
AROMATICS
BINDING ENERGY
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
DATA
DEUTERIUM
ELEMENTS
ENERGY
EXPERIMENTAL DATA
FLUIDS
GASES
HYDROCARBONS
HYDROGEN
HYDROGEN ISOTOPES
INFORMATION
IONS
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
NONMETALS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
SCANDIUM COMPOUNDS
STABLE ISOTOPES
THEORETICAL DATA
TRANSITION ELEMENT COMPOUNDS