Photolysis of Tp[prime]Rh(CN-neopentyl)([eta][sup 2]-PhN[double bond]C[double bond]N-neopentyl) in alkanes and arenes: Kinetic and thermodynamic selectivity of [Tp[prime]Rh(CN-neopentyl)] for various types of C-H bonds

Journal Article · Tue Jan 26 23:00:00 EST 1993 · Journal of the American Chemical Society; (United States)

DOI:https://doi.org/10.1021/ja00055a027· OSTI ID:6539260

Jones, W D; Hessell, E T ^[1]

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1. Univ. of Rochester, NY (United States)

Irradiation of the carbodiimide complex [HB(3,5-dimethylpyrazolyl)[sub 3]]Rh(CNR)(PhN[double bond]C[double bond]NR) (R = neopentyl) in benzene, toluene, mesitylene, cyclopentane, cyclohexane, propane, or pentane solvent leads to both the clean elimination of the carbodiimide ligand and the formation of the C-H oxidative addition product [HB(3,5-dimethylpyrazolyl)[sub 3]]Rh(CNR)(R[prime])H. These products have been isolated as their chloride derivatives. Methane can be activated by exchange with the cyclohexyl derivative. The n-pentyl derivative [HB(3,5-dimethylpyrazolyl)[sub 3]]Rh(CNR)(n-pentyl)Cl crystallizes in monoclinic space group P2[sub 1]/c with a = 8.8864 (28) [Angstrom], b = 11.8016 (30) [Angstrom], c = 31.4597 (14) [Angstrom], [beta] = 90.727 (22)[degrees], Z = 4, and V = 3098 (2) [Angstrom][sup 3]. Competitive studies show that both benzylic and aromatic C-H bonds react under conditions of kinetic control but that the aromatic activation products are thermodynamically preferred. Activation of primary alkane C-H bonds is preferred over secondary activation. This complex is found to be more selective than either [Cp[sup *]Rh(PMe[sub 3])] or [Cp[sup *]Ir(PMe[sub 3])]. The rates of reductive elimination of n-pentane, cyclopentane, cyclohexane, mesitylene, methane, and benzene have been measured and are used to establish relative Rh-R bond strengths for these ligands. 25 refs., 5 figs., 8 tabs.

• DOE Contract Number: FG02-86ER13569
• OSTI ID: 6539260
• Journal Information: Journal of the American Chemical Society; (United States), Journal Name: Journal of the American Chemical Society; (United States) Vol. 115:2; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
ALKYLATED AROMATICS
AROMATICS
BENZENE
CHEMICAL ACTIVATION
CHEMICAL BONDS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPLEXES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CYCLOALKANES
CYCLOHEXANE
DECOMPOSITION
DIFFRACTION
HYDROCARBONS
KINETICS
LATTICE PARAMETERS
MAGNETIC RESONANCE
MESITYLENE
METHANE
MONOCLINIC LATTICES
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
PENTANE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PROPANE
REACTION KINETICS
RESONANCE
RHODIUM COMPLEXES
SCATTERING
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TOLUENE
TRANSITION ELEMENT COMPLEXES
X-RAY DIFFRACTION