Synthesis and properties of ((eta-C/sub 5/H/sub 5/)Re(NO)(PPh/sub 3/)(==CHC/sub 6/H/sub 5/)/sup +/PF/sub 6//sup -/: a benzylidene complex that is formed by a stereospecific. cap alpha. -hydride abstraction,e xists as two geometric isomers, and undergoes stereospecific nucleophilic attack

Journal Article · Wed Sep 08 00:00:00 EDT 1982 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00382a021· OSTI ID:6629562

Kiel, W A ^[1]; Lin, G Y; Constable, A G; McCormick, F B; Strouse, C E; Eisenstein, O; Gladysz, J A

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1. Univ. of California, Los Angeles

Reaction of (eta-C/sub 5/H/sub 5/)Re(NO)(PPh/sub 3/)(CH/sub 2/C/sub 6/H/sub 5/) (1) with Ph/sub 3/C/sup +/PF/sub 6//sup -/ at -78/sup 0/C gives the benzylidene sc-((eta-C/sub 5/H/sub 5/)Re(NO)(PPh/sub 3/)(==CHC/sub 6/H/sub 5/)/sup +/PF/sub 6//sup -/ (2k), which isomerizes upon warming (t/sub 1/2/ = 17 min at 29.5/sup 0/C, ..delta..H/sup + +/ = 20.9 +- 0.4 kcal/mol, ..delta..S/sup + +/ = 3.8 +- 0.2 eu) to a new Re==C geometric isomer, ac-((eta-C/sub 5/H/sub 5/)Re(NO)(PPh/sub 3/)(==CHC/sub 6/H/sub 5/))/sup +/PF/sub 6//sup -/ (2t). The 2t/2k equilibrium mixture is greater than or equal to 99:1, but irradiation between -78 and -20/sup 0/C establishes a (55 +- 3):(45 +- 3) photostationary state. The structures of 2t and 2k are confirmed by x-ray crystallography (t) and extended Hueckel MO calculations. Nucleophiles (Nu) Li(C/sub 2/H/sub 5/)/sub 3/BD, CH/sub 3/Li, CH/sub 3/CH/sub 2/MgBr, C/sub 6/H/sub 5/MgCl, PMe/sub 3/, and CH/sub 3/ONa attack 2t and 2k to give diastereomerically pure adducts (eta-C/sub 5/H/sub 5/)Re(NO)(PPh/sub 3/)(CHNuC/sub 6/H/sub 5/), in which a new chiral center is sterospecifically generated. 7 figures, 6 tables.

• OSTI ID: 6629562
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 104:18; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400500 -- Photochemistry
ABSORPTION SPECTRA
ADDUCTS
AROMATICS
BOND ANGLE
BOND LENGTHS
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPLEXES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DECOMPOSITION
DIFFRACTION
DIMENSIONS
EXPERIMENTAL DATA
INFORMATION
ISOMERIZATION
KINETICS
LENGTH
LIGANDS
LOW TEMPERATURE
MAGNETIC RESONANCE
MATHEMATICAL MODELS
MEDIUM TEMPERATURE
MOLECULAR ORBITAL METHOD
MOLECULAR STRUCTURE
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOMETALLIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
REACTION KINETICS
RESONANCE
RHENIUM COMPLEXES
SCATTERING
SPECTRA
SYNTHESIS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TRANSITION ELEMENT COMPLEXES
TRICLINIC LATTICES
X-RAY DIFFRACTION
YIELDS