Water-soluble organometallic compounds. 3. Kinetic investigations of dissociative phosphine substitution processes involving water-soluble group 6 metal derivatives in miscible aqueous/organic media
- Texas A M Univ., College Station (United States)
Mechanistic aspects of ligand substitution reactions of group 6 metal carbonyl derivatives containing the trisulfonated phosphine P(m-C[sub 6]H[sub 4]SO[sub 3]Na)[sub 3] (hereafter referred to as TPPTS) in pure water and water/THF media have been investigated by examination of the reactions of these derivatives with carbon monoxide as an incoming ligand. The reactions, which were carried out under 500 psi of CO in the temperature range 110-160[degrees]C, were monitored in situ by infrared spectroscopy employing a cylindrical internal reflectance reactor. Kinetic measurements show the reactions are first-order in metal complex concentration and independent of CO pressure at high CO pressures, and the rates are retarded by added TPPTS. The activation parameters for TPPTS dissociation from M(CO)[sub 5]TPPTS derivatives (M = Mo, W), e.g., in 1:1 THF/H[sub 2]O, [Delta]H[double dagger] = 28.8 [plus minus] 1.4 kcal/mol and [Delta]S[double dagger] = [minus]4.2 [plus minus] 3.5 eu and [Delta]H[double dagger] = 31.8 [plus minus] 1.5 kcal/mol and [Delta]S[double dagger] = [minus]0.73 [plus minus] 3.6 eu, respectively were shown to be quite similar to those determined for the analogous processes involving the nonsulfonated PPh[sub 3] ligand in the same solvent systems. In addition only small solvent effects were noted in going from aqueous to organic solvents for these dissociative processes. For the cis-Mo(CO)[sub 4][TPPTS][sub 2] derivative, in which the sodium ions are encapsulated by a cryptand, kryptofix-221, a steric acceleration of TPPTS dissociation is noted relative to its PPh[sub 3] analog. 27 refs., 5 figs., 6 tabs.
- OSTI ID:
- 6924286
- Journal Information:
- Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 32:1; ISSN 0020-1669; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
AQUEOUS SOLUTIONS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COHERENT SCATTERING
COMPLEXES
DATA
DIFFRACTION
DISPERSIONS
EXPERIMENTAL DATA
INFORMATION
KINETICS
LIGANDS
MIXTURES
MOLYBDENUM COMPLEXES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOMETALLIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOSPHINES
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
SCATTERING
SOLUTIONS
SPECTROSCOPY
SULFONATES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES
X-RAY DIFFRACTION