Formation and reactivity of metal-ligand bonds: platinum(I) dimers and cobalt and chromium alkyls

Technical Report · Fri Mar 01 04:00:00 EST 1985

OSTI ID:5920639

Blau, R J

(Pt/sub 2/(..mu..-dppM)/sub 2/Cl(PPh/sub 3/))/sup +/ is formed from a rate-limiting bimolecular reaction of PPh/sub 3/ with (Pt/sub 2/(..mu..-dppM)/sub 2/Cl/sub 2/) in CH/sub 2/Cl/sub 2/. Alternatively, it and its bromo and chloro derivatives can be formed from the reaction of halides with (Pt/sub 2/(..mu..-dppM)/sub 2/(PPh/sub 3/)/sub 2/)/sup 2 +/ by (a) rate-limiting PPh/sub 3/ dissociation, or (b) rate-limiting Pt/sub 2/(..mu..-dppM) ring opening at a Pt-P bond. Formation of product by (b) occurs after the formation of two observable intermediates, one of which, (Pt/sub 2/(eta/sup 2/-dppM)(..mu..-dppM)-X(PPh/sub 3/))/sup +/, is readily characterized by /sup 31/P(/sup 1/H) NMR spectroscopy. Atropisomers due to hindered rotation around the Pt-PPh/sub 3/ bond of (Pt/sub 2/(..mu..-dppM)/sub 2/Cl(PPh/sub 3/))/sup +/ are caused by phenyl-phenyl repulsions and can be distinguished by /sup 31/P(/sup 1/H) NMR spectroscopy. Such repulsions also retard the rate of positional interchange of axial and equatorial substituents on its Pt/sub 2/(..mu..-dppM)/sub 2/ ring as observed by /sup 1/H NMR spectroscopy. Several correlations between /sup 195/Pt-/sup 31/P coupling constants and Pt-P and Pt-Pt bond lengths were observed. The synthesis, characterization, and reactivity of ((Pt/sub 2/(..mu..-dppM)/sub 2/Cl)/sub 2/(di-eta/sup 2/-P/sub 4/))/sup 2 +/ is reported. This complex is a dimer of platinum dimers bridged by tetra-phosphorus. One platinum of each dimer is bound to two phosphorus atoms of P/sub 4/. The formation and reactivity of the metal-carbon bonds in benzylcobalamin and chromium alkyls, ((H/sub 2/O)/sub 5/CrR/sup 2 +/; R = CH/sub 2/Ph, CH(CH/sub 3/)OC/sub 2/H/sub 5/, CH/sub 2/OCH/sub 3/), were also investigated. 91 references, 55 figures, 32 tables.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5920639
• Report Number(s): IS-T-1165; ON: DE85009224
• 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)
ABSORPTION SPECTROSCOPY
ACTIVATION ENERGY
ARYL RADICALS
BENZYL RADICALS
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM
COBALT
COMPLEXES
COUPLING
COUPLING CONSTANTS
DATA
DIMERS
ELECTRON TRANSFER
ELEMENTS
ENERGY
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
HYDROXYL RADICALS
INFORMATION
INTERMEDIATE COUPLING
J-J COUPLING
KINETICS
LIGANDS
LOW TEMPERATURE
MAGNETIC RESONANCE
MEDIUM TEMPERATURE
METALS
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
PLATINUM CHLORIDES
PLATINUM COMPLEXES
PLATINUM COMPOUNDS
RADICALS
REACTION KINETICS
RESONANCE
SPECTROSCOPY
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS