New series of chelated organochromium(III) complexes. [1,4,8,12-Tetraazacyclopentaedecane]
A kinetic and mechanistic study of the preparation of a new family of chelated organochromium(III) complexes was completed. These species were formed from organic halides and (1,4,8,12 tetraazacyclopentadecane) chromium(II) by a mechanism which involves initial halogen atom abstraction followed by subsequent radical capture by another Cr(II) complex. The rates of reaction follow the pattern expected for a S/sub H/2 process, 3/sup 0/ > 2/sup 0/ > 1/sup 0/ and I > Br > Cl. These organochromium(III) chelate complexes have the trans configuration. Electrophilic cleavage reactions by mercuric and methylmercuric ions were studied. These reactions proceed by a S/sub E/2 (open) mechanism with the reaction rates being approx. 100 times slower for the chelated species. The activation parameters were determined for five reactions. The crystal structure of (trans-chloroaquo(1,4,8,12-tetraazacyclopentadecane)chromium(III))diiodide-dihydrate is also reported. The macrocycle assumes the lowest energy conformation as predicted by strain energy calculations.
- Research Organization:
- Ames Lab., IA (USA)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 6378118
- Report Number(s):
- IS-T-848
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMINES
CHELATES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHROMIUM COMPLEXES
COMPLEXES
CRYSTAL STRUCTURE
DATA
DATA FORMS
EXPERIMENTAL DATA
INFORMATION
ISOLATED VALUES
KINETICS
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
REACTION KINETICS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
400201* -- Chemical & Physicochemical Properties
AMINES
CHELATES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHROMIUM COMPLEXES
COMPLEXES
CRYSTAL STRUCTURE
DATA
DATA FORMS
EXPERIMENTAL DATA
INFORMATION
ISOLATED VALUES
KINETICS
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
REACTION KINETICS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES