Pathways for formation of transition metal--carbon bonds in protic media

Conference · Sun Jan 01 04:00:00 EST 1978

DOI:https://doi.org/10.1021/bk-1978-0082.ch014· OSTI ID:6625614

Espenson, J H

The compounds of interest are sigma-bonded organometallic complexes, chiefly of cobalt and chromium. This includes a series of tetradentate macrocyclic complexes of cobalt, RCo(chel)B with B=H/sub 2/O, py, etc. aquochromium complexes, ((H/sub 2/O)/sub 5/Cr-R/sup 2 +/), and chromium complexes containing the macrocyclic ligand (15)ane N/sub 4/. The prototype of the organocobalt structures is that of the vitamin B/sub 12/ derivative methylcobalamin. The most successful and abundant family of model compounds are the bis(dimethylglyoximato) complexes; these are the compounds R-Co(dmgH)/sub 2/B. The consideration of synthetic methods for such sigma organometallics, as well as their reaction chemistry, can be systematized by means of somewhat artificial oxidation state assignments. The organic group R is customarily regarded as a carbanion R:/sup -/. Thus the following specific compounds, considering their ionic charges and that on the other ligands (if any), are all derivatives of M(III): CH/sub 3/CH/sub 2/-Co(dmgH)/sub 2/py, ((H/sub 2/O)/sub 5/Cr-CH/sub 2/CH/sub 3/CH/sub 3/)/sup 2 +/, (CH/sub 3/-Co((14)ane N/sub 4/)H/sub 2/O)/sup 2 +/, and (CH/sub 3/-Co(dpnH)H/sub 2/O)/sup +/. Preparative methods including methods based on free radicals, nucleophilic pathways via Co, and electrophilic pathways are reviewed. (JRD)

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6625614
• Report Number(s): IS-M-140; CONF-780305-20
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400300* -- Organic Chemistry-- (-1987)
CARBON
CHEMICAL BONDS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COMPLEXES
ELEMENTS
NONMETALS
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
RADICALS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS