Nitrogen-15 NMR studies of tetrazole complexes of pentaamminecobalt(III). Implications concerning the transition state for linkage isomerization

S. Hubinger, J. H. Hall, W. L. Purcell

Research output: Contribution to journalArticle

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Abstract

Synthesis of the N1-bonded (5-methyltetrazolato)pentaamminecobalt(III) complex utilizing sodium azide enriched in 15N at the terminal nitrogen has produced a complex enriched specifically at the N2 and N4 ring positions. This has permitted the assignment of all four nitrogen signals in the natural-abundance 15N NMR spectrum of the complex. A similar natural-abundance NMR spectrum for a novel chelated amidine complex which is also N1 bonded is reported along with its synthesis and purification. Following the 15N NMR of the linkage isomerization of the enriched complex in solution to the N2-bonded form has also permitted an η5 and certain η3 transition-state structures to be eliminated from consideration for the isomerization process. The data suggest an η2 transition state is utilized. A subsequent N2-to-N3 isomerization of the N2-bonded complex has also been discovered from the 15N NMR study. The enrichment study also indicates that previous assignments of ring nitrogen signals N1 and N4 in similar N2-bonded tetrazolato complexes of cobalt(III) may be in error.

Original languageEnglish
Pages (from-to)2394-2398
Number of pages5
JournalInorganic Chemistry
Volume32
Issue number11
StatePublished - Dec 1 1993

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nitrogen 15
tetrazoles
Isomerization
linkages
isomerization
Nitrogen
Nuclear magnetic resonance
nuclear magnetic resonance
nitrogen
Amidines
sodium azides
Sodium Azide
rings
synthesis
Cobalt
purification
Purification
cobalt
1H-tetrazole

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Nitrogen-15 NMR studies of tetrazole complexes of pentaamminecobalt(III). Implications concerning the transition state for linkage isomerization. / Hubinger, S.; Hall, J. H.; Purcell, W. L.

In: Inorganic Chemistry, Vol. 32, No. 11, 01.12.1993, p. 2394-2398.

Research output: Contribution to journalArticle

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