Cooperative effect of NH bond orientation and triamine six-membered chelate ring rigidity in stereospecific formation of exo-((1,6-diamine-3-azahexane)-(S)-aspartato)cobalt(III) isomers

Autor:	František Jursík, Jana Ondráčková
Rok vydání:	1988
Předmět:	chemistry.chemical_classification chemistry.chemical_compound Stereospecificity Chemistry Stereochemistry Diamine chemistry.chemical_element Chelation General Chemistry Cobalt Inorganic compound
Zdroj:	Collection of Czechoslovak Chemical Communications. 53:2654-2663
ISSN:	1212-6950 0010-0765
DOI:	10.1135/cccc19882654
Popis:	Of the six isomers possible, only exo-sym-fac(S), exo-unsym1-fac(S) and exo-Δ-unsym2-fac(R)-[Co(1,6-dah)(S)-Asp]+ (1,6-dah = 1,6-diamine-3-azahexane) isomers were prepared and characterized by electronic absorption and circular dichroism spectra. Isomers formation is stereospecific due to the linear triamine NH bond orientation which causes that of the three sites in mer(R or S)-[Co(1,6-dah)(H2O)3]3+ intermediates, only two are available for initial coordination of aspartic acid as bidentate ligand. In addition to this, 1,6-dah six-membered chelate ring precludes the necessary movement of the five-membered chelate ring backbone so that the linear triamine isomerization is stereospecific. Any mer→ fac intramolecular rearrangement involves the six-membered chelate ring part of 1,6-dah. Stereospecificity is also controlled by the aspartic acid chirality.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::799cfddf3ad9b6be64b77da388d5057f https://doi.org/10.1135/cccc19882654 Zobrazit plný text záznamu