Separation ability and stoichiometry of cyclodextrin complexes.
Gas-liquid chromatography has been applied to search relations between selectivity towards isomers and stoichiometry of cyclodextrin complexes. The model tested compounds were: dimethylnaphthalenes and alpha- and beta-pinenes as constitutional isomers; cis/trans decalins, anetholes and isosafroles as diastereomers and as enantiomers (+/-)-alpha-pinenes and (+/-)-camphenes. Experimental retention data are used to confirm a simple theoretical model that allows distinguishing formation of G x CD complexes (1:1) and G x CD2 complexes (1:2). Based on the experimental data, stability constants K were evaluated. It has been found that remarkable selectivity factor alpha may appear both within the range of 1:1 stoichiometry (beta-CD complexes of decalins and of alpha- and beta-pinenes) and 1:2 stoichiometry (alpha-CD complexes with (+/-)-alpha-pinenes and (+/-)-camphenes). Occasionally selectivity arises from a different composition, when one isomer forms a 1:1 stoichiometry complex while another forms a 1:2 complex (dimethylnaphthalenes, cis/trans-anetholes and cis/trans-isosafroles).
Asztemborska
M
M
Institute of Physical Chemistry of the Polish Academy of Sciences, Warsaw.
Nowakowski
R
R
Sybilska
D
D
D000081248:Allylbenzene Derivatives; D000840:Anisoles / Q000737:chemistry / Q000302:isolation & purification; D002849:Chromatography, Gas; D003505:Cyclodextrins / Q000737:chemistry* / Q000302:isolation & purification*; D009281:Naphthalenes / Q000737:chemistry / Q000302:isolation & purification; D012451:Safrole / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism
D000081248:Allylbenzene Derivatives; D000840:Anisoles; D003505:Cyclodextrins; D009281:Naphthalenes; C006578:anethole; D012451:Safrole; C015959:isosafrole