{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,15]],"date-time":"2025-10-15T09:49:28Z","timestamp":1760521768264,"version":"3.37.3"},"reference-count":44,"publisher":"Wiley","issue":"10","license":[{"start":{"date-parts":[[2001,10,30]],"date-time":"2001-10-30T00:00:00Z","timestamp":1004400000000},"content-version":"vor","delay-in-days":302,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chirality"],"published-print":{"date-parts":[[2001,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>A number of variously monosubstituted 1,n\u2010diaza[n]paracyclophanes (n = 10\u201312), which show planar chirality and atropisomerism due to hindered rotation about single bonds, were synthesized via a classical route to analyze their stereodynamic properties. Racemic analytes with 10\u2010 and 11\u2010membered bridges were resolved by capillary zone electrophoresis (CZE) in acidic phosphate buffers (pH 2.5\u20134.5) employing permethylated \u03b2\u2010 and \u03b3\u2010cyclodextrin as chiral additives. Moreover, cyclodextrin mediated CZE was used in a discontinuously driven mode for investigations of the rotational interconversion process of conformationally labile homologues (n = 11). In stopped\u2010flow experiments, after baseline separation enantiomers were partially enantiomerized in situ inside the capillary by heating. The rate constants (<jats:italic>k<jats:sub>enan<\/jats:sub><\/jats:italic>= \u00bd<jats:italic>k<jats:sub>rac<\/jats:sub><\/jats:italic>) and rotational energy barriers (\u0394<jats:italic>G<\/jats:italic><jats:sup>\u2260<\/jats:sup>) were determined from the resulting enantiomeric ratios. Energy barriers between 113\u2013126 kJ\/mol were found depending on the substituent of the benzene ring and the degree of ionization of the amino groups in bridgehead positions. The energy barriers increased in order of the substituents: NO<jats:sub>2<\/jats:sub>&gt;&gt; CF<jats:sub>3<\/jats:sub>&gt; Br &gt; Cl &gt; CH<jats:sub>3<\/jats:sub>\u2248 F. In addition, the rotational energy barriers were decreased by approximately 6\u20138 kJ\/mol in the presence of the chiral selector. Chirality 13:679\u2013690, 2001. \u00a9 2001 Wiley\u2010Liss, Inc.<\/jats:p>","DOI":"10.1002\/chir.10024","type":"journal-article","created":{"date-parts":[[2002,8,25]],"date-time":"2002-08-25T21:15:54Z","timestamp":1030310154000},"page":"679-690","source":"Crossref","is-referenced-by-count":23,"title":["Synthesis, resolution, and investigation of the rotational interconversion process of atropisomeric 1,n\u2010diaza[n]paracyclophanes using cyclodextrin\u2010mediated capillary zone electrophoresis"],"prefix":"10.1002","volume":"13","author":[{"given":"Klaus P.","family":"Scharw\u00e4chter","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Detlev H.","family":"Hochmuth","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Helmutt","family":"Dittmann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wilfried 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