Premium
Effect of Through‐Bond Interaction on Conformation and Structure in Rod‐Shaped Donor–Acceptor Systems. Part 2.
Author(s) -
De Ridder Dirk J. A.,
Goubitz Kees,
Schenk Henk,
Krijnen Bert,
Verhoeven Jan W.
Publication year - 2003
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200390082
Subject(s) - piperidine , chemistry , ring (chemistry) , aryl , crystallography , cyclohexane conformation , stereochemistry , crystal structure , acceptor , hydrogen bond , molecule , organic chemistry , physics , condensed matter physics , alkyl
The crystal structures of seven N ‐aryltropan‐3‐one (=8‐aryl‐8‐azabicyclo[3.2.1]octan‐3‐one) derivatives 1T1, 2T1, 2T2, 3T2, 5T2, 2T3 , and 3T3 are presented ( Fig. 2 and Tables 1 – 5 ) and discussed together with the derivatives 1T2 and 4T2 published previously. The piperidine ring adopts a chair conformation. In all structures, the aryl group is in the axial position, with the plane through the aryl C‐atoms nearly perpendicular to the mirror plane of the piperidine ring. The through‐bond interaction between the piperidine ring N‐atom (one‐electron donor) and the substituted exocyclic CC bond (acceptor) not only elongates the central CC bonds of the piperidine ring but also increases the pyrimidalization at C(4) of the piperidine ring. Flattening of the C(2)–C(6) part of the piperidine ring decreases the through‐bond interaction.