Premium
Photoresponsive Piperazine Macrocycles
Author(s) -
Huuskonen Juhani,
Schulz Jürgen,
Kolehmainen Erkki,
Rissanen Kari
Publication year - 1994
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.1491271127
Subject(s) - chemistry , piperazine , molecule , ring (chemistry) , solvent , crystallography , solid state , stereochemistry , polymer chemistry , organic chemistry
The photoresponsive macrocyclic phanes 3, 7a, 7b, 10 were prepared. The ( E ) and ( Z ) isomers of 7b could be separated from each other by column chromatography. The X‐ray structure of the 31‐membered cycle ( E )‐ 7b and the 54‐membered cycle ( E,E )‐ 10 shows a tendency toward self‐assembly to a dimeric structure ( 7b ) and a tubular structure ( 10 ) in the crystalline state. Additionally, both structures demonstrate inclusion of solvent molecules into the cavity (diameter 5 Å, 7b ) and tube (diameter 11 Å, 10 ) respectively. A variable‐temperature 1 H‐NMR study of 7b showed that the piperazine ring inversion is restricted at lower temperatures.