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Alternating Right‐ and Left‐Handed Helical Loops in a Self‐Assembled Polymer: Direct Observation of Ring‐Opening Polymerization of a Macrocyclic Gold Complex
Author(s) -
Qin Zengquan,
Jennings Michael C.,
Puddephatt Richard J.
Publication year - 2002
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20020201)8:3<735::aid-chem735>3.0.co;2-h
Subject(s) - ring (chemistry) , polymer , polymerization , chemistry , helix (gastropod) , crystallography , ring opening polymerization , polymer chemistry , stereochemistry , organic chemistry , ecology , snail , biology
Reaction of the ligand N,N′‐ bis(pyridin‐3‐yl)‐1,3‐benzenedicarboxamide ( 1 ) with the diphosphanedigold( I ) complex [( μ ‐PP)(AuO 2 CCF 3 ) 2 ] occurred by displacement of the trifluoroacetate ligands by the pyridyl groups of 1 , and crystallization gave the macrocyclic complex [Au 2 ( μ ‐PP)( μ ‐ 1 )](CF 3 CO 2 ) 2 ( 2 b ), when PP= trans ‐[Ph 2 PCH=CHPPh 2 ] but the polymer [{Au 2 ( μ ‐PP)( μ ‐ 1 )} x ](CF 3 CO 2 ) 2 x ( 3 ), when PP=Ph 2 PCH 2 CH 2 PPh 2 . The polymer 3 contains a series of helical turns connected by linear chain sections, and the helices have alternating right‐ and left‐handed conformations. The polymer 3 dissolves to give an equilibrium mixture of the macrocyclic ring complex [Au 2 ( μ ‐PP)( μ ‐ 1 )](CF 3 CO 2 ) 2 ( 2 a ), and ring‐opened oligomers, thus giving insight into the mechanism of the ring‐opening polymerization reaction.