Structural deuterium isotope effects reveal the cooperativity of polymers

The signature characteristic of different kinds of polymers, synthetic and natural, is cooperativity arising from the recurring features common to all polymer structures. Cooperativity and amplification are simply different words expressing the same phenomenon leading one to expect that studies of polymers will allow small effects to be magnified, or, that is, for small effects to have surprisingly large effects on polymer properties. In the work reviewed in this short article we see this amplification at work in two different ways: (1) a synthetic polymer that forms a helical conformation but without preference for helical sense, right or left handed, is caused to take on a large excess of a single helical sense by incorporation of chiral information in surprising ways, including by forming chiral centers by deuterium substitution; (2) two polymers that mix homogeneously with each other by virtue of an unknown attractive interaction are revealed by deuterium labeling to be involved in a weak hydrogen bond between a hydrogen bound to aromatic carbon and an ethereal oxygen. Copyright © 2007 John Wiley & Sons, Ltd.