Analysis of the unperturbed dimensions of the linear polyphosphate chain

Abstract
The unperturbed dimensions of the polyphosphate chain are interpreted using the rotational isomeric state theory of linear macromolecules. Rotation about one bond of the chain, while all its neighbours are trans, appears to be subject to little hindrance by either electrostatic or steric interactions. Simultaneous large rotations about pairs of adjoining bonds, irrespective of their relative signs, are impeded by both types of interactions. The unperturbed dimensions of the polyphosphate chain find satisfactory explanation on this basis.