The reaction products of vinylidenefluoride (VDF) with methanol as a telogen have been analysed in the solution state by H-1 and F-19 nuclear magnetic resonance (NMR) spectroscopy. High-resolution F-19 and H-1 NMR spectra were achieved using high-power H-1 and F-19 clecoupling, respectively, giving superior resolution and revealing previously unresolved signals of the vinylidenefluoricle telomer (VDFF). H-1 and F-19 homo- and hetero-nuclear scalar coupling constants are presented and the spectra of functional groups and reverse units (including the identification of short-chain structures) are discussed. Furthermore, the application of F-19 or H-1 decoupling for the correct assessment of reverse-unit content and degree of polymerisation is demonstrated. This work highlights the need for high-resolution NMR spectroscopy to determine both the chemical structure and the composition of these important fluoropolymers. (c) 2008 Elsevier Ltd. All rights reserved.