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Two stereoregular 2D polyesters were synthesized by using topochemical polymerization of symmetric four-armed monomers. The monomers contain reactive carbon–carbon double bond(s) on each arm. The critical assemblies with multiple preorganized reactive centers were characterized by powder and single crystal X-ray diffraction. The solvent-free polymerization could be carried out with sunlight or UV irradiation. The locally confined photopolymerization process dimerized all of the olefins within the 2D bricklayer packing, which led to the formation of 2D polymers in the solid state. The process was monitored by FT-IR, and the products were confirmed by solid state NMR. After hydrolysis of the 2D polyester, the newly formed carbon–carbon single bonds during the [2 + 2] photocyclization were directly revealed by the single crystal structure of the hydrolysis product. Ultrathin sheets of the 2D polymer were observed under SEM and TEM after exfoliation.

The NMR spectra of taxadiene are assigned in Section 4.1 . Section 4.2 presents the logical methodology by which the structure of the twenty-carbon-containing isooxacyclotaxane (isoOCT) is deduced.

Dopant uptake in sodium-doped poly( p -phenylene vinylene) (PPV) has been measured, and e.s.r. spectroscopy has been used to follow the changes in unpaired spin concentration as the doping reaction proceeds. 2 H n.m.r. line shapes of sodium-doped, ring-deuterated PPV (PPV-d 4 ) have also been studied to observe the effects of doping. They contain two distinct components, one of which is attributed to hydride formation. The overall pattern is insensitive to temperature changes.

Phenylene ring-deuterated poly(p-phenylenevinylene) films were prepared from water-cast films of the precursor polymer and were heated and stretched to effect simultaneous orientation and elimination. 2 H quadrupole echo NMR spectra have been obtained from these films, aligned at an angle in the NMR magnetic field, for various draw ratios. The experimental data from 2 H spectra have been simulated with excellent agreement and thereby have yielded the chain orientation distribution in these films

All phenylene rings of an annealed poly(phenylene vinylene) (PPV) film are shown to be capable of undergoing 180° rotation jumps about the 1,4-phenylene ring axis. The dependence of the median jump rate on temperature can be described by an Arrhenius equation with an activation energy of 15kcal/mol. The phenylene rings of PPV show relatively homogeneous behavior and the observed distribution of ring flip rates could be caused by a maximum distribution of activation energies of ±2 kcal/mol.

Ring-deuterated poly( p -phenylene vinylene) has been doped with concentrated sulphuric acid and examined with 2 H quadrupole echo nuclear magnetic resonance spectroscopy. Doping is observed to change the relative population of fast versus slow flipping p -phenylene rings. This relationship has been investigated over a range of temperatures. Modelling this system as a two-site chemical exchange shows that the change in the relative populations of fast versus slow ‘flippers’ corresponds to an increase in the activation energy for the 180° ring flip. The width of the distribution of flip rates is also observed to increase upon doping. At elevated temperatures the samples studied undergo a significant loss of mass which corresponds to a loss of dopant. The chemistry of this process is examined.

Solid-state 13C cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectra have been obtained for annealed films of poly (p-phenylene vinylene) (PPV), prepared through the precursor route and for a deuterated PPV-d4, poly (p-2,3,5,6 tetradeuterophenylene vinylene). 13C CPMAS spectra of PPV are of high resolution, typically characteristic of a nearly fully crystalline structure. All four phenylene and vinylene resonances have been assigned, and for stretched films the 13C CPMAS linewidth and the quality of crystallinity are independent of the draw ratio. 13C CPMAS resolution and crystallite size (as determined by transmission electron microscopy, TEM) depend upon final annealing temperature. The greatest NMR resolution and largest crystallite size are obtained for films annealed at 300°C. The 13C CPMAS NMR spectra show the presence of phenylene ring 180° rotational jumps, and 13C CPMAS resolution is affected by rotational disorder about phenylene-vinylene bonds. NMR data show that PPV films possess molecular motion at elevated temperatures. Enhancement of this motion during annealing may provide a means for improving the quality of PPV crystallinity.