Thermochromic phase transition of a polydiacetylene, poly(ETCD), studied by high-resolution solid-state carbon-13 NMR

Synthesis of ladder polymers containing polydiacetylene backbones connected with methylene chains and their optical properties

“…For CP/MAS spectra, the CH 2 peak of external adamantane was set at 29.5 ppm from tetramethylsilane as a 13 C chemical shift. The powder X-ray diffraction (XRD) patterns were recorded on a Mac Science M18XHF 22 -SRA using CuK␣ radiation. The thickness of the polymer films was measured by using a Tencor Instruments Alpha-Step profiler.…”

“…Tanaka et al 22 reported that the thermochromic phase transition between blue and red phases of PDA from ETCD [R ϭ O(CH 2 ) 4 OOCONHCH 2 CH 3 ] could be explained by the electronic structure change of PDA backbone due to a certain strain produced by the hydrogen-bonding side chains. Thus, we investigated the IR absorption spectra of all monomers and polymers in solid state.…”

Rational Design of Conjugated Polymer Supramolecules with Tunable Colorimetric Responses

“…[84] However, observations made with AFM images of the blueand red-phase PDAs confirm the alkyl chains in red-phase PDAs exist in a more ordered state. [85] The observations made with AFM images, 13 C NMR data reported by Tanaka et al, [86] and theoretical calculations from Tripathy et al, [78] have led to the suggestion that the shear forces imposed on the PDA film induce sidechain rotation about the conjugated backbone which reduce the effective conjugation length of the polymer.…”

Dissolution and Spectroscopic Properties of the Polydiacetylene Poly(10,12-docosadiyne-1,12-diol-bisethylurethane)

“…[1,2,5] This was shown to be incorrect by 13 C NMR in solutions and solid samples. [24,37,38] It was also assumed that the transitions between the ordered red-and bluephases and the disordered yellow-phase of nBCMU polymers were associated with the complete disruption of the hydrogen bonds between the side-groups. [3,5,37,39] However, doubt was cast on the analysis of the IR spectral data used to support this conclusion.…”