Pressure-Induced Polymerization of Crystalline and Amorphous 3-Nitrophenylacetylene

Pressure-induced polymerization (PIP) of crystalline and amorphous 3-nitrophenylacetylene (3-NPA), formed by controlling the average compression rate, was investigated by using in situ Raman spectra and Fourier transform infrared spectroscopy. The results suggest that the threshold pressure for the alkynyl polymerization reaction found in the crystalline phase was about 11.8 GPa, whereas polymerization occurred at 6.2 GPa in the amorphous phase. The hydrogen transfer reaction was observed during these decompression processes. The crystal structure of 3-NPA at 12.0 GPa was solved, and the distances between alkynyl groups were calculated. Our research demonstrates that one poly(phenylacetylene) derivative can be synthesized at lower pressures from the amorphous phase, providing some inspiration for future pressure-induced polymerization.