High-pressure transformation of dithiazolylidene-dithiazolium polyiodide with N-H center dot center dot center dot N hydrogen bond: A Raman Spectroscopy study

https://doi.org/10.1016/j.saa.2021.120635

The insight into the behavior of polyiodides under non-ambient conditions can enrich the practical applications due to obtaining materials with adjustable and tunable conducting properties. In this work Raman spectroscopy study in the range 0 – 6.5 GPa has been performed for dithiazolylidene-dithiazolium zigzag polyiodide with N-H…N hydrogen bond. Variations of band positions in the low-wavenumber region of Raman spectra have been attributed to the changes in the anionic part of the unit cell. The association of different interacting polyiodide subunits at pressure above 1.5 GPa leads to the emergence of the bands at 98 and 115 cm⁻¹ due to consistent vibrations in the I₈^2- zigzag. The emergence of the band at 159 cm⁻¹ above 0.28 GPa can be assigned to N-H…N hydrogen bond vibration. The obtained results depict undergoing structure transformations: the stronger are cation…cation and anion…anion interactions the more likely is the observation of conducting properties due to the formation of polyiodide zigzag and strongly-bound hydrogen-bonded fragment.