Thermally induced dimensionality changes in derivatives of a "super stable" Blatter radical

Bruno Camargo; Irina Zajcewa; Anna Pietrzak; Emilia Obijalska; Jacek Szczytko; Piotr Kaszyński

doi:10.1039/d3cp01298k

Thermally induced dimensionality changes in derivatives of a "super stable" Blatter radical

Phys Chem Chem Phys. 2023 Aug 30;25(34):22813-22818. doi: 10.1039/d3cp01298k.

Authors

Bruno Camargo¹, Irina Zajcewa², Anna Pietrzak³, Emilia Obijalska⁴, Jacek Szczytko¹, Piotr Kaszyński^{4

5

6}

Affiliations

¹ Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland.
² Institute of Physics, Polish Academy of Sciences, 02668 Warsaw, Poland.
³ Faculty of Chemistry, Łódź University of Technology, 90-924 Łódź, Poland.
⁴ Faculty of Chemistry, University of Łódź, 91-403 Łódź, Poland.
⁵ Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, 90-363 Łódź, Poland.
⁶ Department of Chemistry, Middle Tennessee State University, Murfreesboro, TN, 37130, USA. piotr.kaszynski@mtsu.edu.

PMID: 37584108
DOI: 10.1039/d3cp01298k

Abstract

Two derivatives of a "super stable" Blatter radical (1,3-diphenyl-7-trifluoromethyl-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl) with N(1)-Ar = 2-CF₃C₆H₄ and 2-MeOC₆H₄ were obtained and investigated using XRD and SQUID magnetometry methods. The investigation revealed strong antiferromagnetic interactions in both radicals, which are described using the Hatfield model. For the latter radical, an abrupt and reversible change in the χ(T) plot was observed at 29 K. It was ascribed to a structural transition, consistent with a two-dimensional to one-dimensional thermally activated crossover, as supported by specific heat measurements (C_vHvs. T). It is suggested that the transition is related to an order-disorder transition of the CF₃ group, which is corroborated using XRD structural analysis.