Photoinduced and thermal denitrogenation of bulky triazoline crystals: Insights into solid-to-solid transformation

The photoinduced and thermal denitrogenation of crystalline triazolines with bulky substituents leads to the quantitative formation of aziridines in clean solid-to-solid reactions despite very large structural changes in the transition from reactant to product. Analysis of the reaction progress by powder X-ray diffraction, solid-state 13C CPMAS NMR, solid-state FTIR spectroscopy, and thermal analysis has revealed that solid-to-solid reactions proceed either through metastable phases susceptible to amorphization or by mechanisms that involve a reconstructive phase transition that culminates in the formation of the stable phase of the product. While the key for a solid-to-solid transformation is that the reaction occurs below the eutectic temperature of the reactant and product two-component system, experimental evidence suggests that those reactions will undergo a reconstructive phase transition when they take place above the glass transition temperature. © 2013 American Chemical Society.

Bulky substituents; Eutectic temperature; Experimental evidence; Powder X ray diffraction; Quantitative formation; Reconstructive phase transition; Solid-to-solid reaction; Two component systems; Fourier transform infrared spectroscopy; Metastable phases; Nuclear magnetic resonance spectroscopy; Thermoanalysis; X ray diffraction; Organic compounds; aziridine derivative; triazoline derivative; article; carbon nuclear magnetic resonance; chemical reaction; glass transition temperature; infrared spectroscopy; phase transition; photoinduced denitrogenation; solid to solid transformation; temperature; thermal analysis; thermal denitrogenation; X ray diffraction

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