Synthesis and structural determination of thermochromic compound

Abstract

Thermochromic materials are extensively utilized in various fields, such as healthcare, textiles, and military applications. The exceptional thermal properties of these materials are attributed to the thermochromic substances they contain. Lactone-based thermochromic compounds, known for their high sensitivity, broad color change range, and durability, have been extensively researched and developed. In this article, a thermochromic compound, crystal violet lactone (CVL), chemically identified as 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide, was prepared through two steps by the reaction of N,N-dimethylaniline, m-dimethylaminobenzoic acid, and p-dimethylamino-benzaldehyde in acid condition. CVL exists in white powder, melting point 180 - 183 ^oC, yield 61.6%. The product structure was determined by modern physical methods such as IR, 1D NMR, 2D NMR, and MS spectra.