biostudies-literatureJia SResearch Institute Centers, New York University Abu DhabiNatural Science Foundation of Tianjin MunicipalityNational Natural Science Foundation of ChinaNew York University Abu Dhabi1036-1047https://www.ebi.ac.uk/biostudies/studies/S-EPMC12933368biostudies-literatureUnknown6(2)The melting point is one of the most fundamental properties of crystalline materials and has been commonly used to determine the chemical and phase purity of organic compounds. Here, we report a significant depression in the melting point of about 1.4 K in naturally grown crystals with a circular shape obtained for one polymorph of the tetradecamorphic compound 5-methyl-2-((2-nitrophenyl)-amino)-3-thiophenecarbonitrile (ROY). Crystals of ROY grown by microspace sublimation have peculiar habits, with irregular, elongated, occasionally bent, or curled habits, and with one or both of their ends closed into loops. In contrast to the straight crystals, the Mueller matrix microscopic analysis suggested the continuous reorientation of electrical dipole moments in the curled crystals. When heated,JACS AuDepression of the Melting Point in Naturally Grown Circular Crystals.PMC1293336822278300222740562247828422JCZDJC00040AD073CG011Naumov PLiu JJia SAhmed ECui XWang YTang WGong JSu XLi LfalseDepression of the Melting Point in Naturally Grown Circular Crystals.The melting point is one of the most fundamental properties of crystalline materials and has been commonly used to determine the chemical and phase purity of organic compounds. Here, we report a significant depression in the melting point of about 1.4 K in naturally grown crystals with a circular shape obtained for one polymorph of the tetradecamorphic compound 5-methyl-2-((2-nitrophenyl)-amino)-3-thiophenecarbonitrile (ROY). Crystals of ROY grown by microspace sublimation have peculiar habits, with irregular, elongated, occasionally bent, or curled habits, and with one or both of their ends closed into loops. In contrast to the straight crystals, the Mueller matrix microscopic analysis suggested the continuous reorientation of electrical dipole moments in the curled crystals. When heated,2026-01-01T00:00:00Z2026 Feb2026-07-16T22:12:19.679Z2026-07-12T03:06:52.41ZS-EPMC129333684175582510.1021/jacsau.5c01455