{"title":"嘧啶碱:胸腺嘧啶和尿嘧啶的低温热力学性质","authors":"Michael A. Bespyatov*, ","doi":"10.1021/acs.jced.5c00389","DOIUrl":null,"url":null,"abstract":"<p >This study reports precise heat capacity data for crystalline thymine (C<sub>5</sub>H<sub>6</sub>N<sub>2</sub>O<sub>2</sub>; CAS Number: 65-71-4; fraction purity: 0.999) and uracil (C<sub>4</sub>H<sub>4</sub>N<sub>2</sub>O<sub>2</sub>; CAS Number: 66-22-8; fraction purity: 0.999) over the temperature range of 6 to 330 K. Adiabatic calorimetry was used to perform the measurements. The calorimeter was validated by measuring the heat capacity of reference standards (copper and benzoic acid). The experimental heat capacity data were fitted using Einstein-Planck functions and extrapolated to 0 K following the Debye law. The data enabled the calculation of thermodynamic functions (entropy, enthalpy increment, and reduced Gibbs energy) for thymine and uracil between 0 and 330 K.</p>","PeriodicalId":42,"journal":{"name":"Journal of Chemical & Engineering Data","volume":"70 9","pages":"3630–3637"},"PeriodicalIF":2.1000,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Low-Temperature Thermodynamic Properties of Pyrimidine Bases: Thymine and Uracil\",\"authors\":\"Michael A. Bespyatov*, \",\"doi\":\"10.1021/acs.jced.5c00389\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >This study reports precise heat capacity data for crystalline thymine (C<sub>5</sub>H<sub>6</sub>N<sub>2</sub>O<sub>2</sub>; CAS Number: 65-71-4; fraction purity: 0.999) and uracil (C<sub>4</sub>H<sub>4</sub>N<sub>2</sub>O<sub>2</sub>; CAS Number: 66-22-8; fraction purity: 0.999) over the temperature range of 6 to 330 K. Adiabatic calorimetry was used to perform the measurements. The calorimeter was validated by measuring the heat capacity of reference standards (copper and benzoic acid). The experimental heat capacity data were fitted using Einstein-Planck functions and extrapolated to 0 K following the Debye law. The data enabled the calculation of thermodynamic functions (entropy, enthalpy increment, and reduced Gibbs energy) for thymine and uracil between 0 and 330 K.</p>\",\"PeriodicalId\":42,\"journal\":{\"name\":\"Journal of Chemical & Engineering Data\",\"volume\":\"70 9\",\"pages\":\"3630–3637\"},\"PeriodicalIF\":2.1000,\"publicationDate\":\"2025-08-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Chemical & Engineering Data\",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acs.jced.5c00389\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Chemical & Engineering Data","FirstCategoryId":"1","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.jced.5c00389","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Low-Temperature Thermodynamic Properties of Pyrimidine Bases: Thymine and Uracil
This study reports precise heat capacity data for crystalline thymine (C5H6N2O2; CAS Number: 65-71-4; fraction purity: 0.999) and uracil (C4H4N2O2; CAS Number: 66-22-8; fraction purity: 0.999) over the temperature range of 6 to 330 K. Adiabatic calorimetry was used to perform the measurements. The calorimeter was validated by measuring the heat capacity of reference standards (copper and benzoic acid). The experimental heat capacity data were fitted using Einstein-Planck functions and extrapolated to 0 K following the Debye law. The data enabled the calculation of thermodynamic functions (entropy, enthalpy increment, and reduced Gibbs energy) for thymine and uracil between 0 and 330 K.
期刊介绍:
The Journal of Chemical & Engineering Data is a monthly journal devoted to the publication of data obtained from both experiment and computation, which are viewed as complementary. It is the only American Chemical Society journal primarily concerned with articles containing data on the phase behavior and the physical, thermodynamic, and transport properties of well-defined materials, including complex mixtures of known compositions. While environmental and biological samples are of interest, their compositions must be known and reproducible. As a result, adsorption on natural product materials does not generally fit within the scope of Journal of Chemical & Engineering Data.