Kevin Linberg, Philipp C. Sander, Franziska Emmerling and Adam A. L. Michalchuk
{"title":"In situ investigation of controlled polymorphism in mechanochemistry at elevated temperature†","authors":"Kevin Linberg, Philipp C. Sander, Franziska Emmerling and Adam A. L. Michalchuk","doi":"10.1039/D3MR00019B","DOIUrl":null,"url":null,"abstract":"<p >Mechanochemistry routinely provides solid forms (polymorphs) that are difficult to obtain by conventional solution-based methods, making it an exciting tool for crystal engineering. However, we are far from identifying the full scope of mechanochemical strategies available to access new and potentially useful solid forms. Using the model organic cocrystal system of nicotinamide (NA) and pimelic acid (PA), we demonstrate with variable temperature ball milling that ball milling seemingly decreases the temperature needed to induce polymorph conversion. Whereas <strong>Form I</strong> of the NA:PA cocrystal transforms into <strong>Form II</strong> at 90 °C under equilibrium conditions, the same transition occurs as low as 65 °C during ball milling: a <em>ca</em> 25 °C reduction of the transition temperature. Our results indicate that mechanical energy provides a powerful control parameter to access new solid forms under more readily accessible conditions. We expect this ‘thermo-mechanical’ approach for driving polymorphic transformations to become an important tool for polymorph screening and manufacturing.</p>","PeriodicalId":101140,"journal":{"name":"RSC Mechanochemistry","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/mr/d3mr00019b?page=search","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"RSC Mechanochemistry","FirstCategoryId":"1085","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/mr/d3mr00019b","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Mechanochemistry routinely provides solid forms (polymorphs) that are difficult to obtain by conventional solution-based methods, making it an exciting tool for crystal engineering. However, we are far from identifying the full scope of mechanochemical strategies available to access new and potentially useful solid forms. Using the model organic cocrystal system of nicotinamide (NA) and pimelic acid (PA), we demonstrate with variable temperature ball milling that ball milling seemingly decreases the temperature needed to induce polymorph conversion. Whereas Form I of the NA:PA cocrystal transforms into Form II at 90 °C under equilibrium conditions, the same transition occurs as low as 65 °C during ball milling: a ca 25 °C reduction of the transition temperature. Our results indicate that mechanical energy provides a powerful control parameter to access new solid forms under more readily accessible conditions. We expect this ‘thermo-mechanical’ approach for driving polymorphic transformations to become an important tool for polymorph screening and manufacturing.
机械化学通常能提供传统溶液法难以获得的固体形态(多晶体),使其成为晶体工程中令人兴奋的工具。然而,我们还远未完全确定机械化学策略可用于获得新的、潜在有用的固态形式。通过使用烟酰胺(NA)和柚皮酸(PA)的有机共晶体模型系统,我们用变温球磨法证明,球磨似乎降低了诱导多晶型转换所需的温度。在平衡条件下,NA:PA 共晶体的形态 I 在 90 °C 时转变为形态 II,而在球磨过程中,同样的转变发生在低至 65 °C 的温度下:转变温度降低了约 25 °C。我们的研究结果表明,机械能提供了一个强大的控制参数,可以在更容易获得的条件下获得新的固体形态。我们希望这种驱动多晶体转变的 "热机械 "方法能够成为多晶体筛选和制造的重要工具。