Variable Temperature Diffraction

变温衍射

• 批准号: RTI-2023-00111
• 负责人: Bohle, david
• 金额: $ 8.43万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=747788
• 关键词: Variable; Temperature; Diffraction

We propose to purchase a variable temperature cryostat for our single crystal X-ray diffractometer. This is a critical piece of infrastructure which is required for the NSERC supported innovative research in the applicant's labs. Temperature has a significant effect on the diffraction of x-rays with lower temperatures leading to significantly enhanced(stronger) reflection intensities, and often better defined thermal parameters. For fluorinated and halogenated compounds these temperature effects become significant and can lead to a temperature dependent loss of high angle peaks and thus resolution of the final structure. This can make a difference in the acceptability of a structure result during review and thus final publication. Significantly though, the use low temperature is now routine in many facilities due to systematic improvements in the data collected and the final models. In addition to these factors, many compounds undergo temperature dependent phase transitions and control of the temperature is critical for the determination of these phases. The instrument to be purchased is an Oxford 1000 low temperature cryostat which replace a failed and irreparable Bruker Cryostream unit fitted onto an ApexII Bruker diffractometer. This twenty year old unit has been repaired twice(by Bruker) and deemed irreparable after the last technicians visit in 2019. This infrastructure will not only support the three CoPI's of this application but be used to train an average of 17 HQP annually. It will be open to other users and it will support much our current research and the continued frontline research described in this proposal.

我们建议为单晶X射线衍射仪购买可变温度低温恒温器。这是申请人实验室中Nserc支持的创新研究所必需的基础设施的关键部分。温度对温度较低的X射线的衍射具有显着影响，从而导致显着增强（更强）的反射强度，并且通常更好地定义了热参数。对于氟化和卤化化合物，这些温度效应变得显着，并可能导致高角度峰的温度损失，从而消除最终结构。这可以改变审查过程中结构结果的可接受性，从而最终出版。但是，由于收集到的数据和最终模型的系统改进，现在在许多设施中，使用低温现在是常规的。除这些因素外，许多化合物经历了依赖温度的相变和温度的控制对于确定这些阶段至关重要。要购买的仪器是牛津1000低温低温恒温器，它取代了安装在Apexii Bruker衍射仪上的失败且无法弥补的Bruker冷冻流式单元。这个二十岁的单位已由布鲁克（Bruker）进行了两次维修，并在2019年上一次技术人员访问后被认为是无法弥补的。该基础设施不仅将支持本申请中的三个COPI，而且每年平均训练17 hqp。它将向其他用户开放，它将支持我们当前的许多研究以及本提案中所述的持续前线研究。