A 400 MHz NMR spectrometer to support chemistry at Sheffield

NMR光谱是表征新化合物和材料的基本技术，也是任何从事合成化学的部门的核心设施。最近谢菲尔德化学系的一系列新任命，以及一系列正在进行的新项目，导致过去5年对我们的老年机器套件的需求增加了100%。此应用程序是一个400兆赫的仪器，将专门用于特别是非常规实验（1H或13 C以外的原子核;二维实验，特别是涉及1H/19 F等不同原子核的实验;大分子和聚合物的扩散研究;变温分析），因此不能不使用大马力快速周转服务机。新仪器需要进行的研究包括：（1）研究了带正电荷的笼状大分子与带负电荷的物种在其中心空腔结合的主客体化学;（2）研究了手性有机锂试剂的溶液结构（3）测量新聚合物材料的许多性质，如它们形成的速率;其中单体组分的组成;聚合物分子在溶液中的尺寸分布;由于酸度的变化而引起的胶束的溶胀程度。(4)与CO在体内缓释有关的具有药物应用的金属羰基络合物的溶液结构和分解速率的测定（5）弱相互作用强度的精确测定（氢键，分子间F-F接触）在不同温度下的溶液中（6）结晶过程中非常早期事件的测量，由此溶液中的分子开始结合成低聚物组装体，其作为随后晶体生长的“成核点”。(7)研究了具有不寻常物理性质的大型多卟啉组装体的溶液结构、尺寸和形成速率。

NMR spectroscopy is an essential technique for characterising new compounds and materials and is a core facility in any department undertaking synthetic chemistry. A recent series of new appointments in the chemistry department at Sheffield, and a range of new projects being undertaken, has resulted in a 100% increase in the demand on our elderly suite of machines in the last 5 years. This application is for a 400 MHz instrument which will be dedicated in particular to non-routine experiments (nuclei other than 1H or 13C; two-dimensional experiments, especially involving different nuclei such as 1H/19F; diffusion studies on macromolecules and polymers; variable-temperature analyses) for which the workhorse fast-turnaround service machine cannot be spared.Studies to be undertakne on the new instrument include(1) Examination of the host-guest chemistry of large positively-charged cage-like molecules which bind negatively charged species in their central cavities;(2) Examination of the solution structure of chiral organolithium reagents (essential intermediates in organic chemistry), and measurement of the rate at which the optical isomers interconvert;(3) Measurements of many properties of new polymeric materials, such as the rates at which their form; the composition of monomer components in them; the size distibution of the polymeric molecules in solution; the degree of swelling of micelles due to changes in acidity.(4) Measurements on the solution structures and rates of decomposition of metal carbonyl complexes which have pharmacetical applications associated with the slow release of CO 'in vivo'(5) Accurate determination of the strengths of weak interactions (hydrogen bonds, intermolecular F---F contacts) in solution at different temperatures(6) Measurement of very early events in the process of crystallisation, whereby molecules in solution begin to associate into oligomeric assemblies which act as 'nucleation points' for subsequent growth of crystals.(7) Examination of the solution structures, sizes, and rates of formation of large multi-porphyrin assemblies which have unusual photophysical properties.