QUANTIFICATION OF 13C-OPTIMIZED CRYOGENICALLY-COOLED PROBES FOR CHEM RES

点击翻译按钮获取中文摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Tests are performed to quantify the utility of cryogenically-cooled probes for chemical research, especially with respect to obtaining directly-detected carbon-13 data. Highly unsaturated compounds are synthetic targets for a variety of research projects in the Chemistry Department at the UW-Madison. These compounds are sometimes difficult to characterize using inverse (proton-detected) methods now common with NMR analysis of complex compounds. Excellent techniques for total characterization that do not rely on the presence of 1H-13C J-couplings, such as INADEQUATE, have in the past required either 13C labeling or very high concentrations. The ability to obtain such data for moderately concentrated natural abundance compounds using a cryogenically-cooled probe, with the 13C preamp also cooled to reduce its noise factor, will be tested using NMRFAM's cryoprobe at 750 MHz. The utility of the probe for improving the acquisition of 1D 13C data will also be quantified.