Many of the important recent advances in the area of NMR spectroscopy rely heavily upon high magnetic fields, state of the art radio frequency signal processing, and powerful computational ability. When very large molecules are under investigation, as in most biological applications of NMR, the complexity of the spectra are such that the maximum frequency separation of signals from chemically similar species is essential. The fact that the separation of such similar signals increases linearly with magnetic field is explicative of the intense effort in the industry to achieve higher and higher magnetic fields; however, it is clear that higher field alone is not enough to tackle the experimental problems involved when studying complex systems with NMR spectroscopy, and in fact it is often desirable to work at a lower magnetic field. To investigate complex systems, advanced one and two dimensional multiple-pulsed experiments have been, and continue to be, developed to allow the investigator to exploit a wide variety of intra-,and intermolecular interactions. Many of these experiments, including those presented in this proposal, require advanced instrumental and/or computational capability not currently available at the University of Nebraska-Lincoln. Examples of such capabilities are small (<90degree) rf.phase shifting, high speed, dynamic switching of transmitter and decoupler power, and the capability to handle large 2-dimensional data sets. The Department of Chemistry has concluded that both a 300 MHz and 500 MHz instrument incorporating state-of-the-art processing and probe design are essential to meet current and future research needs. The fact that our current NMR instrumentation is used to capacity to sustain the current routine needs of the department, and that the existing equipment cannot yield the necessary data in the research presented here, supports that conclusion.
