Acquisition and Analysis of HMBC Data of Unknown Organic Compounds

Shelby Temple

A critical component of chemical research in the medicinal and natural products fields is the determination of an unknown compound's structure. Nuclear magnetic resonance spectroscopy (NMR) is commonly employed for structural elucidation. The two most commonly used types of NMR are one-dimensional (1D NMR) and 2-dimensional (2D NMR) techniques. Heternuclear Multiple Bond Correlation (HMBC), a 2D NMR experiment, is being used with increasing frequency in professional research, because it reveals 2-, 3-, and 4- bond 13C-1H correlations, enabling assembly of the hydrocarbon backbone. However, SOU does not currently employ HMBC in structural analysis. To determine the feasibility of adding HMBC to research and/or an advanced spectroscopy course at SOU, HMBC was employed to determine the structure of two organic compounds (phenyl allyl ether and 1-penten-3-ol). Both 1D (1H, 13C, and DEPT-135) and 2D (COSY (1H-1H 3-bond correlations), HSQC (13C-1H 1-bond correlations), and HMBC) NMR spectra of these molecules were collected at two different sample concentrations using a Bruker Avance 400 MHz spectrometer and processed using MestReNova. Early results indicate feasibility of adding the HMBC experiment to SOU's spectroscopy repertoire and optimization of the pulse program is currently underway.