NMR Part 1 Solutions: #3

3.* (1996 F 3) Adenosine triphosphate, "ATP," is often called the energy currency of aerobic organisms. Oxidative phosphorylation results in energy stored by ATP; hydrolysis of ATP to ADP and phosphate releases energy. Below is a structural formula of ATP. Sketch the ³¹P NMR spectrum you might expect to be manifest by ATP; note that ³¹P (100% natural abundance) has nuclear spin 1/2. Do not ignore spin-coupling.

We expect two doublets and a doublet of doublets to appear on the NMR spectrum. The right-most P and is not affected by coupling with H due to distance and the different energy of this splitting. The middle P is responsible for the doublet of doublets. If the P’s are labeled A, B, C from left to right, then the spectrum is assigned as follows: