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The 14N Quadrupole Coupling In Hexamethylene Triperoxide Diamine (Hmtd), John Persons, Gerard S. Harbison
The 14N Quadrupole Coupling In Hexamethylene Triperoxide Diamine (Hmtd), John Persons, Gerard S. Harbison
Gerard Harbison Publications
Using high-field NMR, we have determined the magnitude of the nuclear quadrupole interaction in hexamethylene triperoxide diamine (HMTD), the explosive allegedly used in the London bombings of July 2005. The experimental quadrupolar coupling constant, 5.334 MHz, is in good agreement with quantum chemical calculations. The predicted single zero-field transition frequency should lie in a relatively empty part of the 14N nuclear quadrupole resonance (NQR) spectrum; the spin relaxation rate is reasonably fast.
Slow Turning Reveals Enormous Quadrupolar Interactions (Streaqi), John Persons, Gerard S. Harbison
Slow Turning Reveals Enormous Quadrupolar Interactions (Streaqi), John Persons, Gerard S. Harbison
Gerard Harbison Publications
We introduce a new solid-state NMR method, which uses very slow sample rotation to visualize NMR spectra whose width exceeds feasible spectrometer bandwidths. It is based on the idea that if we reorient a tensor by a known angle about a known axis, the shifts in the NMR frequencies observed across the spectral width allow us to reconstruct the entire tensor. Called STREAQI (Slow Turning Reveals Enormous Anisotropic Quadrupolar Interactions), this method allows us to probe NMR nuclei that are intractable to current methods. To prove the concept and demonstrate its promise we have implemented the method for several 79Br …