Publications [#234589] of Warren S. Warren

Journal Articles
  1. Warren, WS; Goswami, D; Mayr, S, Laser enhanced NMR spectroscopy, revisited, Molecular Physics, vol. 93 no. 3 (1998), pp. 371-375 .

    Experimental investigations of the effects of moderately powerful (10-20 W cm-2) off-resonant continuous lasers on NMR spectra provide no evidence for the B(3) field recently proposed, or for any other mechanism which depends on the light polarization. Observed 1H and 13C line shifts with argon-ion laser irradiation for the molecule p-methoxyphenyliminocamphor mostly can be explained by heating effects. Residual shifts due to other mechanisms appear to be at most 0ยท1 Hz (5% of the linewidth). One mechanism which could account for residual shifts of this magnitude is differences between NMR frequencies in the excited (triplet) and ground electronic states, although our data have insufficient resolution to make definitive claims. However, it seems unlikely that this effect can be made sufficiently large to give practical resolution enhancements without massive heating.