Nuclear Magnetic Resonance in Molecular Chlorine Compounds

Abstract

We have measured the chemical shifts, the transverse- and longitudinal-relaxation times of chlorine nuclear magnetic resonance of such liquid chlorine compounds as TiCl₄, VOCl₃, CrO₂Cl₂, and SiCl₄, of which the quadrupole coupling constants were measured by Dehmelt by means of the pure quadrupole resonance experiment. Our results were considered in view of the correlation to quadrupole coupling constant. Line widths are nearly proportional to the square of the quadrupole coupling constant. The equality of the transverse relaxation time T₂ and the longitudinal relaxation time T₁ has been verified experimentally in these compounds. Solomon’s method for the calculation of T₁ and T₂ was applied to a quadrupole relaxation. T₁ is exactly equal to T₂ in cases where quadrupole relaxation is essential, the molecular surroundings are isotropic, and further the extreme narrow conditions are well established. This result is identical to Wangsness and Bloch’s. Experimental T₁ values are about ten times larger than the theoretical one and the reason of the discrepancy is discussed. In Appendix, estimation of chemical shift by d-electron is given.