The ratio of the quadrupole moments of the isotopes95Mo and97Mo

The spin-lattice relaxation timesT ₁ of the NMR signals of⁹⁵Mo and⁹⁷Mo in aqueous K₂MoO₄ solutions were determined by the inversion recovery technique. To separate the relaxation rates due to electric quadrupole interaction and due to magnetic dipole interaction, pure H₂O and mixtures of H₂O and D₂O were used as solvent. No dependence of the ratio of the relaxation ratesT ₁(⁹⁵Mo)/T ₁(⁹⁷Mo) on the composition of the solvent was to be detected, i.e. the relaxation due to magnetic dipole interaction may be neglected. From the ratio of the relaxation rates the absolute value of the ratio of the quadrupole moments of the molybdenum isotopes was evaluated: ¦Q(⁹⁷Mo)/Q(⁹⁵Mo)¦ = 11.4 ±0.3.