The purity of SnCl4 as monitored by Cl-35 nuclear quadrupole resonance

The nuclear quadrupole resonance (NQR) spectroscopy was used to control the comparative purity of three SnCl4 samples subjected to successive stages of deep purification. The results showed that at 77 K the samples were identical in purity degree due to the 'freezing' of impurities into a separate fraction not affecting the perfection of the SnCl4 crystal lattice. The results of relaxation measurements suggest that paramagnetic impurity atoms (Fe and Cr) contained in the samples in small amounts might be embedded into the crystal lattice causing extremely long spin-spin relaxation time.