¹²³Te and ¹²⁵Te Fourier Transform NMR Investigations

Abstract

The NMR signals of 123Te and 125Te have been observed in solutions of K2TeO3 and Na2TeO3 in D2O. In these solutions the ratios of Larmor frequencies ν(125Te)/ν(123Te), ν(125Te)/v(2H) and ν(125Te)/ν(23Na) have been determined with high accuracy. With the measured chemical shifts of 2H, 23Na, 125Te relative to infinitely diluted solutions the ratios of the Larmor frequencies are extrapolated and values of the magnetic moments are given. The relaxation times T1 and T2 are very different for 125Te in TeO32-: a ratio T1/T2 of 8.2 ± 0.4 has been found. No nuclear Overhauser effect due to dipole-dipole interaction of 125Te with the water protons has been detected.

77Se and125Te nuclear magnetic resonance investigations in II?VI and IV?VI compounds

“…With the known concentration dependence of the 125Te signal in the tellurite solution [16], these chemical shifts have been extrapolated to infinite dilution. The tellurite signal is favourable as reference signal, because relatively concentrated solutions are possible, further the linewidths is only a few Hz and the line-position is only weakly depending on the concentration [16].…”

“…With the known concentration dependence of the 125Te signal in the tellurite solution [16], these chemical shifts have been extrapolated to infinite dilution. The tellurite signal is favourable as reference signal, because relatively concentrated solutions are possible, further the linewidths is only a few Hz and the line-position is only weakly depending on the concentration [16]. The values of the chemical shifts and of the linewidths of the tellurides are given in Table 1 together with values of P,, A P and -6/A P. The value of P, for the K2TeO a solution has been extrapolated by combining the results of Willig and Sapoval [7] and the chemical shifts of this work and is the same as that given by Willig and Sapoval [7] for TeC12 dissolved in aqua regia.…”

“…In this paper we report the detection of NMR signals of VTSe in ZnSe, CdSe, HgSe and PbSe as well as of 125Te in ZnTe, CdTe, HgTe and PbTe referring the chemical shifts to aqueous solutions of Na2SeO 3 resp. K2TeO 3, the NMR parameters of which are well known [16,17]. One of the aims of this investigation is to test the theory of Willig and Sapoval [7] also for selenium.…”