INDOR spectra

W which have very low magnetogyric ratios. It is also possible to use triple resonance experiments to record heteronuclear INDOR spectra, as in the MINDOR and TINDOR experiments (109) (see p. 356), or to use a reasonably sensitive nucleus such as rather than the proton for detection. 

FIG. 4. accumulated INDOR spectra (. 2scans) of (McjSnjjSn Li. 3THF... 

FIG. 5. Oxygen-17 INDOR spectra of methanol enriched to 10mol obtained by monitoring the Me resonance in the proton spectrum. The frequency markers are in MHz and each trace is the result of 64 scans. Full line high frequency component of doublet monitored broken line low frequency component monitored. From ref 112. 

INDOR spectra with linewidths as small as 0-5 Hz have been obtained (370) from the monoprotiated impurities in commercial perdeuteriated solvents. 

Time-averaged INDOR spectra have given... 

The multiplicities observed in H- Si] INDOR spectra of methylsilicon halides enabled (388) Me3Si, Mc2Si, and MeSi species to be readily distinguished. However, in other derivatives only broad INDOR signals were observed. (389) 5( Si) values in Si-N (381, 384) and Si-Pt (390, 391) compounds have been measured. 

Copper has two naturally occurring isotopes both with spin I = j. Of these, Cu is the more abundant. Selective triple resonance H- P, Cu TINDOR spectra (109) were used to study ( Cu) in [(MeO)3P]4Cu. The lines observed are split into three in an analogous way to the doublet splitting observed when / = 1, as in INDOR spectra (398) (ref. 1). 

Organomercury compounds have been studied by double resonance (433, 433a) and H- Hg INDOR spectra were used in studies of the fluxional behaviour of two cyclopentadienylmercury derivatives. (434) The solvent and concentration dependence of <5( Hg) in i(Me0)2P(0)]2Hg has been investigated. (435)... 

Platinum-nitrogen couplings have been observed in H-J Pt] INDOR spectra of several complexes with N-donors such as thiocyanate and amines (Fig. 29). (175, 426, 427)... 

The different time-scales that are effective in the NMR spectra of different nuclei and their effects in double resonance experiments are illustrated in H-[ Pt INDOR spectra of the thiocyanate complexes present in the equilibrium (427)... 

The marked difference in signal-to-noise ratio between the traces obtained for the anomer and those found for the anomer illustrates nicely the compromise that has to be made between selectivity and sensitivity. A stronger monitoring, radio-frequency field could be used for the / anomer than for the a anomer, because the smallest splitting (separation of transitions 1 and 2) is considerably larger for the than for the a anomer and, even though the INDOR spectra of the a anomer can be obtained with a considerable sacrifice of signal intensity, there still exists some evidence of off-resonance effects, as indicated by occasional occurrence of more than the anticipated number of responses. 

Indirect Detection CW INDOR Spectra and FT Double Resonance Experiments... 

From INDOR spectra of Pb(CH3)4 measured In various solvents, the Influence of the solvents on the chemical shifts 5 ° Pb, determined as the total effect of the solvent on the nucleus, Is analyzed and compared with effects of the medium on 5 SI and values... 

Selective population transfer (SPT) and selective population inversion (SPI) are FT equivalents of INDOR in the sense that the same type of information is obtained, though not yielding spectra that look exactly like INDOR spectra. In SPT,... 

Three types of INDOR spectra can be observed. (1) Zero signal intensity is recorded at 5 if the field at 82 perturbs no frequency at all, or perturbs transitions which are not connected energetically with the transitions at 5. (2) A positive signal will be recorded when the observed 8 transition and the perturbed 82 transition have an energy level in common, which is intermediate between the two levels that are not in common. (3) A negative signal will be obtained when the perturbed and the monitored transitions share an energy level which is either above or below the other two levels. 

---