In this work, the ¹H and ¹³C NMR spectra of 11 kinds of firstly synthesized N-substituted benzo-15-azacrown-5 and 3 bis-a3acrown ethers in different concentractions were lecorded. Individual peaks were assigned. Some structural effects were also discussed.

In this paper,new methods are suggested to measure indirectly T₁ and T₂ of ¹H connected to ¹³C. The methods can be used for the molecules whose ¹H spectra can not be resolved well. And we compare the result from indirect measurement with that from direct measurement.

A series of N-2,4-dinitrobenzenesulfenylbenzimidazoles has been prepared by the reaction of 2,4-dinitrobenzenesulfenylchloride with a series of 2-alkyl benzimidazoles and 5(6)-chloro-2-alkyl-benzimidazoles. Dynamic NMR spe-ctroscopy was used to measure the torsional barriers about the N-S bond,which were in the range of c.a. 19-20 kcal/mol. The torsional barriers reported here are among the highest yet observed for torsion about sulfenamide bonds.

The improvement on the double-side band FFT is presented, we use the method of the single-side band FFT to transform the doubleside band interfero-gram.The spectra transformed by the improved method are compared with those by the double-side band FFT and Forman's method, the results showed that this improved method is satisfactory and its computing speed is faster than the others, and the noise of the spectra still keep linear and random.

A study is described for the structural determination of polyperfluoro me-thylether with 56.4 MHz ¹⁹F NMR spectra. The assignments of 21 fluorine resonance lines and the sequence distribution of the polymer are given. A brief discussion about the end group structure is also included.

The chemical shifts and the spin-spin coupling constants of high-resolution NMR spectra of some three-, four-spin cases are caculated by using the trial-and-error method of the Euclidean Norm of Hamiltonian matrix. In this method., the experimental energy levels are used as the zero-order approximation of the Hamiltonian matrix so that the trouble of selecting primary chemical shifts and spin-spin coupling constants is avoided and only one resolution can be obtained

The results of high resolution NMR in solids by a routine high resolution spectrometer for liquids equiped with a MAS probe without any additional modification are reported in the paper, which show that routine high resolution NMR in solids, i.e. MAS and CPMAS with the existing routine spectrometers is optimistic.

The pulse-modulated double irradiation ¹H NMR method is used to determine the content of hydroxyl, ethoxyl and vinyl gruops bonded to the silicon atoms in poly (dimethyl siloxanes). Only in a few minutes (150 times accumulation) the 0.064% vinyl content in the polymer is detected with this method.
In present paper, the determined results of eight samples are illustrated. The relative standard deviations are less than 5%.
As compared with usual method, the limit of instrument detecting active groups of the poly (dimethyl siloxanes) has been increased by about 1000 times and sampling time has also been decreased by several hundred times with this method. The disturbance of v₂ frequency is less than 0.5 ppm and the spectra resolutions have been proved.

In this paper, the electron spin resonance spectroscopy was used to investigate the free electrons under different temperature for 2,4-Di[α-(thiocar-boxymethyl) ethyl] deuteroporphyrin Ⅸ and 2,4-Di{α-[3-(4-carboxyl thiazo-lidinyl)] ethyl}-deuteroporphyrin Ⅸ after irradiation with ultraviolet-visible light.
The samples were irradiated in air and in vacuum, the concentration of spin (N) were found to be 10¹⁶-10¹⁷ spin/g.
Also, the Kinetic behaviour under radiation were discussed.

On the hypothesis of infinite length cylindrical medium,demagnetization factor, geometrical factor and susceptibility correction formula for arbitrary angular orientation of NMR sample tube with reference to the magnetic field are derived. It is concluded that under magic angle condition, solution susceptibility effect could be eliminated, which is similar to that of ellipsoid medium sample by Garroway. Exprimental results agree well with the theoretical deduction obtained.

We have used CO laser magnetic resonance method to observe NO₂ molecular magnetic resonance signal. The Specta we got is different with that Freund (1975) got.This paper also gives the experimental apparatus and the experimental results.

It has been known that the most satisfactory method of determining rate constants and activation parameters is a full steady-state line-shape fitting orer the temperature range where exchange effects can be observed. For weakly coupled systems undergoing exchange it is possible to compute theoretical ine shapes using modified Bloch equation, but strongly coupled systems require a full density matrix (DM) treatment. The aim of this paper is to show how-to calculate line-shapes using the DM method. The paper consists of the basic theory of DM and the applications of DM theory to NMR line-shape calculations of inter-and intra-molecular exchanging systems.

Time domain ESR is an indispensable technique for the study of paramagnetic relaxation mechanism and the dynamic processes, it is also an important way for enhencement of sensitivity and resolution of spectra. But the frequency domain is still used widely in ESR technique, and the time domain ESR (including FT) is not well developed as fast as FT-NMR now. It is discussed in this paper, and we conclude that time domain ESR would be developed quickly by the application of a slightly different way from PFT-NMR under the improvement of microwave technology, fast pulse circuits and computer techniques.
More recently, saturation recorery and electron spin echo (ESE) are the most attractive methods in time domain ESR. Their basic principles, experimental methods, applications, advantages and limitations are emphatically reviewed in this article. For instance in order to obtain high resolution spectra,the envelope of ESE modulation is transformed to frequency domain by FT (including two dimensional FT), so the weak hyperfine structure of oriented or randomly oriented samples may be analysed. Other example as the ENDOR-ESE has better sensitivity and lower detectable ENDOR frequency over conventional ENDOR.
Furthermore, time-resolved ESR of transient paramagnetic intermediates and transient ESR of molecular triplet state in zero field are also discussed in short. The further development of time domain ESR is expected at last.