Pyridine -insoluble、THF-insoluble solids of bydrocrachng products of vitrain pyridine-insoluble solid and itself were investigated by solid state ¹³C CP/MAS NMR technique.From the measurements, twelve structural parameters of carbon skeleton were obtained Benzene-soluble subfraction of hydrocracking products were investigated by one and two dimensions ¹H and ¹³C liquid NMR techniques.Their ¹H and ¹³C spectra were assigned.The avcrage molecular structures of these fractionswere obtained.

The plasma treatment of polyvhylidene fluoride (PVF₂)films was carried out in a capacitively coupled reactor with external electrodes.The gel content of PVF₂ treated in various conditions,their shear strength and the contact angle of water on the surface of PVF₂ were mcasured.ESR investigation of the free radicals produced in the process of plasma treatment,indicates that the incrcase of the unsaturated bonds in molecules and highly crosslink reaction were in favour of the adhesion of PVF₂.

Electron-nuclear dipolar interaction and spin-diffusion play very important roles in the relaxation processes of molecules adsorbed on solids containing surface eleetrons, such aS charcoal,alumina and silica gel.According to this relaxation rnechanism,the relation between spin-lattice relaxation time(T_1e)and correlation tim-(τ_c)was obtainted:T_1e,-k(τ_c/1+ω₀²τ_c²)^1/2,k is a con-stant for a given solid. It was found that the relaxations of toluene adsorbed on silica gel were interpretted well by this formula, The correlation times at dirrerent temperatures and the activqtion energy(E_a=15.0kJ/mol) of methyl group in toluene adsorbed on silica gel were obtained.The correlation times are in the range of 3.56×10^-9-5.76×10^-8s during 374 K and 240 K.

Radical intermediates generated in photocatalytic oxidation of some organic com-pounds containing nitrogen atoms such as butylamine,piperidine, pyridine etc,were detected by spin trapping technique. The ESR spectra of N-eentered radical adduct and C-centered radical adduct were observed.Experiment results reveal that these radicals are participants in the inital steps of photodegradation of thesc com-pounds,A mechanism which is consistent with the observation of these radical species is elucidated.

Polyetherimide(YS-30)is one of the soluble polyimides. This paper presents the re-sults of our study on its ¹³C NMR,¹H NMR,H-H COSY and C-H COSY spectra. On this basis the assingments of these spectra are very satisfactorily obtamcd.Hence the chain structure of the polymer has been recongnized clearly.

SAPO-5 molecular sicve bas been synthesized by hydrothermal method.Palladium is supported on it by adding Pd salt solution (Pd(NH₃)₄Cl₂ and H₂PdCl₄)into the mixture gel of SAPO-5 before crystallizzation in order to obtain bifunctional catalyst.The result of X-ray diffraction reveals that the introduction of palladium salt in the mixture gel does not deprcss the formation of SAPO-5. However,when palladium is added in the form of Pd(NH₃)₄Cl₂, there intergrows a little SAPO-34 in the product.MAS NMR results show that the addition of palladium obstructs silicon to enter the framework and thus makes a more symmetrical coordination environment of alumini-um and Causes partialy decomposition and polymeriZation of the template in SAPO-5.The reaction of the template during crystallization differs with the palladium precur-sors.³¹P MAS NMR result shows that the addition of palladium salt in the mixture gel has little influence on the coordination environment of phosphorus in the framework.

Two diterpenes were isolated from tripterygium wilfordii Hook.F.The structures were deduced using various 2D NMR techniques (H-H COSY,HETCOR, COLOC).Analysis of ¹H and ¹³C NMR spectra of 1 and 2 has all owed unambiguous chemical shift assignments of all protons and carbons of these compounds.

The influence of paramagnetic ions, Fe³⁺ and Cu²⁺ on relaxation time T₁ of amino acids which are structural units of peptides has been investigated in this paper.The for-mula only for monospecies system of chemical molecule and metal ion has been ex-tended to polyspecies system and the system in which there are chemical exchanges. The linear relations of paramagnctic relaxation rate(R_1p) and concetration of metal ions (C_M) have been elucidated and demonstrated.The relations between the slope of curves and coordinating ability and concentration of ligands have been discussed.

It is proposed that only the heteronuclear cross relaxation rates between ¹³C and ¹H,which are only dependent on the diporlar relaxation,are used to investigate the mo-lecular internal motions,The new method is more reasonable than the conventional one in theory where the nuclear longitudinal relaxation time T₁,transvcrse relaxation T₂ and NOE factor η are used to study the molecular internal motions. The general formu-la separating the contribution of dipolar relaxation to the total ¹³C spin relaxation is set up. It can be applied not only to small molecules inside extreme narrowing condi-tion but also to macromolecules outside extreme narrowing.

Two samples(1^#,2^#)of 3-formhydrazone-rifamycin SV produced by fermentation and chemieal modification have different physical and chemical properties.In this paper,their structures were determined by various kinds of NMR spcctra, such as ¹H,¹³C,DEPT,¹H-¹H COSY,¹H-¹³C COSY and LR ¹H-13 C COSY in inverse mode, and by the absorption spectra of IR and UV-Vis.It was found that the two samples were the main product of amide mode (1^#) and the isomer of iminol mode (2^#). Based on the results of experiments,the isomerization of sample 1^# was discussed.

In the present paper,the dynamic isotope effect of ¹⁴N relaxation of DMF/H₂O(D₂O) system is reportcd.The ¹⁴N rclaxation times of DMF in DMF/H₂O and DMF/D₂O systems have been measured through all composition range (mole fraction of DMF from 0 to 1).The solvent isotope effect on relaxation and the factors affecting the quadrupole relaxation are discussed.The results suggest that in the given system there is a close relationship between the ¹⁴N relaxation and the kinetics of solvent water.Under infinite dilutions,the kinetics of the solute molcculcs are controlled complctely by the solvent molecules.

The Faraday effect was used in laser magnetic resonance for improvement of the signal to noisc ratio,Both theoretical analysis and the experimcntal results are given in this paper.The results show that the signal to noise ratio was improved in more than one order.

The reaction process of Cp₂Zr(H)Cl with RNCS (R=C₆H₅,c-C₆H₁₁,n-C₄H₉) has been detected by ESR method. The ESR results show that in the process the Zr-H bond deaved homolytically and a transient Zr(Ⅲ)species is formed. The reactions oeeurred via a radical mechanism.

In this article three methods(inverse gated dec,J-modulated spin-echo and 2D-J-resolved) for measuring the protonated and non-protonated carbons were dis-cussed and compared. The average molecular parameters of three kinds of polycyclic aromatic hydrocarbons derived from petroleum and coal were independently calculated by three methods,and the structure of three complex mixtures were primarily analysedand discussed.

The main difficulty in 2D NOESY of mcdium-sized peptdes is lacking of cross-peaks, espccially in the region related with NH, For solving this problem, these authors use a mixed solvent,CD₃OD/H₂O, to dissolve peptides,which allows NMR measurements at low temperature.The increased viscosity of solution and the correlation times by low-temperature measurements made a lot of intra-and inter-residue NOES observable, which helped us unambiguously complete the assigmnents of a nonapeptide and an undccapcptide, and further in calculation of H-Hdistances.