The π(△M_J=0) transitions of moleculcs NO and NO₂ in the DC discharge are measurcd by the lascr magnctic resonance; The relation between the NO_x coneentration and the discharge paramcters has been studied. The expcrimental results are analysed.

The ligand-exchange equilibria that are establishcd in Al(Ttfac)₃-acac and Al(Ttfac)₃ systems,where Ttfac=Theonyltrifluoroaeetone,acac=aeetylaeetonate,have been studied by means of ¹⁹F NMR spcctroscopy. For Al(Ttfac)₃-acac system,it is found that the distribution of complexes in mixtures accords with the statistical be-havior, For Al(Ttfac)₃-Al(acac)₃ systcm, the ligand-exchange equlibria may be des-cribed in terms of three indcpendent cqulibria.Equlilbrium constants have been deter-mined in chloroform solution, The relationship between the structure of complexes and energy is discussed in this paper.

Triptonide has been isolated from root of the medicinal plant Tripterygium wilforidii.Analysls of ¹H and ¹³C NMR spectra of(I),with the aid of COSY and HCCOSY and COLOC experiments,has allowed unambiguous chemical shift assignments of all protons and carbons of this compound.

The ¹H-¹H COSY,¹³C-¹H COSY and COLOC spectra as well as UV,HREIMS were used to establish the structurc of qianhucoumarin F isolatcd from the root of Peucedanum praeruptorum Dunn,which is a kind of traditional Chincse medicines.The study of 2D NMR shows that qianhucoumarin F is an ester of enol,its structure was elucidated as 3'-senccioylxanthyletin.This kind of compounds of esters of enol such as qianhucoumarin F has seldom been found in the nature.

In this paper,a general relationship between the nuclear spin-Spin coupling con-stants(¹J_AB) across one bond and the s-character of hybrid orbitals and atomic net charges of atonis A and B is foimulated. The relationship obtained is applied to calcu-lation of the α-C-H coupling constants:¹J_CH for a series of substituted hydrocarbons by use of the CNDO/2 molecular orbital approximation and natural hybrid orbital scheme.It is verified that the J_CH values are crudely correlated with carbon hybridiZation and bond polarity.The latter becomes important for α-C-H coupling constants for liydrocarbons containing heteroatoms or substituents.Some discussions concerning the ealculatcd results and the factors which affect the coupling constants are also reported.

Metabolism of mice was studied by in vivo ³¹P NMR spectroscopy.spectra of brain,leg muscle and liver were obtained, using a two-turn surface coil.Peaks of PCr, ATP,PME PDE and Pi were observed and their Chemical shifts determined,The pH value of brain is 7.15, according to the chemical shift of Pi.The contaminated spectrum of liver was corrected by subtraction of a muscle spectrum from the observed spectrum.Metabolism of mice brain in hypoxia was studied.The pH value of brain decreased from 7.1 6 to 6.46 when mice died at the end of experiment.

The internal motions of β-Elemene, which is anti-cancer compound, have been investigated by using variable temperature ¹³C NMR relaxation experiments for the rirst time.The results show that the hexacyclic ring in β-Elemene is almost rigid in experimental temperature range from 298K to 318K and the self-diffusion activation energy of overall motion of the molecule is 14 kJ/mol. All the intenal rotation activation energies for side Chain molccular groups CH₂=CCH₃-and CH₂=CH-connecting with the hexacyclic ring are 19 kJ/mol.The methyl group linking directly the hcxacyclic ring has much higher internal rotation activation energy,which is 18 kJ/mol, than those in two side chain groups CH₂=CCH₃-which connect with the hexacyclic ring at different positions and moreover, the methyl groups in the two side chain groups CH₂=CCH₃-have different internal rotation activation energies which are 7,7 kJ/mol and 2.8 kJ/mol, respectively; This may result from that the three methyl groups have different space circumstances in β-Elemene.

Four mononuclear cobalt compounds Co(mpo)₃·MeCN(I),Co (mpo)₂ PBu₃(Ⅱ),Co(mpo)₂Py(Ⅲ),Co(mpo)₂Py₂(Ⅳ) were studied by ¹H NMR, Their magnctic, electronic and molecular structures were discussed. The results indicate that compound(Ⅱ) was dissociated easyly Co (mpo)₂ and PBu₃ in dimethylsulfoxide solution while others are stable as the molecular structure remains the same as in solid state.

A new formalism was proposed to describe the evolution of density operators in multi-pulse NMR experiments for the strongly coupled AB spin systems(I=1/2); The evolution formula of spin operators were derived.The polarization transform INEPT experiment and two-dimensional DQ-INADEQUATE experiment were deseribed. The formalism is distinct on physical meaning and requires less ealculation.

In this paper the ¹H NMR data of 1,2-disubstituted,1,3-disubstituted and 1,2,3,-trisubstituted tetrahydro-β-carbolines are reported,the relationships be-tween the chemical shifts of 1-H and the configurations of 1-C are discussed, and based on the NOE effects the conformation of compounds (1S, 3S) 3 and (1R, 3S) 3 under the experimental conditions were analysed.

The ESR spectra of magnanese sulfonated cthylene-propylene-diene terpolymer (SEPDM-Mn) in mixed solvent of xylene and alcohol have been investigated.The spectra exhibit resolved six hyperfine lines or a single broad line depending upon the solvation extent between Mn²⁺ and alcohol. The aggregation state of Mn²⁺ is affected by the coneentration of Mn²⁺, alcohol content in the mixed solvent,molecular volume of alcohol and temperature. All these results are consistent with those obtained from the viscometric behaviors of ionomer solutions

Some synthetic flavones, flavanones and chalkones were studied by ¹H NMR.The spectral characteristics,regularitied and effect of substituting groups on the chemicalshifts are reported.

By using the method of CO₂ intracavity laser magnetic resonance(LMR),the σ (△M_J=±1) transitions of v₂ band of NO₂ have been detected.About 100 zeeman com-ponents in 22 laser lines were detected.

A fast two-dimensional (2D) NMR data processing software (PC NMRⅡ) that runs on general personal computer is developed. The program operates with the user-friendly interface in the common routine as the commercial NM R spectrometers for 2D NMR data processing and display. The processing results are available to the other PC-based NMR application programs also.The essential features of this program are described.

The theory of paramctric spectral analysis and its use in NMR data processing field was presented.Then,an efficient method for parameter computing,called High-order Yule-Walker Equations (HOYWE) method was introduced. This is a high precision method for computing the coefficients of the AR part of an ARMA model,therefore the resulting spectrum is very similar to the corresponding true spectrum,In order to facilitate the using of this new method, a simple but effective strategy for choosing the true number of complex exponential components in signal was proposed. The computer simulation tests have justified the applicability of this strategy and the HOYWE method.