Crystal structures of the titled complexes have been determined by X-ray diffraction technique.Nd-Al and Y-Al complexes are isomorphous and both have two Al and two rare earth ions as coordination metals with a center symmetry.Each Ln is coordinated by 6 TFAG and two THF molecules forming a distorted tricapped triprismatic polyhedron and each Al is coordinated by two i-Bu and two TFAG forming a tetrahedron.It is found that TFAG has three linking types:(A) the two oxygen atoms in one of the three TFAG link with a Nd ion.(B) the two oxygen atoms in the second TFAG separately link with a Nd and an Al atom.(C) one of the two oxygen atoms in another TFAG bidentately coordinated to two Nd ions and another oxygen separately coordinates to Al and one of the two Nd ions.In the case of (C) the carbon atom attached at two oxygen atoms has a SP³ orbital configuration,rather than a SP² type due to hydrogen addition.1D and 2D NMR results demonstrated the existence of such a TFAG disproportionate ligand.It is also found that the coordination structure in solution keeps invariant as it is in the solid state.The NMR spectra indicate the presence of two i-Bu conformations under slow exchange in THF solution.

In this paper,kinetic behavior of the group transfer polymerization of ethyl acrylate initiated directly with triphenyl-phosphine and trimethylchlor-silane was studied by means of ³¹P NMR and ¹H NMR kinetic spectra.Elementary reaction of initiating step,chain adding step and chain stopping of this GTP reaction was investigated.Kinetic behavior of conjuated addition of TPP to EA and catalytic action of zinc bromide in this initiation system were discussed.GTP reaction process history in this new initiating system was also proposed.

Electron spin resonanoe (ESR) has been applied to direct measurement of free radical generation in ischemic perfused rat myocardium at 110K.The results show that the isolated perfused rat heart subjected to 30-minute ischemic followed by 15-second reperfusion induced a significant increase of oxygen free radicals production.It was found that the active oxygen free radicals were about 188% more in ischemic reperfused than those in normal perfused.After pretreatment of the heart with GTP,the oxygen free radicals can be reduced by 71%.These results might indicate that the natural antioxidants GTP can protect the heart from the injuries by ischemic reperfusion.

ESR spectra of VO²⁺-Glu-phen and VO²⁺-Glu-bipy ternary systems in glycol-water (1:1) solution at various acidity have been observed at low temperature (173K).It has been found that in different pH ranges the complexes with different structures were formed.According to Johnsons rule and IR data,their possible structures are suggested.Using electronic spectral data,the crystal field parameters were calculated.

The effects of rare earth ions (Y³⁺,La³⁺ and Lu³⁺) on the dynamic structure of HSA were studied by ²³Na NMR spectroscopy.The protein would be expanded and the mobilities of the molecular backbone would be enlarged by binding the rare earth ions,which would lead to the decrease of the correlation time (τ_c).There are three or more highly rare earth binding sites on HSA.The dynamic structural change is revelsible to some degrees,that is,the original state would be recovered if the highly binding rare earth ions were removed by chelating agents.

A new method is proposed for the determination of the complete 2D NOESY mixing coefficient matrix from the peak intensities of nonsymmetric 2D NOESY in which its overlapping peak intensities are included.The method was confirmed with numerical simulated studies.The method makes full use of the nonsymmetric 2D NOESY overlapping peak intensities in calculating the full 2D NOESY mixing coefficient matrix.This may benefit the accurate measurement of internuclear distances in such complex spin systems as biomacromolecules.

Ploy-substituted benzene can be simply synthesized via acyclic precursor through intramolecular witting reaction.But the relative situation between each o f the substituents can not be easily confirmed by the empirical calculation of chemical shift of aromatic carbon through normal 1D NMR experiments.
2D COLOC NMR technique is an efficient method to determine the location of each substituent of poly-substituted benzene,This paper deals with the application of COLOC to the structural identification.The difference between the calculated and the measured chemical shift of each aromatic carbon and the ³J_CF coupling constants were discussed.

The ligand-exchange equilibria that are established in Al (Ttfac) ₃-Al (bzac) ₃ system,where Ttfac=Theonyltrifluoroacctone,bzac=benzoylacetone,have been studied by means of ¹⁹F NMR spectroscopy.The ligand-exchange equilibria may be described in terms of two independent cquilibria.Equilibrium constants for formation of each mixed-ligand complexes from the parent complexes have been determined.It is found that the mixed complexes are favored at the expense of parent complexes.Deviations from a statistical distribution of ligand are relatcd to geometric isomers in complexes.

³¹P NMR chemical shifts for all classes of 106 acyclic tetracoordinate organophosphorus esters have been calculated in this paper by an unified equation.The results showed that the unified equation has wider application than other formula of calculating chemical shifts.The spherical symmetry of the electron cloud around the nucleus is a primary factor affecting ³¹P NMR chemical shifts.

Structural changes of polyacrylonitrile (PAN) in pyrolysis have been studied by using ESR and solid state ¹³C NMR.The line shape and g-factor remained constant over the whole temperature range (250-600℃).The ESR line widths,ΔH_PP decrease with temperature.The spin concentration increased with the increase of temperature in the first stage and then decreased with further increase of temperature.Great change of ¹³C NMR spectra had been found in the process.All the results show that complicated fused conjugated ring systems are formed in the pyrolysis.

H-type cross-links produced by photoinitiated cross一linking of n-C₂₄H₅₀ as a model compound of polyethylene in the presence of benzophenone as photoinitiator have been studied for the first time by solution-state ¹³C NMR spectroscopy.Resonance lines assigned to the CH,α-CH₂,and β-CH₂ carbons associated with H-type cross-links have been observed and identified for the photocross-linked samples,and compared with data from the model compound and γ-irradiation cross-linking of n-paraffins and polyethylene.A new resonance line at 40.83 ppm is attributed to methine carbons in H-links.The other two new resonances at 31.57 ppm and 28.37 ppm are assigned to α-CH₂ and β-CH₂,respectively.The quantitative studies in this work show that the number of H-links is estimated to be 8.5-11.0 per 10000 carbon atoms for samples UV-irradiated in vacuum in the melt for 3-5min.

An unknown white solid compound is very soluble in water.Its single crystal is not obtained now.The NMR technique plays an important role in determining its structure.From the routine ¹H NMR spectrum (Fig.1),¹³C NMR spectrum,decoupling without NOE ¹³C NMR spectrum,off-resonace ¹³C NMR spectrum,(Fig.3),¹H-¹H COSY spectrum (Fig.2),and ¹³C-¹H correlated 2D spectrum (Fig.4),it proves that there are an alkylchain X-CH₂-CH₂-CH₂-Y and an aromatic group Y in this compound.¹³C-¹H correlated spectrum via long range couplings (in inverse probe)(Fig.5) may determine how to connect between the chain and the group.So its main skeletal must be X-CH₂-CH₂-CH₂-Y.IR spectrum (Fig.6),shows us theexistance of the-SO₃-group.From the results of element analysis and MS spectrum,including FAB-MS spectrum (Fig.7 and 8),It was finally judged that the molecular structure of this compound should be the internal salt of pyridinium-N-propane-sulfonic acid.Its structural formula is .

Using the method of CO intracavity laser magnetic resonance (LMR),we have detected the π(ΔM_J=0) transitions of ν₂ band of free radical NH₂.About 13 Zeeman components in 3 laser lines were detected,among them 3 Zeeman components in 1 laser line agree with the previous reported and 10 Zeeman components in 2 laser lines haven't been reported previously.

In this paper,the ESR spectra of American ginseng radiated by ⁶⁰Co have been observed for long time.The result shows,two or more than two kinds of instable free radical and a stable free radical produced in American ginseng,when the radiation dose is beyond 12 kGy.Which indicates permanence radiation damage of American ginseng.The decay constants of instable free radical in American ginseng were measured.

The structure and component of an unknown mixture need to be investigated before production.The qualitative and quantitative analysis of an unknown mixture were done normally by GC,HPLC,UV,MS,IR and chemical isolation method.In this work,¹³C NMR has been used in determining the structure and component of the unknown mixture with microcomputer searching sadtler data base easily.The chemical names are SUCCINIC ACID,DIMETHYL ESTER,GLUTARIC ACID,DIMETHYL ESTER,ADIPIC ACID,DIMETHYL ESTER,and their content percentages are 22.5%,62.5%,15.0% respectively.The obtained results are in agreement with those of GC-IR method.

In this paper,pulsed field gradients are used to suppress the rapid-pulsing artifacts.Due to its superior homospoil charactersitic,pulsed field gradients offer an important method for removal of artifacts when data is being acquired fast compared to the relaxation times of the nuclei under study.The experimential results show that the quality of DQF-COSY spectra can be improved by the modified pulsc sequence,and the pulsed field gradients provide a good method for ultra-rapid acquisition 2D COSY-like NMR experiments with suppression the repetition rate artifacts.