The dynamic ~1H and ^(13)C-NMR studies on [Li(2D)][Nd(η~8-C_3H_5)_4] (D=dioxane)were reported The four allyls coordinated to Hd^(8+) ion are equivalent and hydrogens appear as three groups in ~1H-NMR spectra with the...The dynamic ~1H and ^(13)C-NMR studies on [Li(2D)][Nd(η~8-C_3H_5)_4] (D=dioxane)were reported The four allyls coordinated to Hd^(8+) ion are equivalent and hydrogens appear as three groups in ~1H-NMR spectra with their chemical shifts changing with temperature.C_1 and Ca are equivalent showing the characteristic of η~2=-allyl.The paramagnetic shifts of carbons in allyls induced by Nd^(2+) ere separated sucessfully.C_1 and C_3 located on the zero-dipolar cone.The content of contact shift is greater than that of dipolar slift to Co.展开更多
This paper described the ~3H NMR determination of the positions and content of 24 tritium labeled aromatic and heterocyclic compounds prepared by catalytic tritiation derivatives, pyrrole, 1,2,4-triazole, thiazole, be...This paper described the ~3H NMR determination of the positions and content of 24 tritium labeled aromatic and heterocyclic compounds prepared by catalytic tritiation derivatives, pyrrole, 1,2,4-triazole, thiazole, benzothiazole, purine and derivatives, indole, indanol, piperidine and derivative, diphenylamine, N- phenylanthranilic acid, 8- OH- quinoline, naphthol, diphenylether have been tritiated by catalytic exchange method using tritiated water and platinum catalyst (from the dioxide and sodium borohydride), and the pattern of labelling has been assigned by ~3H NMR spectroscopy. The results show that this exchange process can give general labelling compounds at various time and temperatures. For 4-Br-diphenylether, Raney nickel was used instead of Pt as a catalyst.展开更多
The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of...The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of pure (CH_3CH_2)_3N and thiophenol, these values are moved to high position, and the width of these peaks is obviously increased. These characteristics conformed to NMR spectra of paramagnetic compounds and their molecular structures. The paramagnetic property of these compounds was also studied with ESR spectrum. Mass spectra of three compounds were determined. The main fragments were observed, for example, m/z: 130〔(C_2H_5)_4N〕+, 264〔Fe_3S_3〕+, 144〔Fe-S-Fe〕+, 120〔S-Fe-S〕+, 88〔Fe-S〕+, 136〔FeBr〕+, 91〔FeCl〕+ etc. These supported structural characteristics of the anion skeleton and molecules strongly. The possible mechanism of fragmentation was discussed.展开更多
As we know, there are three structures-sⅠ, sⅡ, and sH, with hydrocarbonate gas hydrate.Because of those special structures characteristics and potentail large fossil energy resource, gas hydrate play an important ro...As we know, there are three structures-sⅠ, sⅡ, and sH, with hydrocarbonate gas hydrate.Because of those special structures characteristics and potentail large fossil energy resource, gas hydrate play an important role in natural carbonate cycle system. In this paper, CH4, CO2, C3H8, and CH4 +CO2 system have been experimental performed in order to model hydrate formation and discomposition and to obtain hydrate stability conditions of tempreature and pressure. The results from laboratory using Raman spectra show that Raman spectrascopy is a effective tool to identify hydrate structure. Raman spectra of clathrate hydrate guest molecules are presented for two structure (sⅠ and sⅡ) in the following systems: CH4, CO2, C3 H8. Relatively occupancy of CH4 in the large and small cavities of sⅠ were determined by deconvoluting the v1 symmetric bands, resulting in hydration numbers of 6.04±0.03. The freqyuency of the v1 bands for CH4 in structures Ⅰ and Ⅱ differ statistically. The large cavities were measured to be almost fully occupied by CH4 and CO2, whereas only a small fraction of the small cavities are occupied by CH4. No CO2 was found in the small cavities.展开更多
文摘The dynamic ~1H and ^(13)C-NMR studies on [Li(2D)][Nd(η~8-C_3H_5)_4] (D=dioxane)were reported The four allyls coordinated to Hd^(8+) ion are equivalent and hydrogens appear as three groups in ~1H-NMR spectra with their chemical shifts changing with temperature.C_1 and Ca are equivalent showing the characteristic of η~2=-allyl.The paramagnetic shifts of carbons in allyls induced by Nd^(2+) ere separated sucessfully.C_1 and C_3 located on the zero-dipolar cone.The content of contact shift is greater than that of dipolar slift to Co.
文摘This paper described the ~3H NMR determination of the positions and content of 24 tritium labeled aromatic and heterocyclic compounds prepared by catalytic tritiation derivatives, pyrrole, 1,2,4-triazole, thiazole, benzothiazole, purine and derivatives, indole, indanol, piperidine and derivative, diphenylamine, N- phenylanthranilic acid, 8- OH- quinoline, naphthol, diphenylether have been tritiated by catalytic exchange method using tritiated water and platinum catalyst (from the dioxide and sodium borohydride), and the pattern of labelling has been assigned by ~3H NMR spectroscopy. The results show that this exchange process can give general labelling compounds at various time and temperatures. For 4-Br-diphenylether, Raney nickel was used instead of Pt as a catalyst.
文摘The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of pure (CH_3CH_2)_3N and thiophenol, these values are moved to high position, and the width of these peaks is obviously increased. These characteristics conformed to NMR spectra of paramagnetic compounds and their molecular structures. The paramagnetic property of these compounds was also studied with ESR spectrum. Mass spectra of three compounds were determined. The main fragments were observed, for example, m/z: 130〔(C_2H_5)_4N〕+, 264〔Fe_3S_3〕+, 144〔Fe-S-Fe〕+, 120〔S-Fe-S〕+, 88〔Fe-S〕+, 136〔FeBr〕+, 91〔FeCl〕+ etc. These supported structural characteristics of the anion skeleton and molecules strongly. The possible mechanism of fragmentation was discussed.
基金Supported by the National Natural Science Foundation of China (No. 49973024, 40272066)211 Projects of Xiamen University.
文摘As we know, there are three structures-sⅠ, sⅡ, and sH, with hydrocarbonate gas hydrate.Because of those special structures characteristics and potentail large fossil energy resource, gas hydrate play an important role in natural carbonate cycle system. In this paper, CH4, CO2, C3H8, and CH4 +CO2 system have been experimental performed in order to model hydrate formation and discomposition and to obtain hydrate stability conditions of tempreature and pressure. The results from laboratory using Raman spectra show that Raman spectrascopy is a effective tool to identify hydrate structure. Raman spectra of clathrate hydrate guest molecules are presented for two structure (sⅠ and sⅡ) in the following systems: CH4, CO2, C3 H8. Relatively occupancy of CH4 in the large and small cavities of sⅠ were determined by deconvoluting the v1 symmetric bands, resulting in hydration numbers of 6.04±0.03. The freqyuency of the v1 bands for CH4 in structures Ⅰ and Ⅱ differ statistically. The large cavities were measured to be almost fully occupied by CH4 and CO2, whereas only a small fraction of the small cavities are occupied by CH4. No CO2 was found in the small cavities.
