硅藻土表面酸性质的研究

研究了几种硅藻土的表面羟基结构、表面酸性质及其孔结构，发现除浙江白土表面具有双生的硅羟基外，其他只有连生与孤立的硅羟基；硅藻土中均存在少量的Ｂ酸和Ｌ酸；硅藻土酸性质及经ＮＨ４Ｃｌ或ＨＣｌ活化后的酸性质变化与硅藻土孔结构、表面结构有关。焙烧温度升高，硅藻土酸强度增加，酸量减少。     

双核、三核钼硫原子簇状化合物的合成、反应和性质研究

本文提出了合成双核钼硫原子簇状化合物{[(n—Bu)_4N]_2[(S_2)OMo(μ—S)_2MoO(S_2)]和[(n—Bu)_4N]_2[(S_2)OMo(μ—S)_2MoS(S_2)]}以及三核钼硫原子簇状化合物(Ph_4P)_2[S_2Mo(μ—S)_2SMo(μ—S)_2MoS_2)的新方法,并进行了化学分析和红外光谱,电子光谱的测定。     

硅酸及其盐的研究 ⅩⅪ.三甲基硅烷化-气相色谱法测定单硅酸的离解常数

由于硅酸的聚合性质,单硅酸易发生聚合,溶液中硅酸总量不能代表单硅酸的含量,因而其离解常数不易测准,各家所得数据不一.本文用三甲基硅烷化-气相色谱法测得硅酸溶液中单硅酸含量以求得不同时间下单硅酸的最快聚合点的pH,并以时间外推法求得单硅酸的标准离解常数.本文还用离子强度外推法,求得了单硅酸热力学离解常数。这些常数和公认值一致.     

硅酸及其盐的研究 ⅩⅪ. 三甲基硅烷化-气相色谱法测定单硅酸的离解常数

由于硅酸的聚合性质,单硅酸易发生聚合,溶液中硅酸总量不能代表单硅酸的含量,因而其离解常数不易测准,各家所得数据不一.本文用三甲基硅烷化-气相色谱法测得硅酸溶液中单硅酸含量以求得不同时间下单硅酸的最快聚合点的pH,并以时间外推法求得单硅酸的标准离解常数.本文还用离子强度外推法,求得了单硅酸热力学离解常数.这些常数和公认值一致.     

1,1-双取代二茂铁化合物的13C核磁共振研究

Two 1,1'-disubstituted ferrocene organometallic compounds 1,1'-dihydroxy-methylferrocene (Ⅰ) and 1,1'-diformylferrocene (Ⅱ) have been synthesised. The ~(13)C NMR spectra in CDCl_3 solution have been determined and assigned. A theoritical calculation of ~(13)C NMR chemical shift based on our INDO/σ program has been applied to these two compounds which included d orbitals. These are the most complicated compounds up to now for the chemical shift calculation, It is satisfied for the trend between the theoritical calculation and experiment.     

固相配位化学反应研究——ⅩⅩⅩⅡ.镍钨硫簇合物的固相合成

本文首次成功地在低热温度下固相反应合成镍钨硫杂核金属簇合物:[(n-Bu)₄N]₂[Ni(WS₄)₂]和[(n-Bu)₄N]₂[Ni(WOS₄)₂].用EXAFS、IR、UV.元素分析、TG-DTA等手段对上述化合物进行了表征.研究了温度、气氛等条件对合成反应的影响.     

包括d轨道的NMR化学位移的INDO/GIAO微扰理论

本文推广了计算~(18)C化学位移的INDO/GIAO方法,以进行~(15)N、~(17)O以及过渡元素配合物的~(18)C化学位移计算。通过N,O及Fe的INDO参数的优化选择,计算的~(15)N、~(17)O以及配合物(C_5H_5)Fe(CO)_2CN,(C_5H_4)_2Fe(COH)_2及(C_5H_4)_2Fe(CH_2OH)_2的~(18)C化学位移符合实验结果,同时发现计算的原子净电荷ρ(M)和σ~d(M)之间存在良好的线性关系。     

固相配位化学反应研究——ⅩⅩⅡ.草酸铁与金属氯化物的固相反应

采用气相色谱法,配合穆斯堡尔谱等其他手段研究了草酸铁与金属氯化物在氢气氛和氦气氛中的固相反应。实验结果表明,草酸高铁与氯化铜在180℃时发生氧化还原反应,与氯化亚锡在室温下发生固相还原反应,与碱金属氯化物不反应,但氯离子的存在明显提高了α—草酸亚铁的热稳定性且与氯化物中金属阳离子的价态有关,价态越高,作用越明显。     

Simultaneous chemical fingerprint and quantitative analysis of Ginkgo biloba extract by HPLC–DAD

A reverse-phase liquid chromatography method with diode array detection was developed to evaluate the quality of Ginkgo biloba extract through establishing chromatographic fingerprint and simultaneous determination of eight flavonoid compounds, namely rutin, myricetin, quercitrin, quercetin, luteolin, kaempferol, apigenin, and isorhamnetin. The chromatographic separation was performed on an Agilent SB-C18 column (250 × 4.6 mm, 5.0 μm) with a gradient elution program using a mixture of methanol and 0.1% formic acid (v/v) as mobile phase within 55 min at 360-nm wavelength. The correlation coefficients of similarity for different batches of G. biloba extract from the same manufacturer and G. biloba extract from different manufacturers were determined from the LC fingerprints, and they shared a close similarity. The eight flavonoid compounds showed good regression (R ² > 0.9995) within test ranges, and the recovery of the method was in the range of 94.1–101.4%. In addition, the content of those eight flavonoid compounds in G. biloba extract prepared by different manufacturers of China was determined to establish the effectiveness of the method. The results indicated that the developed method by having a combination of chromatographic fingerprint and quantification analysis could be readily utilized as a quality control method for G. biloba extract and its related traditional Chinese medicinal preparations.