甲乙酮肟封闭聚氨酯预聚体的研究

首先用聚己二酸-1,4-丁二醇酯二醇和甲苯二异氰酸酯(TDI)制备端异氰酸酯预聚体,然后用甲乙酮肟封闭预聚体的异氰酸酯基团。用化学分析方法研究了封闭反应温度、反应时间以及物料的配比对异氰酸酯基团封闭率的影响,用红外光谱仪研究了封闭前、封闭后和加热解封后的预聚体异氰酸酯基团特征吸收峰的变化。实验结果表明:随反应温度的升高、反应时间的增加或N(活泼-H)/N(-NCO)增加,异氰酸酯基团封闭率增大;在80℃,N(活泼-H)/N(-NCO)=1.2,反应4 h的条件下,甲乙酮肟可完全封闭异氰酸酯基团;甲乙酮肟封闭的聚氨酯预聚体能在135℃下解封。     

纳米钛硅分子筛TS-1催化甲乙酮氨氧化合成甲乙酮肟

以纳米钛硅分子筛TS-1为催化剂，采用三口玻璃反应器研究了甲乙酮（MEK）氨氧化的反应性能。采用SEM、TEM和XRD等分析手段表征了TS-1的晶粒尺寸。考察了TS-1的晶粒尺寸、反应物的加料方式、溶剂、催化剂用量、反应温度和反应物料配比对甲乙酮氨氧化反应性能的影响。结果表明，甲乙酮氨氧化反应的最佳反应条件为：75℃，n（NH3）：n（H2O2）：n（MEK）=4．0：1．5：1．0，TS-1用量21．6g（以1mol MEK计）；H2O2和氨水连续进料，最佳溶剂为叔丁醇或叔丁醇和水的混和液。在最佳反应条件下，甲乙酮的转化率和甲乙酮肟的选择性可分别达到99．4％和99．8％。     

α-吡啶基镧系有机金属配合物的合成及表征

以二茂基一氯稀土化合物Ｃｐ２ＬｎＣｌ（Ｌｎ＝ Ｙｂ，Ｈｏ，Ｄｙ，Ｔｂ，Ｓｍ ；Ｃｐ＝ η５－Ｃ５Ｈ５ ）和等摩尔的α－吡啶锂盐（Ｐｙ－Ｌｉ）反应，合成了一系列未见报道的含Ｌｎ－Ｃσ键的吡啶基镧系有机金属配合物Ｃｐ２ Ｌｎ·Ｐｙ，并通过元素分析、红外光谱和质谱对所合成的化合物进行了表征。根据已有数据推测出这类配合物的分子结构为吡啶的α－Ｃ与Ｌｎ形成Ｌｎ－Ｃσ键，吡啶环上氮原子又以其孤对电子与Ｌｎ 形成Ｌｎ－Ｎ 内配位键。     

Cobalt(II) and nickel(II) complexes bearing mono(imino)pyridyl and bis(imino)pyridyl ligands: preparation,structure and ethylene polymerization/oligomerization behaviors

BACKGROUND: Ethylene oligomerization is the major industrial process to produce linear α‐olefins. Recently much work has been devoted to late transition metal catalysts used in this process, especially those with 2,6‐bis(imino)pyridyl dihalide ligands. Considering that most work has focused on simple modification to the substituents in imino‐aryl rings based on the symmetric bis(imino)pyridyl framework, here we expand this work to the asymmetric mono(imino)pyridyl ligands. RESULTS: The preparation, structure and ethylene polymerization/oligomerization behavior of series of mono(imino) pyridyl–MCl₂ and bis(imino)pyridyl–MX_n complexes are presented. The systematic studies were focused on the relationship between the catalytic behavior of these complexes for ethylene polymerization/oligomerization and reaction conditions, ligand structures, metal centers and counter‐anions. The influence of the coordination environment on catalyst behavior is also discussed. CONCLUSION: For mono(imino)pyridyl–Co(II) and ? Ni(II) catalysts bearing the Cl^? counter‐anion, good activities ranging from 0.513 × 10⁵ to 1.58 × 10⁵ g polyethylene (mol metal)^?1 h^?1 atm^?1 are afforded, and the most active catalysts are those with methyl in both ortho‐ and para‐positions of the imine N‐aryl ring. For bis(imino)pyridyl–Co(II) and ? Ni(II) catalysts bearing the SO₄^2? and NO₃^? counter‐anions, the low activities for ethylene oligomerization are in sharp contrast to those of their chloride analogues. Copyright © 2009 Society of Chemical Industry     

过硫酸钾条件下的脱肟反应

酮肟与过硫酸钾在乙腈和水的混合溶剂中加热回流4h,可方便地得到相应的羰基化合物,条件温和,操作简单,产率高,从而为羰基脱除肟官能团保护提供了一种有效的新方法。     

Preparation and the catalytic activity of novel Pd nanocluster catalysts utilizing an oligosilsesquioxane ligand

Palladium acetate together with a newly synthesized silsesquioxane- pyridyl ligand showed excellent catalytic activity towards the aerobic oxidation of benzyl alcohol to benzaldehyde. TEM measurements revealed the in situ formation of Pd nanoclusters during the reaction period.     

Ammoximation of methyl ethyl ketone with H2O2 and ammonia over TS‐1

The ammoximation of methyl ethyl ketone and hydrogen peroxide to form methyl ethyl ketoxime was studied over zeolites (TS‐1) in the temperature range 308–373 K. The reaction was carried out in a batch autoclave at autogenous pressure. The conversion of methyl ethyl ketone and the selectivity to methyl ethyl ketoxime can reach 99% and approximately 100%, respectively, and the by‐products were the small amounts of corresponding methyl ethyl ketazine and trace amounts of unidentified compounds. Important factors were the reaction temperature, solvents and slow addition of hydrogen peroxide. The molar ratio of NH₃ to ketone had no significant effect on the conversion of methyl ethyl ketone, but increase in the ratio of NH₃ to ketone had a beneficial effect on selectivity. Copyright © 2006 Society of Chemical Industry     

离子选择电极法测定有机分析试剂的纯度

利用金属离子与配位体形成ｎ：１配合物,以金属离子选择电极为指示电极,饱和甘汞电极为参比电极,通过直接测定游离金属离子的活度,建立了测定有机分析试剂纯度的新方法。方法简便可靠,用于２－「（５－溴－２－吡啶）偶氮」－５－苯酚和铬天青Ｓ纯度的测定,获得了满意的结果。     

Noble metal ion sorption by pyridyl and bipyridyl group‐containing chelating polymers

A series of eighteen 4‐vinylpyridine and 4‐methyl‐4′‐vinylbipyridine copolymers with different crosslinkers was examined as sorbents for the noble metal ions of Ag(I), Au(III), Pd(II), and Pt(II) from aqueous solutions. The chelating polymers possess appreciable sorption selectivity for Au(III) over Ag(I) and for Pd(II) over Pt(II). Binding abilities of the copolymers toward the noble metal ions vary as the identity of the chelating heterocyclic amine moiety and the structure of the crosslinkers are altered. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 207–213, 2001     

Ce4+的掺杂和染料结构对TiO2光催化性能的影响

采用浸渍法制备了掺杂Ce^4 的TiO2粉体光催化剂,考察了Ce^4 的含量对TiO2光催化性能的影响,并且研究了它对直接耐晒蓝和4,2-(吡啶偶氮)-间笨二酚钠两种染料的降解效果。结果表明,以TiO2干凝胶为母体,浸渍Ce^4 所制备的粉体光催化剂Ce^4 /TiO2降解效果分别比纯TiO2高45％和23％其对偶氮基团的分解效果明显高于对吡啶环和间苯二酚基的分解。X射线衍射分析表明,该法制备的TiO2粉体中锐钛矿相占90％以上,没有铈的氧化物形式,平均晶粒粒径为1nm;红外吸收光谱分析表明,Ce^4 ／TiO2和TiO2红外吸收光谱图相似,说明掺杂Ce^4 并没有极大地改变TiO2的化学结构。