Structures and Reactivity of Oxygen‐Rich Scandium Cluster Anions ScO3–5−

Oxygen‐rich scandium cluster anions ScO_3–5^? are prepared by laser ablation and allowed to react with n‐butane in a fast‐flow reactor. A time‐of‐flight mass spectrometer is used to detect the cluster distribution before and after the reactions. The ScO₃^? and ScO₄^? clusters can react with n‐butane to produce ScO₃H^?, ScO₃H₂^?, and ScO₄H^?, while the more oxygen‐rich cluster ScO₅^? is inert. The experiment suggests that unreactive cluster isomers of ScO₃^? and ScO₄^? are also present in the cluster source. Density functional theory and ab initio methods are used to calculate the structures and reaction mechanisms of the clusters. The theoretical results indicate that the unreactive and reactive cluster isomers of ScO_3,4^? contain peroxides (O₂^2?) and oxygen‐centered radicals (O^.?), respectively. The mechanisms and energetics for conversion of unreactive O₂^2? to reactive O^.? species are also theoretically studied.     

双层包裹聚磷酸铵微胶囊合成及其在环氧树脂中阻燃研究

采用原位聚合法制备了蜜胺树脂(MF)和环氧树脂(EP)双层包裹聚磷酸铵(APP),得到一种新型核壳结构的微胶囊阻燃剂(EMFAPP).用傅里叶红外光谱(FTIR)和扫描电镜(SEM)对微胶囊的核壳结构进行了表征;用极限氧指数(LOI)、垂直燃烧等级测试(UL 94)对EMFAPP在EP中的阻燃性能进行了研究.EMFAPP在EP基体中阻燃性能优异,当其添加量大于7%时EP/EMFAPP均通过UL 94 V-0级,LOI值达27.0%以上.与未包裹APP相比,EMFAPP耐水性明显提高;经水处理(75℃,6天)后,EMFAPP/EP仍可保持良好的阻燃性能.采用热重分析对EMFAPP及其阻燃复合物的热降解行为进行了研究,EMFAPP能够促进成炭,EP/EMFAPP(8 wt%)在700℃残炭率达16.2%,但其低温稳定性有所下降.此外,利用热失重-红外联用对EMFAPP/EP的热降解行为进行了研究,探讨相关阻燃机理.     

不同囊材聚磷酸铵微胶囊在环氧树脂中的阻燃研究

采用原位聚合法合成制备了以蜜胺树脂(MF)、环氧树脂(EP)以及EP和MF为囊材的微胶囊阻燃剂MFAPP、EPAPP、EMFAPP,用红外光谱(FT-IR)和扫描电镜(SEM)表征微胶囊阻燃剂的核壳结构。采用极限氧指数(LOI)和垂直燃烧等级测试(UL94)对MFAPP、EPAPP、EMFAPP在环氧树脂中的阻燃特性进行了研究。当添加量大于7%时,阻燃复合材料均能通过UL 94 V-0级测试,极限氧指数大于27.0%,表明MFAPP、EPAPP、EMFAPP均为EP的高效阻燃剂,这些阻燃剂在EP阻燃过程中均形成了膨胀炭层,属于膨胀阻燃机理。另外在耐水性实验中发现,添加EPAPP、EMFAPP的EP复合材料具有更好的耐水性,经75℃水浸泡6天后,阻燃性能得到了较好的保持。     

高聚合度Ⅱ-型聚磷酸铵的合成

用聚合反应-热处理两段工艺合成了高聚合度的聚磷酸铵（APP）阻燃材料,其结构经XRD,粒度及平均聚合度表征。优化反应条件为：磷酸氢二铵1mol,n（磷酸氢二铵）：n（五氧化二磷）：n（脲）：1．0：1．0：0．3．干燥氨气氛下于290℃反应30min,再经250℃-280℃后处理100min-110min。APP的平均聚合度大于150,粒度小于50μm。     

氧化铜和聚磷酸铵对聚酰胺6热降解行为的影响

氧化铜和聚磷酸铵对聚酰胺6热降解行为的影响     

[Sc(NO_3)_3(H_2O)_2]·(B15C5)的合成、性质和结构

在乙腈介质中培养出硝酸钪和苯并-15-冠-5形成的配合物单晶[Sc(NO_3),(H_2O)_2)。(B15C5),对其进行了熔点、元素分析、红外光谱、摩尔电导等方面的鉴定。X射线结构分析表明,该晶体属单斜晶系,空间群为P2_(1/n),晶胞参数为:α=9.405(6),b=15.569(8),c=15.896(2),β=95.92(1)°,V=2315.5~3,,Z=4,D_c=1.53g/cm~3,D_0=1.54g/cm~3。Sc(Ⅲ)离子同三个双齿硝酸根和两个水分子配位,构成八配位的配合物,并通过氢键与冠醚形成分子缔合物。     

Enantioselective Michael additions of β-keto esters to α,β-unsaturated carbonyl compounds catalyzed by a chiral biquinoline N,N′-dioxide-scandium trifluoromethanesulfonate complex

A catalytic, enantioselective Michael addition of β-keto esters to α,β-unsaturated carbonyl compounds was achieved by using a chiral biquinoline N,N′-dioxide-scandium trifluoromethanesulfonate complex as a catalyst. The corresponding Michael adducts were obtained in high yields and with enantioselectivities up to 84% ee.     

二溴水杨醛异烟酰腙的合成及其与钪的荧光反应研究

合成了新荧光试剂３，５－二溴水杨醛异烟酰腙（简称ＤＢＳＩＮ），研究了该试剂与钪的荧光反应，在ｐＨ４．７～５．５乙醇／水溶液中，试剂与钪所形成的荧光络合物的λｅｘ＝３３５．４ ｎｍ、λｅｍ＝５１０ｎｍ．提出了混合稀土氧化物中微量钪的测定法。