活性氮与溴分子反应的实验研究

在流动反应管中, 利用高纯N₂空心阴极放电制备活性氮, 研究了活性氮与溴分子碰撞反应得到的发射光谱. 在540～800 nm波段观察到了较强的NBr(b¹Σ^＋→X³Σ^－)跃迁发射谱, 在292 nm处观察到了Br₂(D'→A')辐射跃迁. 实验结果表明, 得到的NBr(b¹Σ^＋)显示出了非弛豫的发射特征, 最高振动能级为ν'＝9. 激发态的NBr(b¹Σ^＋)是由活性氮中的N(²P)原子与Br₂直接反应生成的.     

活性氮反应产生激发态卤化氮实验研究

A new method for producing electronically excited nitrogen monohalides NX(b) (X=F,Cl,Br) is reported. The strong emission spectra of NBr(b1Σ+→X3Σ–) are observed when alkyl bromides (CHBr3, CH2Br2, C2H5Br, and C4H9Br) are added to a stream of active nitrogen, generated by a hollow-cathode discharge of N2, in a flowing afterglow system. Some tentative experiments show that the electronically excited NBr(b) is formed by means of metastable N2(A3Σu+) Electronic-to-Electronic energy transfer to NBr(X), which is from the reaction of N(4S) with alkyl bromides. The emission spectra of NCl(b1Σ+→X3Σ–) are obtained when CCl4 or SOCl2 is admitted into a flow of active nitrogen, but neither CHCl3 nor CH2Cl2 addition results in such an emission. It has been proposed that the origin of the excited NCl(b) is an energy transfer from N2 (A) to NCl(X), generated by the reaction of N(4S) with CCl3 (or SOCl2). Similar experiments are also carried out with SF6 as reagent of active nitrogen, or as mixture with N2 in the discharge. By recording fluorescence it was found that excited NF(b) is produced only under discharge through N2/SF6 mixture. The NF(b) state presumably arises from the energy transfer from N2(A) to NF(X), and the latter is generated from the abstraction of fluorine by N(4S) from SF5.     

活性氮与碘乙烷反应化学发光研究

在流动余辉装置上, 利用N₂空心阴极放电制备活性氮, 研究了活性氮与碘乙烷(C₂H₅I)反应的化学发光. 在620～820 nm波长范围内观察到了较强的发射光谱, 拟合得到的光谱常数表明它来源于NI(b¹Σ^＋→X³Σ^－)跃迁, 并对35个谱峰进行了振动归属. 最后讨论了活性氮中主要成分与C₂H₅I反应的可能过程, 结合辅助性实验分析表明, 活性氮中的N(²P)与C₂H₅I直接反应很可能产生激发态NI(b¹Σ^＋)自由基. 这是利用化学反应直接产生激发态NI(b¹Σ^＋)的首次报道, 观察到的激发态最高振动能级为v'＝6.     

活性钴引起α—溴代酮的反应

近年来,活性钛,活性镍等金属试剂正被用于有机合成并引起人们的关注。最近,对活性钴引起有机反应的研究也日益增多。例如在活性钴试剂作用下,卤代芳烃脱卤偶联得到联苯化合物,α,α—二氯二苯基甲烷脱卤得到四苯乙烯,富马酸与二溴甲烷可以发生不对称环丙烷化反应等。本文报道活性钴试剂引起α—溴代酮的反应。     

铁卟啉与活性氮的相互作用

在活性氮(RNS)与蛋白质的相互作用过程中,含铁卟啉蛋白/铁卟啉可以催化RNS转化为惰性的NO3-,阻止蛋白质的硝化;同时,含铁卟啉蛋白/铁卟啉也可通过高价铁氧化物及.NO2的产生来加速蛋白质的硝化。生理条件下,血红蛋白、肌红蛋白等含铁卟啉蛋白可清除多余的RNS;氧化应激条件下,过氧化物酶等含铁卟啉蛋白可以不同的方式催化加速RNS对蛋白质的硝化。     

活性氮与SO2和SOCl2的传能反应

在流动余辉装置上, 研究了活性氮与SO2和SOCl2之间的反应过程. 在280～500 nm, 观察到了SO2( A1A2,B1B1→X1A1 )和SO2(a3B1→X1A1)的发射光谱. 对比由Ar(3P0,2)与N2碰撞反应产生的纯N2(A3Σu+)与SO2、SOCl2之间反应的实验结果, 可以说明, N2(A3Σu+)在活性氮与SO2的反应中是主要的能量载体, 它与SO2的直接能量转移反应形成了激发态的SO2(A1A2, B1B1); 在活性氮与SOCl2的反应中观测到的激发态SO2(a3B1), 则可能主要是通过N(4S)与SOCl2反应生成的N2O(X1Σ+)和N2(A3Σu+)与SOCl2反应生成的SO(X3Σ－)之间的化学反应过程产生.     

溴代羟基二苯醚的合成及抑菌活性研究

模拟天然溴代羟基二苯醚的结构, 设计并合成了7个溴代羟基二苯醚化合物, 所有这些新化合物的结构均经元素分析, ¹H NMR, MS和IR所证实. 选择8种有害菌对合成的溴代羟基二苯醚进行了抑菌活性检测, 证实它们对所测试菌种具有优良的抑制效果.     

溴代二羟基二苯醚类化合物的合成与抑菌活性研究

设计并合成了7个新的溴代2,2'-, 2,4-'和4,4'-二羟基二苯醚; 所有这些化合物的结构均经¹H NMR, MS, IR和元素分析所证实; 新化合物的结构避免了现有二苯醚杀菌剂在生产和使用过程中有可能生成高毒性二噁类化合物的缺点; 并选择8种有害菌对合成的新的溴代二羟基二苯醚进行了抑菌活性测试, 结果表明它们对所测试菌种具有很好的抑制活性, 与目前国内外广泛使用的广谱抗菌剂三氯新的抑菌活性相当.     

三氮唑类化合物的合成及抗真菌活性研究

近年来深部真菌感染的发病率和病死率逐年增加;同时由于真菌与人类细胞同为真核细胞,长期使用抗真菌药后对宿主具有相当的毒性.三氮唑类药物是目前治疗深部真菌感染的重要药物之一[1],代表药物有酮康唑、氟康唑、伊曲康唑等.该类药物抗菌谱广、毒性低、抗真菌作用强,但仍存在肝毒性较大、易产生耐药性等不良反应.     

The Chemical Behavior of Active Nitrogen

Active nitrogen, which is formed on passage of an electric discharge through a stream of nitrogen, is detected by a characteristic yellow afterglow. It can be determined quantitatively, e.g. by gas phase “titration” with nitric oxide. Active nitrogen reacts with many chemical elements, as well as with organic and inorganic compounds. Although nitrogen atoms are responsible for many of the reactions of active nitrogen, electronically excited molecules also play a role.     

CO(α3П)与CN(X 2Σ +)的能量转移反应

Energy-transfer reaction from metastable CO(a~3П) molecule to CN radical has been studied in a room-temperature flow reactor. The CN (B-X, △v=0, ±1, ±2) violet emission bands were obtained. The △v=0 sequence of CN(B) were analyzed by computer simulation. The vibrational temperature is 3400 K. By using the reference reaction CO(a)+NO, the formation rate constant of CN(B) has been measured, k_(CN)(B)=1.1×10~(-11) cm~3·molecule~(-1)·s~(-1).     

He*(23S)/CO2与CS2反应的化学发光

亚稳态原子（或分子）的传能反应，多年来一直受到人们的重视问．Cs。是涉及大气光化学、环境污染的重要分子之一，研究CS。与He”怦S）／CO。的碰撞反应是这些领域共同感兴趣的课题．Masaharu同详细地讨论了He”怦S）／CO与CS。的传能反应·本文在流动余辉装置上，研究了He“怦S）／CO。与CS。传能反应，对实验观察到的电子激发态产物CSt（A、CS（A，a）形成机理进行了讨论．1实验实验装置如图1所示·高纯的He体积分数为99．99％）通过两个装满了分子筛的液氮冷阶进一步提纯，然后由空。。阴极放电产生亚稳态He“炉S）原子·为…     

Reversible Chain Transfer Catalyzed Polymerization with Alkyl Iodides Generated from Alkyl Bromides by in Situ Halogen Exchange

Reversible chain transfer catalyzed polymerization(RTCP) is a practical and efficient process for the precise synthesis of polymers with special architecture by using simple phenols(2,4,6-trimethylphenol, TMP) or hydrocarbons(xanthene, XT) as efficient organocatalysts. Herein,alkyl iodide(R-I), which was generated from in situ bromine-iodine transformation of alkyl bromide(R-Br) with sodium iodide(NaI), was served as initiator to mediate RTCP with TMP or XT. MMA and other functional methacrylate...     

Structure–Reactivity Relationship in the Reaction of Highly Reactive Zinc with Alkyl Bromides

Zinc is different! Unlike with magnesium or lithium, the reactions of organic bromides with highly reactive zinc (Zn*) show sensitivity for the structure of the organic moiety. Selective insertions of Zn into tertiary C–Br bonds can be achieved [Eq. (a)]. Competitive kinetic techniques were used to quantify these findings.