N，N－二甲基甘氨酸乙酯分解反应机理的理论研究

利用量子化学计算方法MP2／6－31＋G^*研究了N，N－二甲基甘氨酸乙酯在气 相中热分解反应机理，并计算了反应的协同性，得出此反应是一个多步反应过程。 主要有两个阶段：第一个阶级是N，N－二甲基甘氨酸乙酯热分解产生N，－N二甲基 甘氨酸中间体和乙烯，第二个阶段是N，N－二甲基甘氨酸进一步分解生成三甲氨和 二氧化碳。第一个反应阶段为速率控制步骤。研究表明，该反应机理是一个非协同 的质子转移过程。计算结果与实验值吻合。     

甘氨酸在N,N-二甲基甲酰胺水溶液中的体积性质

用Anton Paar型55精密数字密度计测定了甘氨酸在N,N-二甲基甲酰胺(DMF)水溶液中的密度,计算了甘氨酸的表观摩尔体积、极限偏摩尔体积、迁移偏摩尔体积和理论水化数,讨论了DMF的结构对甘氨酸迁移偏摩尔体积和理论水化数的影响。结果表明,甘氨酸在DMF水溶液中的迁移偏摩尔体积为正值,并且随着溶液浓度增大而增大。在DMF水溶液中的理论水化数比在纯水中的小,并且随着DMF浓度的增大而减小。把上述计算结果与在N,N-二甲基乙酰胺(DMA)水溶液中的实验结果进行了比较。     

铕—N，N—二（N—亚甲基琥珀酰亚胺）甘氨酸—1，10—二氮杂菲三元配合物的

合成了N,N－二（N－亚甲基琥珀酰亚胺）甘氨酸,并以元素分析、IR、^1H NMR和质谱进行表征,实现中发现铕（Ⅲ）与N,N－二（N－亚甲基琥珀酰亚胺）甘氨酸和1,10二氮杂菲形成的配合物具有光致变色的性质。在铕变色物种里,铕离子与N,N－二（N－亚甲基琥珀酰亚胺）甘氨酸中的羧基,1,10－二氮杂菲中的氮原子相结合,同时也可能与水分子和羟基基团结合。     

N,N-二(邻硝基苯氨基乙基)甘氨酸糖酯的合成

在氢氧化钠和四丁基溴化铵存在下,将N,N-二(邻硝基苯氨基乙基)甘氨酸分别与O-乙酰基溴代葡萄糖、O-乙酰基溴代半乳糖、O-乙酰基溴代乳糖和O-乙酰基溴代木糖作用,制得N,N-二取代甘氨酸的对应乙酰基糖酯。由元素分析、IR、MS和¹HNMR确认了4个的糖酯的结构。关键词N,N-二(邻硝基苯氨基乙基)甘氨酸糖酯,溴代葡萄糖,溴代乳糖,溴代木糖,葡萄糖酸酯。     

N,N-二取代甘氨酸酯的合成及其经皮促渗活性

合成了4个新的N,N-二取代甘氨酸酯,其结构经^1HNMR谱、IR谱、MS-ESI谱和元素分析确证。在改良的Franz扩散池上,用离体裸鼠皮作生物膜,扑热息痛或消炎痛作药物模型进行经皮促渗活性对比试验。结果显示：N,N-二甲基甘氨酸-（E）-3,7-二甲基-2,6-辛二烯酯（2a）具有出色的促透活性,含2．5％的2a促进扑热息痛、消炎痛经皮渗透的效果分别是Azone的2．1和2．6倍,且时滞缩短,超过DDAA的经皮促渗活性;而N,N-二甲基甘氨酸-6-戊氧基-1-己酯（2b）的经皮促渗活性接近Azone,且时滞更短。     

N,N-二取代甘氨酸酯的ESI-MS/MS研究

应用多级质谱（＋）ESI—MS／MS考察了八种N,N-二取代甘氨酸酯化合物的质谱行为,并对其质谱裂解途径进行解析,为表征该类化合物提供了依据。     

离子选择电极法测定N,N—二甲基膦酸基甘氨酸与钙的络合物组成和稳定常数

N,N—二甲基膦酸基甘氨酸[N,N—Bis(pheosphonomethyl)glycine,以下简称NBPG]结构式为在农业上作为植物生长调节剂,有明显的增糖增产作用。从化学结构上看,又是很好的络合剂。B.BynozkuHa等人曾研究过与Fe~(3+)、Mn~(2+)、Pb~(2+)的络合反应。本文用钙离子选择电极法测定了NBPG与Ca~(2+)生成络合物的组成和稳定常数;同时测定了NBPG的各级电离常数,为NBPG的开发应用奠定基础。     

N—O键解离焓的密度泛函理论研究

在高精度计算方法G3和G3B3的基础上,比较了密度泛函理论(DFT)十几种方法对N—O键解离焓(BDE)相对于实验值的计算精度,发现用B3P86方法计算15种化合物N—O键的BDE,均方根误差最小,仅为6.36kJ·mol-1,计算值与实验值的线性相关系数为0.991.在此基础上,用该方法分别计算了非芳香化合物及芳香化合物的N—O键BDE.通过自然键轨道分析,发现部分N—O键的BDE与N—O键的键长、原子电荷密度及键级之间存在定量关系.此外,在B3P86方法的基础上预测了几种典型的杂环芳香化合物N—O键BDE值.     

稀土N,N,N"-三(3,5-二硝基苯磺酰基)-1,4,7-三氮杂环壬烷配合物的合成、表征及荧光性质

合成了 6种新型的稀土 (镧、铈、镨、钕、钐、铕 ) N ,N ,N " -三 (3 ,5 -二硝基苯磺酰基 ) -1 ,4,7-三氮杂环壬烷配合物 ,通过元素分析、红外光谱、紫外光谱和核磁共振氢谱对配合物进行了表征、确定了组成 .研究了La( )及 Ce( )配合物的荧光性质 ,结果表明 ,稀土的芳香基氮杂大环配合物具有优良的发光性能     

对-二氮杂萘 N,N′-二氧化物光解产物的 ESR 研究

芳香 N-氧化物在光激发下发生脱氧、重排、环扩大和环缩小等反应.但 N-氧化物的初级光化学反应是否涉及自由基中间体的过程却未见文献报道.本文利用电子自旋共振技术研究两种对-二氮杂萘 N,N′-二氧化物(1,2)在光解过程中所生成的自由基中间体.     

Synthesis of Five-Membered N,N,N- and N,N,N,N-Heterocyclic Compounds: Applications of Microwaves

The development of new strategies for the synthesis of small-sized heterocycles has remained a highly attractive but challenging proposition. An overview of the application of microwave irradiation to the synthesis of five-membered heterocyclic compounds containing three and four nitrogen atoms is presented, focusing on the developments in the past 5–10 years. This contribution covers the literature concerning the total synthesis of N,N,N- and N,N,N,N-heterocycles. The literature data are summarized based on the size and type of cycles.     

Extraction of uranium(VI) with N,N,N′,N′-tetrabutylmalonamide and N,N,N′,N′-tetrahexylmalonamide

A new diamide N,N,N′,N′-tetrahexylmalonamide (THMA) was synthesized, characterized and used in the extraction of U(VI) from nitric acid solutions. N,N,N′,N′-tetrabutylmalonamide (TBMA) was also studied to test the steric hindrance. Factors affecting this extraction system, the concentration of the extractant, aqueous nitric acid and NaNO₃ and the temperature were investigated. The IR spectral study was also made of the extracted species.     

Isomerization of N,N,N′-trifluoroalkylamidines

Conclusions The syn-isomers of N,N,N-trifluorobutyramidine and N,N,N-trifluoromonochloroacetamidine are isomerized in the presence of HCl to the anti-form. The isomerization of the syn-isomer of N,N,N-trifluoromonochloroacetamidine also proceeds in the presence of ethanol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2159–2160, September, 1973.     

Poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide), N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide as new reagents for conjugate addition of indole, pyrrole with α,β-unsaturated ketones

Poly(N,N??-dibromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS] and N,N,N??,N??-tetrabromobenzene-1,3-disulfonamide[TBBDA] were used as efficient reagents for conjugate addition of indole and pyrrole with ??,??-unsaturated ketones and also, double-conjugate 1,4-addition of indoles to dibenzylidenacetones.     

N,N′-dialkyl-N,N′-dinitrosulfodiamides

N,N-dinitrosulfodiamides are formed in the nitration of sulfodiamides with concentrated nitric acid or nitronium borofluoride, and also on substitutional nitration of the corresponding N,N-di-tert.-butyl derivatives with those reagents. Sulfuryl chloride reacts with the disodium salt of ethylene N,N-dinitramine to produce 2,5-dinitro-1,2,5-thiadiazolidine-1,1-dioxide. The corresponding N-nitrosulfamides are formed when nitramine salts react with methane sulfochloride.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1812–1815, August, 1989.     

A Facile Synthesis of 1,4-Diketones from Organolithium Reagents and N,N,N′,N′-Tetramethylsuccinamide

The reaction of organolithium reagents (alkyl, aryl, heteroaryl) with N,N,N′,N′-tetramethylsuccinamide at 0 °C gives good yields of the corresponding 1,4-diketones.     

Hyperfine coupling constants of the azafullerenes C19N, C59N, C69N, and C75N

The isomers of the nitrogen-substituted fullerenes (azafullerenes) C19N, C59N, C69N, and C75N are examined using all-electron Gaussian atomic orbital basis density functional theory, to determine the doublet radical geometries and hyperfine coupling constants. We find that the inaccuracy of previously calculated hyperfine coupling constants of C59N resulted from a poor treatment of the geometry optimization. We find that UB3LYP minimization of the radical geometry in the 6-31G basis, followed by single-point evaluation of the hyperfine constants in which an expanded basis is used on the atomic sites of interest, forms an efficient compromise between computational cost and accuracy with respect to experimental hyperfine constants. Using this approach, we assign the hyperfine signals observed in experiments on the C69N radical by calculating the hyperfine coupling constants for all five of the isomers and examine the electron spin density distribution. Finally, we present predicted hyperfine coupling constants for the isomers of C19N and C75N for use in the interpretation of future experiments.     

Dendrimers Functionalized with Palladium Complexes of N-, N,N-, and N,N,N-Ligands

Pyridine, pyridine imine, and bipyridine imine ligands functionalized by a phenol have been synthesized and characterized, in many cases by X-ray diffraction. Several of these N-, N,N-, and N,N,N,-ligands have been grafted onto the surface of phosphorhydrazone dendrimers, from generation 1 to generation 3. The complexation ability of these monomers and dendrimers towards palladium(II) has been assayed. The corresponding complexes have been either isolated or prepared in situ. In both cases, the monomeric and dendritic complexes have been tested as catalysts in Heck couplings and in Sonogashira couplings. In some cases, a positive dendritic effect has been observed, that is, an increase of the catalytic efficiency proportional to the dendrimer generation.     

N,N’-二苯基-N,N’-二(9,9-二甲基芴-2-基)-9-己基-(4,4’-二胺基苯基)咔唑的合成方法及表征

以2,7-二溴咔唑为原料经过N-烷基化、Suzuki偶联反应、Buchwald-Hartwig偶联反应合成了有机发光二极管(OLED)空穴传输材料N,N’-二苯基-N,N’-二(9,9-二甲基芴-2-基)-9-己基-(4,4’-二胺基苯基)咔唑,利用NMR、IR和熔点等分析方法对产物结构进行了表征,并通过TG、UV-Vis及荧光光谱研究了物质的热稳定性和光学性能。     

Iodide, azide, and cyanide complexes of (N,C), (N,N), and (N,O) metallacycles of tetra- and pentavalent uranium

In contrast to the neutral macrocycle [UN*(2)(N,C)] (1) [N* = N(SiMe(3))(3); N,C = CH(2)SiMe(2)N(SiMe(3))] which was quite inert toward I(2), the anionic bismetallacycle [NaUN*(N,C)(2)] (2) was readily transformed into the enlarged monometallacycle [UN*(N,N)I] (4) [N,N = (Me(3)Si)NSiMe(2)CH(2)CH(2)SiMe(2)N(SiMe(3))] resulting from C-C coupling of the two CH(2) groups, and [NaUN*(N,O)(2)] (3) [N,O = OC(═CH(2))SiMe(2)N(SiMe(3))], which is devoid of any U-C bond, was oxidized into the U(V) bismetallacycle [Na{UN*(N,O)(2)}(2)(μ-I)] (5). Sodium amalgam reduction of 4 gave the U(III) compound [UN*(N,N)] (6). Addition of MN(3) or MCN to the (N,C), (N,N), and (N,O) metallacycles 1, 4, and 5 led to the formation of the anionic azide or cyanide derivatives M[UN*(2)(N,C)(N(3))] [M = Na, 7a or Na(15-crown-5), 7b], M[UN*(2)(N,C)(CN)] [M = NEt(4), 8a or Na(15-crown-5), 8b or K(18-crown-6), 8c], M[UN*(N,N)(N(3))(2)] [M = Na, 9a or Na(THF)(4), 9b], [NEt(4)][UN*(N,N)(CN)(2)] (10), M[UN*(N,O)(2)(N(3))] [M = Na, 11a or Na(15-crown-5), 11b], M[UN*(N,O)(2)(CN)] [M = NEt(4), 12a or Na(15-crown-5), 12b]. In the presence of excess iodine in THF, the cyanide 12a was converted back into the iodide 5, while the azide 11a was transformed into the neutral U(V) complex [U(N{SiMe(3)}SiMe(2)C{CHI}O)(2)I(THF)] (13). The X-ray crystal structures of 4, 7b, 8a-c, 9b, 10, 12b, and 13 were determined.