新型氮化硼陶瓷纤维先驱体——含硅聚硼氮烷的合成与表征

以三氯化硼、六甲基二硅氮烷为起始原料, 采用一步法合成了一种新型含硅氮化硼陶瓷纤维先驱体——含硅聚硼氮烷. 该法合成工艺简单, 且合成收率约为87%(质量分数). 采用元素分析、傅立叶红外光谱、核磁共振波谱、热机械分析、动态流变分析等对含硅聚硼氮烷的组成、结构和性能进行了表征. 结果表明, N—B为含硅聚硼氮烷先驱体的骨架结构, 其中, B, N主要以硼氮六环形式存在, 而Si则以Si—CH₃, Si—N形式存在. 该先驱体软化点为110 ℃, 具有优良的成型性, 在190 ℃的N₂气氛中可纺丝得到20～25 μm的有机纤维.     

甲胺/二甲胺共取代合成氮化硼先驱体聚硼氮烷

将三氯环硼氮烷(TCB)与甲胺/二甲胺进行共胺解取代反应, 首先制得了不同胺基的取代单体, 经过进一步热聚合反应合成了聚硼氮烷先驱体. 通过对不同单体的聚合产物组成与结构分析, 探讨了不同取代基对热聚合反应及产物结构的影响. 研究表明, 当控制甲胺/二甲胺摩尔比为1∶2, 聚合温度180 ℃, 获得的聚硼氮烷数均分子量为7603, 分子量分散系数为1.80, 熔点为83 ℃, 组成为BC_0.76N_1.39H_2.5, 该聚合物具有近似线性分子结构, 表现出优良的可纺性, 可制得平均直径10～15 μm的先驱体纤维, 为制备氮化硼纤维奠定了基础.     

氮化硼纤维先驱体的制备与表征

以三氯环硼氮烷为原料, 将其与正丙胺/异丙胺进行共取代反应, 制得了不同结构的取代单体, 再经热聚合反应获得了相应的聚硼氮烷先驱体. 通过分析不同正丙胺/异丙胺配比制得的聚合产物的组成与结构, 探讨了不同单体的胺基取代基对先驱体的聚合反应性及对产物结构的影响. 结果表明, 当正丙胺/异丙胺摩尔比为2∶1, 聚合温度为150 ℃, 反应时间为10 h时, 合成产物具有近似线性分子结构, 熔点为90 ℃, 具有良好的成丝性, 可获得平均直径10~20 μm, 组成为BC_1.27N_1.52H_x的先驱体纤维, 先驱体纤维再经不熔化处理及1200 ℃氨气高温煅烧等工艺可获得近化学计量比的氮化硼纤维.     

N,N′-亚乙基二(2-羟基-4-甲氧基二苯酮缩亚胺)Schiff碱的合成及抑菌活性

本文将 2 羟基 4 甲氧基二苯酮与乙二胺缩合成Ｓｃｈｉｆｆ碱 ,发现该Ｓｃｈｉｆｆ碱对紫外光的ＵＶ -Ａ、ＵＶ-Ｂ区都有较强吸收 ,对多种细菌有抑制作用。1　实验部分1 1　合成称取 2 羟基 4 甲氧基二苯酮 6 848ｇ( 30ｍｍｏｌ)于圆底烧瓶内 ,加 30ｍｌ 95 %乙醇 ,水浴加热至 5 0℃ ,磁力搅拌溶解 ,滴加 0 90 0ｇ( 1 5ｍｍｏｌ)乙二胺溶液 ,磁力搅拌 ,5 0～ 60℃回流反应 4ｈ ,析出黄色固体 ,冷却 ,过滤 ,用热的 95 %乙醇 ( 30～40℃ )溶液洗三次 ,再用乙醚洗一次 ,抽干。 40℃真空干燥 5ｈ ,得黄色粉末 ,产率 94%。1 2　表征Ｓｃｈｉ…     

N_n(CH)_(4-n)H_4(n=0-4)的环状结构与性质的理论研究

由于高能量密度材料HEDM在现代科技工业中的重要意义[1-2],其合成研究及应用也成为21世纪初固体推进剂研制发展的热点.氮氢化合物(NnHm)不稳定,在自然界中存在较少,大多都以反应中间体或裂解产物形式存在,此类化合物在含能材料方面有重要作用,因此人们从上个世纪50年代就开始重视对氮氢化合物的理论和实验的研究[3].     

8-羟基喹啉合十钒酸盐的研究——Ⅴ.镧(Ⅲ)、铈(Ⅲ)、钕(Ⅲ)、钐(Ⅲ)、铕(Ⅱ)和钆(Ⅲ)盐合成、鉴定与性质

我们曾报道过碱金属盐的合成.近来,这方面报道较多.本文研究了希土盐。实验一、合成称28克NaVO_3-4H_2O(分析纯)溶于500ml水中,加200ml HO_x的丙酮溶液(10克/100ml),搅匀分成七份,加热70℃时,每份分别滴加50ml溶有2克希土硝酸盐水溶液,调pH=6.2～6.8之间,搅拌30分钟,分出沉淀并干燥。二、组成分析C、H和N用元素分析仪,V和希土用原子吸收光谱仪和灼烧法。见表1。     

六氮杂大环配合物[Cd2(C30H48N6O2)(H2O)2Cl2]·2CH3OH的合成及其晶体结构

六氮杂大环化合物[3,7,11,19,23,27-六氮杂-33,34-二羟基-15,31-二甲基-三环-三十四烷-1(32),13,15,17(34),29(33),30-六烯(H2L)与CdCl2·2.5H2O在甲醇中反应,合成了新型双核镉冠醚配合物[Cd2(L)(H2O)2Cl2]·2CH3OH(1),其结构经IR...     

2-(氨基苯基)六氟异丙醇衍生物的合成

以六氟丙酮三水合物和芳香胺为原料,合成了一系列2-芳胺基六氟异丙醇化合物。研究了反应中原料配比、催化剂种类及用量、溶剂种类、反应时间及取代基对反应的影响。结果表明,在六氟丙酮三水合物用量为90 mmol,芳香胺用量为30 mmol,对甲基苯磺酸为催化剂,其用量为苯胺物质量的6%时,回流反应5～35h,反应的转化率和收率分别高达40.1%～100.0%,39.0%～99.0%。同时本文对六氟丙酮三水合物和无水六氟丙酮与苯胺的反应机理进行了比较,推测了六氟丙酮三水合物与苯胺的反应历程,并通过对其中间产物结构的表征进一步确认了该历程。     

含吡啶环氮(王)冠的合成

本文报道了新的含吡啶环的氮(王)冠的合成。以活泼双功能团化合物2,6-二(溴四基)-吡啶和N-对甲苯磺酰基取代的多乙撑基多胺(二乙撑三胺,三乙撑四胺)二钠盐直接缩合成环,得到含吡啶环的氮(王)冠化合物:3,6,9-三对甲苯磺酰基-3,6,9,15-四氮双环[9.3.1]十五环-1(15),11,13-三烯(A)和3,6,9,12-四对甲苯磺酰基-3,6,9,12,18-五氮双环[12.3.1]十八环-1(18),14,16-三烯(B)。(A)和(B)经用30%的HBr-CH_3COOH溶液处理,得到3,6,9,15-四氮双环[9.3.1]十五环-1(15),11,13-三烯(C)和3,6,9,12,18-五氮双环[12.3.1]十八环-1(18),14,16-三烯(D)。以上化合物均经元素分析、IR和1~H NMR.等鉴定。这种直接缩合的方法,具有反应条件温和、设备简单、操作简便等优点。     

α-卤代酰胺和硝酮的[3+3]环加成反应构建1,2,4-噁二嗪-5-酮类化合物

以六氟异丙醇作溶剂,α-溴代酰胺在三乙胺作用下脱去一分子溴化氢,原位生成氮杂氧杂烯丙基离子中间体,再与硝酮发生[3+3]环加成反应,高收率合成了一系列1,2,4-噁二嗪-5-酮类化合物,其结构经¹H NMR, ¹³C NMR, HR-MS(ESI)和X-射线单晶衍射确证。     

Bis(bis(trimethylsilyl)phosphino)silan [(Me3Si)2P]2SiH2 und 1,2-Bis(bis(trimethylsilyl)phosphino)disilan [(Me3Si)2PSiH2]2

The compounds H₂Si[P(SiMe₃)₂]₂ and [H₂SiP(SiMe₃)₂]₂ were prepared and characterized by ²⁹Si NMR, ³¹P NMR, IR and Raman spectroscopy. After thermolysis of these compounds no cyclic silylphosphanes could be detected in the reaction mixture,although this did contain P(SiMe₃)₃.     

Alkyl complexes of strontium and barium: synthesis and structural characterization of [(Me3Si)2(MeOMe2Si)C]2Sr(THF) and [(Me3Si)2(MeOMe2Si)C]2Ba(MeOCH2CH2OMe)

Metathesis between either SrI2 or BaI2 and 2 equiv of {(Me3Si)2(MeOMe2Si)C}K in THF yields the novel heavier alkali metal dialkyls {(Me3Si)2(MeOMe2Si)C}2M(L) [M(L) = Sr(THF) (2), Ba(DME) (3) (DME = 1,2-dimethoxyethane)] after recrystallization.     

Bildung siliciumorganischer Verbindungen. 110. Reaktionen von (Cl3Si)2CCl2, seiner Si-methylierten Derivate,von (Cl3Si)2CHCl, (Cl3Si)2C(Cl)Me und Me2CCl2 mit Silicium (Cu-Kat.)

Formation of Organosilicon Compounds. 110. Reactions of (Cl₃Si)₂CCl₂ and its Si-methylated Derivatives as well as of (Cl₃Si)₂CHCl, (Cl₃Si)₂C(Cl)Me and Me₂CCl₂ with Silicon (Cu cat.) The reactions of (Cl₃Si)₂CCl₂ 1 , its Si-methylated derivatives (Me₃Si)₂CCl₂ 8 , Me₃Si? CCl₂? SiMe₂Cl 9 , (ClMe₂Si)₂CCl₂ 10 , Me₃Si? CCl₂? SiMeCl₂ 11 , Cl₂MeSi? CCl₂? SiCl₃ 12 as well as of (Cl₃Si)₂CHCl 38 , (Cl₃Si)₂CClMe 39 and of Me₂CCl₂ with Si (Cu cat.) in a fluid bed reactor ( 38 and 39 also in a stirred solid bedreactor) arc presented. While (Cl₃Si)₂CCl₂ 1 yields C(SiCl₃)₄ 2 the 1,1,3,3-tetrachloro-2,2,4,4-tetrakis(trichlorsilyl)-1,3-disilacyclobutane Si₆C₂Cl₁₆ 3 and the related C-spiro linked disilacyclobutanes Si₈C₃Cl₂₀ 4 , Si₁₀C₄Cl₂₄ 5 , Si₁₂C₅Cl₂₈ 6 , Si₁₄C₆Cl₃₂ 7 this type of compounds is not obtained starting from the Si-methylated derivatives 8, 9, 10, 11 They Produce a number of variously Si-chlorinated and -methylated tetrasila- and trisilamethanes. However, Cl₂MeSi? CCl₂? SiCl₃ 12 forms besides of Si-chlorinated trisilamethanes also the disilacyclobutanes Si₆C₂Cl₁₅Me 34 and cis- and trans Si₆C₂Cl₁₄Me₂ 35 as well as the spiro-linked disilacyclobutanes Si₈C₃Cl₁₉Me 36 , Si₈C₃Cl₁₈Me₂ 37 . (Cl₃Si)₂CHCl 38 mainly yields HC(SiCl₃)₃ 31 and also the disilacyclobutanes cis- and trans-(Cl₃Si)HC(SiCl₂)₂CH(SiCl₃) 41 and (Cl₃Si)₂C(SiCl₂)₂CH(SiCl₃) 45 the 1,3,5-trisilacyclohexane [Cl₃Si(H)C? SiCl₂]₃ 44 as well as [(Cl₃Si)₂CH]₂SiCl₂, and (Cl₃Si)₂CClMe 39 mainly yields (Cl₃Si)₂C?CH₂and (Cl₃Si)₂besides of HC(SiCl₃)₃, MeC(SiCl₃)₃and (Cl₃Si)₃C? SiCl₂Me.,. Me₂CCl₂ 59 mainly yields Me(Cl)C?CH₂, Me₂CHCl and HCl₂Si? CMe₂? SiCl₃, besides of Me₂C(SiCl₃)₂ and Me₂C(SiCl₂H)₂ Compound 3 crystallizes triclinically in the space group P1 (Nr. 2) mit a = 900,3, b = 914,0, c = 855,3 pm, α = 116,45°, β = 101,44°, γ = 95,86° and one molecule per unit cell. Compound 4 crystallizes monoclinically in thc space group C2/c (no. 15) with a = 3158.3,b = I 103.7, c = 2037.4 pm, β = 1 16.62° and 8 molecules pcr unit cell. The disilacyclobutane ring of compound 3 is plane, showing a mean distance of d (Si-C) =19 1.8 pm and the usual deformations of endocyclic angles: α_Si = 94,2°> 85,8° = α_C.The spiro-linked disilacyclobutane rings of compound 4 are slightly folded by a mean angle of (19.0°). Their mean distances were found to be d (Si? C) = 190.4 pm relating to the central carbon atom and 192.0 pm to the outer ones, respectively. The deformations of endocyclic angles: α_Si = 93,9°> 84,4° = α_C are comparable to those of compound 3.     

Guanidinate derivatives of rare-earth metals. The synthesis, properties, and molecular structures of the complexes {(Me3Si)2NC(NPri)2}3Nd, {(Me3Si)2NC(NCy)2}3Lu, and {(Me3Si)2NC(NPri)2}2HC(NPri)2}Nd

The reactions of anhydrous LnCl₃ (Ln = Nd or Lu) with three equivalents of {(Me₃Si)₂NC(NR)₂}Li (R = Prⁱ or Cy; Cy is cyclohexyl) in THF afforded the corresponding tris(guanidinate) derivatives of lanthanides {(Me₃Si)₂NC(NR)₂}₃Ln (Ln = Nd, R = Prⁱ, (1); Ln = Lu, R = Cy (2)), which were isolated after the recrystallization from hexane in 82 and 88% yields, respectively. The complex {(Me₃Si)₂NC(NCy)₂}₂{HC(NCy)₂}Nd (3) containing two guanidinate ligands and one formamidinate ligand was isolated in attempting to synthesize the bis(guanidinate) borohydride derivative by the reaction of {(Me₃Si)₂NC(N-Cy)₂}Na with Nd(BH₄)₃(THF)₂ (in a molar ratio of 2: 1) in THF. This complex is apparently formed as a result of the fragmentation and redistribution of the guanidinate ligands. The X-ray diffraction study showed that in the crystalline state compounds 1–3 are mononuclear complexes containing no coordinated Lewis bases.     

Die Reaktionen von tBu2P–P=P(Me)tBu2 und (Me3Si)tBuP–P=P(Me)tBu2 mit PR3

The Reactions of ^tBu₂P–P=P(Me)^tBu₂ and (Me₃Si)^tBuP–P=P(Me)^tBu₂ with PR₃ ^tBu₂P–P=P(Me)^tBu₂ ( 1 ) reacts at 20 °C with PMe₃, PEt₃, P(c‐Hex)₃, P(p‐Tol)₃, PPh₂Me, PPh₂Et, PPhEt₂, PPh₂ⁱPr, PPh₃ and P(NEt₂)₃ yielding ^tBu₂P–P=PR₃ and ^tBu₂PMe; however, P^tBu₃, P^tBu₂(SiMe₃) and ^tBu₂PCl don't. ^tBu₂PH and 1 form ^tBu₂P–PH–P^tBu₂ which yields ^tBu₂P–P=PEt₃ when treated with PEt₃. Ph₂PH, ^tBuPH₂, PH₃, Ph₂PCl and EtOH don't substitute the ^tBu₂PMe group in 1 , instead, the molecule is decomposed. With PEt₃, (Me₃Si)^tBuP–P=P(Me)^tBu₂ forms (Me₃Si)^tBuP–P=PEt₃. The compounds ^tBu₂P–P=PR₃ decompose at 20 °C to different degrees giving P‐rich consecutive products of the phosphinophosphinidene.     

Synthese eines Titana-Oxacyclohexanringes durch kontrollierte Ringöffnung von Tetrahydrofuran. Kristallstrukturen von [Ti(CH2)4O{Me2Si(NBut)2}]2, [TiCl{Me2Si(NBut)2}]3(μ3-O)(μ3-Cl) und [Li2(THF)3{Me2Si(NBut)2}]

Synthesis of a Titana-Oxacyclohexane Ring by Controlled Ring Opening of Tetrahydrofurane. Crystal Structures of [Ti(CH₂)₄O{Me₂Si(NBu^t)₂}]₂, [TiCl{Me₂Si(NBu^t)₂}]₃(μ₃-O)(μ₃-Cl), and [Li₂(THF)₃{Me₂Si(NBu^t)₂}] [TiCl₃(THF)₃] reacts with [(Bu^tNLi)₂SiMe₂]₂ in diethyl ether at –35 °C under redox disproportionation and formation of the yellow titana(IV)-oxacyclohexane complex [Ti(CH₂)₄O{Me₂Si(NBu^t)₂}]₂. According to the crystal structure analysis the titanium atoms are linked to form centrosymmetric dimers via the oxygen atoms of the Ti(CH₂)₄O six-membered rings, which are in chair conformation. Along with the nitrogen atoms of the chelating [Me₂Si(NBu^t)₂]^2– ligands the titanium atoms obtain a distorted trigonal-bipyramidal surrounding. While [TiCl{Me₂Si(NBu^t)₂}]₃(μ₃-O)(μ₃-Cl) with a cluster-like structure is obtained as a by-product. According to the crystal structure analysis of [Li₂(THF)₃ · {Me₂Si(NBu^t)₂}], which is involved in the synthesis reaction, the two lithium atoms are connected with both the nitrogen atoms of the t-butyl amide groups and bridged via an oxygen atom of one of the THF molecules.