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1.
通过2 ,3 ,4 ,6四 O乙酰 基β D吡 喃型 葡萄 糖 异硫 氰酸 酯( 3) 和 2 ,3 ,4三 O乙 酰基β D吡 喃型木糖 异硫氰酸 酯( 4) 与 取代的芳 基酰 肼(5) 的亲 核加 成反 应合 成了 10 个 1芳酰 基4(1′ N2′,3′,4′,6′四 O乙 酰基β D 吡 喃 型葡 萄 糖 基) 氨基 硫 脲(6) 和7 个 1芳 酰 基4( 1′ N2′,3′,4′三 O乙酰 基β D吡喃 型木糖 基) 氨基硫 脲( 7) ,并 经脱除乙 酰基得 到10 个1芳 酰基4(1′ Nβ D吡喃型 葡萄糖 基) 氨基硫 脲(8) 和 7 个1芳酰 基4(1′ Nβ D吡喃型 木糖 基) 氨基 硫脲( 9) , 所得化合物 经元素 分析, I R,1 H N M R 确证 了结构  相似文献   

2.
以4-羟基联苯,4-羟基-4′-氰基联苯和手性L-2-甲基丁醇为原料,通过三条路线合成了铁电性液晶中间体4-羟基联苯-4′-甲酸-L-2-甲基丁醇酯.5步法(醚化、酰化、溴仿、水解和酯化)总收率35.6%;3步法(酰化、溴仿和酯化)总收率50.7%;而以4-羟基-4′-氰基联苯为原料的一步合成法收率64.4%.中间体和目标产物的结构经1H NMR和IR确证.  相似文献   

3.
以4-羟基联苯,4-羟基4’-氰基联苯和手性L-2-甲基丁醇为原料,通过三条路线合成了铁电性液晶中间体4-羟基联苯4’-甲酸-L-2-甲基丁醇酯。5步法(醚化、酰化、溴仿、水解和酯化)总收率35.6%;3步法(酰化、溴仿和酯化)总收率50.7%;而以4-羟基-4'-氰基联苯为原料的一步合成法收率64.4%。中间体和目标产物的结构经^1H NNR和IR确证。  相似文献   

4.
以4,4′(α,ω辛二酰氧)二苯甲酰氯,2,5二(4十六烷氧基苯甲酰氧基)对苯二酚和4,4′二(β羟基乙氧基)联苯为单体,通过溶液缩聚反应合成了一系列新的含两种液晶基元的串型液晶共聚物.共聚物通过GPC、DSC、TG、WAXD和偏光显微镜等方法表征.发现所有的共聚物加热至各自的熔点以上都能形成液晶态,在液晶态可以观察到大理石或破碎焦锥织构.所有共聚物的熔点(Tm)和液晶态清亮点(Ti)随聚合物中2,5二(4十六烷氧基苯甲酰氧基)对苯二酚用量的改变呈规律性变化.  相似文献   

5.
用低价钛试剂(TiCl4-Zn)与3-氧代-1-(3′,4′-亚甲二氧苯基)-3-苯基丙基-1-丙二腈反应合成了非对映消旋体(1S,4R;1R,4S)和(1S,4S:1R,4R)2-氨基-3-氰基-1-苯基-4(3-4-亚甲二氧苯基)-2-环戊烯-1-醇,用X射线衍射分析确定了这两个异构体的相对构型。  相似文献   

6.
合成了一类新型的含偶氮基和对甲苯基氨基甲酰基的多功能引发剂,4,4’偶氮二(4氰基戊酰对甲苯胺).测定其偶氮键热分解反应为一级反应,分解活化能为1246KJ·mol-1.利用引发剂中对甲苯氨基甲酰与Ce(IV)盐的氧化还原引发单体聚合,得到含有偶氮端的预聚物,它在65℃热分解引发另一单体聚合生成嵌段共聚物.纯化后的共聚物,经IR等结构表征为嵌段共聚物  相似文献   

7.
丙酰氯同四氢噻唑2硫酮及(R)四氢噻唑2硫酮4羧酸乙酯反应生成N酰基四氢噻唑2硫酮2a及光学活性N酰基(R)四氢噻唑2硫酮4羧酸乙酯2b,而α溴代丙酰氯分别同四氢噻唑2硫酮及(R)四氢噻唑2硫酮4羧酸乙酯反应得到四氢噻唑2α溴代丙酰硫酯3a及光学活性4乙氧羰基四氢噻唑2α溴代丙酰硫酯3b.用半经验的量子化学PM3方法研究了反应物和产物的电子结构和反应的焓变,得到了反应物1a异构化的过渡态.  相似文献   

8.
四(4-硝基苯基)卟啉和四(4-氨基苯基)卟啉的合成   总被引:20,自引:1,他引:20  
四(4氨基苯基)卟啉(TAPP)是含有4个反应活性基团的卟啉衍生物,可在模拟某些生物过程或氧化还原反应的树枝状或簇状分子中作为富电子中心,也可直接用来制备光电器件或作为光电功能聚合物的功能单体和交联剂,因此,TAPP的合成研究具有重要意义[1]....  相似文献   

9.
把硫原子引入液晶分子,取代液晶分子中的碳原子和氧原子可得到含硫代苯甲酸酯[1]、砜基[2]、亚砜基[3]和亚磺酸基[4]等结构的液晶化合物,性能独特.但含磺酸酯基的液晶化合物尚未见文献报道.本文应用N,N二环己基碳二亚胺(DCC)和4N,N二甲...  相似文献   

10.
以大孔聚苯乙烯氯球为原料,在氮气保护及氢化钠存在下,将其与4 氨基吡啶及硫酸二甲酯反应,制成聚苯乙烯支载N 苄基 N 甲基氨基吡啶(BMAP)催化剂.与文献相比,该法具有反应时间短,价格低,制备的BMAP活性高等特点.经过元素分析、FTIR及MAS1H NMR对其结构进行表征.利用该催化剂进行了芳樟醇的乙酰化反应,对影响反应的诸因素如反应物料比,反应时间,反应温度等进行了讨论,芳樟醇的转化率为99%以上,总酯率为95%左右,其中芳樟酯的产率为60%以上(目前工业上使用H3PO4催化剂芳樟酯产率为50%左右).催化剂通过再生连续使用五次,活性无明显下降.  相似文献   

11.
The crystal structure of LaIr4B4 has been refined from single crystal counter data. LaIr4B4 is tetragonal,P42/n,Z=2, isotypic with NdCo4B4, |F|/|F o|=0.039 for 312 independent reflections [|F o|>2 (F o)]. ThIr4B4 and ThOs4B4 also belong to the NdCo4B4-type structure. URu4B4 and UOs4B4 were found to crystallize with LuRu4B4-type structure. The crystal chemistry of (RE)T 4B4-phases is discussed and simple geometric relations are shown to exist between them.Dedicated to Prof.B. T. Matthias in celebration of his 60th birthday.  相似文献   

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14.
On K4PbO4 and Rb4PbO4 For the first time single crystals of K4[PbO4] have been prepared by heating K4PbO3 in O2. The structure has been refined [K4[PbO4]: 3029 I0(hkl), four circle diffractometer PW 1100, ω-scan, MoKα, R = 6.73%, Rw = 6.64%, P1 ; a = 658.62(15), b = 658.41(12), c = 986.64(21) pm, α = 79.74(2)°, β = 108.45(2)°, γ = 112.49(2)°, dx = 3.79 g · cm?3, dpyk = 3.78 g · cm?3, Z = 2; Rb4[PbO4]: a = 686.94(18), b = 684.43(18), c = 1020.73(21) pm, α = 79.28(2)°, β = 108.40(2)°, γ = 113.02(2)°, dx = 4.87 g · cm?3, dpyk = 4.85 g · cm?3, Z = 2, (from Rb2PbO3 and Rb2O)]. Both compounds are isotypic with K4SnO4. The Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated.  相似文献   

15.
Vibrational Spectra of As4S4 and As4Se4 The vibrational spectra of solid α- and β-As4S4 and the Raman spectrum of molten As4S4 have been recorded. The assignments of the frequencies are proposed mainly based on polarization data. The Raman melt spectra suggest that As4S4 molecules (symmetry D2d) are retained in the molten state. A partial decomposition of the melt by prolonged laser irradiation was observed. The Raman spectrum of solid As4Se4 is presented and the frequencies are tentatively assigned to an As4Se4 molecule of the cradle type, possessing D2d symmetry.  相似文献   

16.
Die erstmals dargestellten isotypen Verbindungen Ba4SiAs4, Ba4GeAs4, Sr4SiAs4 und Sr4GeAs4 kristallisieren kubisch, Raumgruppe P4 3n, mit 8 Formeleinheiten in der Elementarzelle: In den Strukturen liegen isolierte, d.h. nur von Ba-Ionen umgebene SiAs - bzw. GeAs -Tetraeder vor. Die Verbindungen sind die bisher eindrucksvollsten Beispiele für Zintlphasen mit komplexen Anionen. Zintl Phases with Isolated SiAs4 or GeAs4 Anions: Preparation and Structure of Ba4SiAs4, Ba4GeAs4, Sr4SiAs4, and Sr4GeAs4 The new compounds Ba4SiAs4, Ba4GeAs4, Sr4SiAs4, and Sr4GeAs4 have been prepared and their structures determined. They crystallize in the cubic system, P4 3n, with axes: data see “Inhaltsübersicht”. There are isolated SiAs or GeAs tetrahedra in the structures. The compounds can be interpreted as Zintl phases with complex anions.  相似文献   

17.
Ab initio calculations have been performed on B4H4, B4Cl4 and B4F4 in order to aid our understanding of the bonding in these compounds, which is presumably based on a tetrahedral boron cage. This cage has only 8 electrons and so is less than that expected on the basis of the usual framework electron counting rules. Basis sets with polarisation functions were used at the SCF, CI and CPF levels of theory to confirm that the T d structures are indeed more stable than the D 4h ones. Davidson-Roby population analyses were able to show that many factors, including 3-centre 2-electron bonding and backbonding from the ligand to the boron cage, are of importance in determining the relative stability of the three compounds, of which B4Cl4 is the only one that has yet been observed experimentally.  相似文献   

18.
《Liquid crystals》1997,23(1):9-16
Two families of liquid crystalline compounds have been synthesised, the 4-butyl-4- alkoxyazobenzenes and the 4-pentyl-4-alkoxyazobenzenes; for the second family results are presented for the first time for alkoxy chains longer than butyl. The results for both families have been obtained up to the octadecyl homologues. In both families, on the basis of DSC, polarizing microscopy and thermo-optical analysis, a rich polymorphism has been detected (maximum tetramorphism). The smectic properties start with the hexyl derivative (for the butyl family) and with the heptyl derivative (for the pentyl family). Strong odd-even effects for the temperatures of clearing in both groups of compounds were detected. Our results are compared with those of de Jeu et al. and of Adomenas et al. for the 4-butyl-4- alkoxyazobenzenes, for which only one smectic modification was described.  相似文献   

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Energy differences, ΔXS‐t (X = E, H and G) (ΔXS‐t = X(singlet)‐X(triplet)) between singlet (s) and triplet (t) states are calculated at B3LYP/6‐311++G (3df,2p). The DFT calculations show that the triplet state of C4H4C is a ground state with planar conformer respect to its corresponding nonplanar singlet state. Both singlet and triplet states of C4H4M (M = Si, Ge, Sn and Pb) have a planar conformer with the singlet ground state. Four isodesmic reactions are presented for determining the stability energies, SE. NICS calculations are carried out for C4H4M to determine the aromatic character.  相似文献   

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