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1.
6N(N-formyl-D-phenylalanyl)-deoxyamino--cyclodextrin and 6N(N-formyl-L-phenylal-anyl)-deoxyamino--cyclodextrin (I andII) were prepared. These new hosts formed intramolecular host-guest complexes and included naphthyl derivatives preferentially with a stoichiometry of 1:1. The inclusion behavior was different between I and II because the cavity shape formed with the CD cavity and the phenylalanine moiety of I was different from that of II.  相似文献   

2.
《Solid State Sciences》2003,5(9):1263-1270
The two new cluster compounds, Cs4Re6S8(N3)6·H2O (1) and Na2Mo6Br8(N3)6·2H2O (2), have been prepared via solution chemistry route, starting from the Cs4Re6S8Br6CsBr and Mo6Br12 precursors synthesized by solid state chemistry techniques, and structurally characterized (crystal data: Cs4Re6S8(N3)6·H2O (1): Orthorhombic, space group Pnam, a=10.0651(1) Å, b=15.8856(2) Å, c=20.1714(3) Å, V=3225.2(7) Å3, Z=4, dcalc=4.48 g cm−3, μ=27.43 mm−1; Na2Mo6Br8(N3)6·2H2O (2): Orthorhombic, space group Ibam, a=11.5643(3) Å, b=14.3959(5) Å, c=17.0340(7) Å, V=2835.8(2) Å3, Z=4, dcalc=3.63 g cm−3, μ=13.91 mm−1). Their structures revealed that in both cases, the M6Li8 cluster core remains unchanged in the starting and final compounds whereas the bromine apical ligands (Bra) are substituted by N3 azide groups leading to M6Li8(N3)a6 cluster unit. The new Cs4Re6S8(N3)6·H2O is the first example of a compound containing an octahedral rhenium cluster coordinated to azide groups.  相似文献   

3.
李再峰  罗富英 《合成化学》2000,8(5):439-441,446
为了寻找具有植物细胞激动素活性的新化合物,以苯并噻唑和取代苯胺为原料,将取代苯脲基引入到苯并噻唑的6-位上,合成了7个N-取代苯基N′-(6-苯并噻唑基)脲类化合物,它们的结构经元素分析、IR和^1HNMR确定,7个化合物的合成收率分别为74%,76%,85%,82%,70%,73%和72%。  相似文献   

4.
5.
采用超声波辐射使2,2,6,6-四甲基-4-哌啶酮(俗称三丙酮胺)和己二胺在室温条件下发生亲核加成反应,加成产物经减压蒸馏脱除水分子生成西佛碱,收率达75%;然后,在55-80℃、1.9~2.0MPa条件下,以W-7型或T-4型骨架镍作催化剂,对该西佛碱氢化,得到N,N′-二(2,2,6,6-四甲基-4-哌啶基)-1,6己二胺。  相似文献   

6.
7.
以三聚氰胺和硼酸为原料在水溶液中反应合成出了一种新的BCN化合物先驱体C3N6H6(H3BO3)2。XRD表征结果表明三聚氰胺和硼酸的最佳配比为1∶3(物质的量比)。用单晶X-射线衍射分析法测定了该化合物的晶体结构。该化合物属单斜晶系,空间群为P21/C,晶胞参数为a=0.3597(7)nm,b=2.0105(4)nm,c=1.4112(3)nm,α=90,°β=92.07(3),°γ=90,°V=1.0199(3)nm3,Z=4,D c=1.627g.cm-3,μ(MoKα)=0.144mm-1,F(000)=520。晶体结构经全矩阵最小二乘法修正,最终可靠因子R1=0.0519,wR2=0.1361。该化合物是由C3N6H6分子和H3BO3分子通过氢键加合组装形成的三维超分子结构化合物。  相似文献   

8.
Summary N,N,N,N-Tetramethylisophthalthioamide (Hmpt) was cyclopalladated with PdCl2 in hot dimethylsulphoxide to give [PdCl(mpt)]. The structure was determined by X-ray analysis. The thioamide is metallated at C(2) to act as an S528-01C528-02S tridentate anionic ligand. There is appreciable steric repulsion between the benzene ring H(4, 6) and the dimethylamino groups. The hydrogens and the methyl groups mutually deviate from the coordination plane in opposite directions. The stability of the fused 5,5-membered chelate ring formed by the S528-03C528-04S ligand seems to overcome the steric hindrance. Derivatives were prepared by replacement of the chloride ion with iodide, diethyldithiocarbamate, 4-tert-butylpyridine, or tri-n-butylphosphine, and characterized spectroscopically. The S528-05C528-06S-fused chelate ring was maintained in these derivatives.  相似文献   

9.
化学光谱法测定6N氧化铈中14个稀土杂质元素   总被引:2,自引:0,他引:2  
提出了二次分离富集-发射光谱法测定高纯氧化铈中14个稀土杂质元素的方法。所建立的方法分离时间短,富集了倍数高,化学光谱测定下限为0.33μg/g,适用于6N的氧化铈中14个稀土杂质元素的测定。  相似文献   

10.
Protonation of the reactive 1:1 intermediate produced in the reaction of acetylenic esters and triphenylphosphine by 6-aminouracil or 6-amino-N,N′-dimethyluracil leads to vinylphosphonium salts, which undergo Michael addition with the conjugate base of the NH acid to produce highly fanctionalized, salt-free phosphorus ylides in excellent yields.  相似文献   

11.
It has been shown that N,N’-diaryldiaza-18-crown-6 ethers with p-dimethylamino-and p-methoxy groups in the benzene ring (aryl is 4-Mc2NC6H4) (I) and 4-MeOC6H4 (II) form complexes with potassium and barium salts. The influence of these salts on the UV and 1H NMR spectra of crown ethers I and II has been studied. The stability constants (logβ) of the complexes increase in the series II · Ba(ClO4)2 (2.0), I · Ba(ClO4)2 (2.3), II · KBr (2.8), I · KBr (3.0). N,N’-bis(4-dimethylphenylamine)diaza-18-crown-6 (L, I) and its complex with barium perchlorate Ba(ClO4)2 · L (III) are characterized by X-ray crystallography. The crystals of I are monoclinic: a = 13.778(2) Å, b = 5.9731(9) Å, c = 17.542(3) Å, β = 106.65(1)°, V = 1383.1(4) Å3, Z = 2, space group P21/n, R = 0.0374 for 990 reflections with I > 2σ(I). The crystals of III are monoclinic: a = 17.275(4) Å, b = 8.017(2) Å, c = 26.935(4) Å, β = 100.47(2)°, V = 3669(1) Å3, Z = 4, space group C2/c, R = 0.0320 for 1897 reflections with I > 2σ(I). The molecules of I and III are centrosymmetric. In III, the Ba atom is in the center of substituted diaza-18-crown-6 (DA18C6). The Ba atom is coordinated by all six donor atoms of diaza-18-crown-6 (av. Ba-O, 2.779(3) Å; Ba-N, 3.004(4) Å) and four oxygen atoms of two asymmetrically bound perchlorate groups (Ba-O, 2.832(4) and 3.031(4) Å) arranged below and above the plane of substituted diaza-18-crown-6. The conformations of the macrocycle in free and coordinated L are different.  相似文献   

12.
Quasiclassical trajectory calculation (QCT) is used frequently for studying collisional energy transfer between highly vibrationally excited molecules and bath gases. In this paper, the QCT of the energy transfer between highly vibrationally excited C6F6 and N2 ,O2 and ground state C6F6 were performed. The results indicate that highly vibrationally excited C6F6 transferred vibrational energy to vibrational distribution of N2, O2 and ground state C6F6, so they are V-V energy transfer. Especially it is mainly V-V resonance energy transfer between excited C6F6 andground state C6F6, excited C6F6 transfers more vibrational energy to ground state C6F6 than to N2 and O2. The values of QCT, - (ΔEvib) of excited C6F6 are smaller than those of experiments.  相似文献   

13.
用稳态和时间相关荧光光谱,紫外-可见吸收光谱和傅立叶变换红外光谱等方法研究了Schiff碱N,N′-双水杨醛缩-1,6-己二胺(BSH)的光致变色行为,确定了光致变色的产物为双质子转移的酮式结构。  相似文献   

14.
The ground state and protonated state (quaternized salt) vibrational spectra (200–1800 cm−1) of the title amines are reported for various ring and/or methyl deuterated derivatives. Complete assignments are proposed and compared to those established for the parent hydrocarbons, benzene and biphenyl, and for the parent primary amines, aniline, p-phenylenediamine and benzidine. The electronic distribution, N(n)→ring(π) charge-transfer character and inductive effects are characterized from a vibrational point of view. Finally changes in the vibrational and electronic conformation upon protonation of the nitrogen atom are discussed. These results provide a fundamental basis for the vibrational investigation of excited states and reactive transients of aromatic amines.  相似文献   

15.
A recent crystallographic study has shown that, in the solid state, P(C(6)H(5))(4)N(3) and As(C(6)H(5))(4)N(3) have ionic [M(C(6)H(5))(4)](+)N(3)(-)-type structures, whereas Sb(C(6)H(5))(4)N(3) exists as a pentacoordinated covalent solid. Using the results from density functional theory, lattice energy (VBT) calculations, sublimation energy estimates, and Born-Fajans-Haber cycles, it is shown that the maximum coordination numbers of the central atom M, the lattice energies of the ionic solids, and the sublimation energies of the covalent solids have no or little influence on the nature of the solids. Unexpectedly, the main factor determining whether the covalent or ionic structures are energetically favored is the first ionization potential of [M(C(6)H(5))(4)]. The calculations show that at ambient temperature the ionic structure is favored for P(C(6)H(5))(4)N(3) and the covalent structures are favored for Sb(C(6)H(5))(4)N(3) and Bi(C(6)H(5))(4)N(3), while As(C(6)H(5))(4)N(3) presents a borderline case.  相似文献   

16.
化学光谱法测定6N氧化铕中14个稀土杂质元素   总被引:2,自引:2,他引:2  
本文利用有铕易被还原的特性,将铕还原为二价进行预分离,继以P507萃淋树脂柱进行二次分离,光谱测定富集物中14个稀土杂质元素,本方法富集倍数高达20,000倍,化学光谱测定了下限为0.65μg/g(∑RE)可满足6氧化铕产品分析的要求。  相似文献   

17.
在B3LYP/6-311+G(2d)//B3LYP/6-31C(d)计算水平下,考察了FeO+(6∑+)分子如何催化CO还原N2O微观机理.计算结果表明,FeO+(6∑+是一种有效的催化剂,其可从N2O中夺取一个O原子,然后再传递给CO,完成整个氧转移过程.结果发现,反应中可能生成各种过氧[Fe(O2)+]或双端氧(OFeO+)物种,其中前者比较稳定,后者更活泼.  相似文献   

18.
Okamoto等人曾报道Hetisine型骨架的N—C_6键断裂方法,但步骤多,操作复杂。由于没有活泼基因,打断 C_6—N 键很困难,曾用Von Braun 反应,Cope 反应,Hofmann 反应均未成功。今报道改良 Hofmann 反应方法——  相似文献   

19.
20.
The complexes of rare earth picrate with N,N,N',N'-tetraphenyl-3,6-dioxaoctanediamide(TDD),Eu(picc(TDD)] 2CH3CN and [ Y(pic)3(TDD)],have been synthesized.The crystal structures reveal that TDD at is as n tetradentate ligand,forming a ring-like coordination structure with its oxygen atoms together with one oxygen atom of the bidentate pterate In the Eu(Ⅲ) complex,the europium ion with a larger ionic radius lies out of the ring,while in the Y(Ⅲ) complex,the yttrium ion with a smaller ionic radius enters the cavity of the ligand.The structures of the complexes are greatly affected by the ionic radii due to participation of the picrates in coordination.  相似文献   

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