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1.
12-Methyl-l, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo[2, 3-a]quinolizine (1) is synthesized through a new route developed in our laboratory. The most important step in this synthesis is the condensation of I-methyltryptophyl bromide (4) with 2-piperidone (5) to give N -(2-(1-methylidol)-3-ylethyl)-2-piperidone (6) in good yield (70%). The synthesis of 1-benzoyl-1, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo(2, 3-a]quinolizine (2) and 1-phenylcarbinol-1, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo[2, 3-a]quinolizine (3) follow the method developed by Wenkert. But the yield of tetrahydropyridine 9 from partial hydrogenation of pyridinum bromide 8 with 10% palladium-charcoal is 84% which is much higher than the best yield (40%) in the literature, since the phenyl group contribute additional stability.  相似文献   

2.
Chain‐folded lamellar crystals of the ten even‐even nylons: 6 6, 8 6, 8 8, 10 6, 10 8, 10 10, 12 6, 12 8, 12 10, and 12 12 have been grown from solution and their morphologies and structures studied using transmission electron microscopy, both imaging and diffraction. Sedimented mats were examined using X‐ray diffraction. The solution‐grown crystals are lath‐shaped lamellae and diffraction from these crystals, at room temperature, reveals that three crystalline forms are present in differing ratios. The crystals are composed of chain‐folded, hydrogen‐bonded sheets, the linear hydrogen bonds within which generate a progressive shear of the chains (p‐sheets). The sheets are found to stack in two different ways. Some p‐sheets stack with a progressive shear, to form the “αp structure”; others sheets stack with an alternate stagger, to form the “βp structure”. Both the αp and βp structures give two strong diffraction signals at spacings of 0.44 nm and 0.37 nm; these signals represent a projected intrasheet interchain distance (actual value 0.48 nm) and the intersheet spacing, respectively. Preparations of nylons 6 6, 8 6, 8 8, 12 6, and 12 8 consisted almost entirely of αp‐structure material, with only a trace of βp‐structure material being present. In contrast, nylons 10 6, 10 8, 10 10, 12 10, and 12 12 contained substantial quantities of both αp‐ and βp‐structure material, with αp‐structure material always being in the majority. Preparations of nylons 10 8, 12 10, and 12 12 also showed an additional diffraction signal at 0.42 nm; this signal is characteristic of the pseudohexagonal (high temperature) structure. The melting temperature of solution‐grown lamellae of these even‐even nylons decreases with decreasing linear amide density. On heating, the strong diffraction signals (0.44 nm and 0.37 nm) gradually moved together and merge at the Brill temperature to form a single diffraction signal (0.42 nm), characteristic of the pseudohexagonal structure. This single diffraction signal remained until melting. For nylons 6 6, 8 6, 8 8, 10 6, and 12 6, the Brill temperatures were substantially below the respective melting temperatures and the single 0.42 nm diffraction signal was stable over temperature ranges of 14 °C to 56 °C, depending on the nylon. Conversely, nylons 10 8, 10 10, 12 8, 12 10, and 12 12 had coincident melting and extrapolated Brill temperatures. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1209–1221, 2000  相似文献   

3.
In this paper, a first-principles study on the stability, electronic and magnetic properties of MRh12 (M = Rh, Fe, Co and Ni) clusters is performed. By optimizing the geometrical structure, we find that MRh12 clusters change from a perfect icosahedron to a distorted structure and have an obvious bond length contraction as compared with the corresponding bulk phase; FeRh12, CoRh12, and NiRh12 clusters are more energetically stable than the RhRh12 cluster. The effect of the impurity M on the density of states, valence band width, HOMO and LUMO for MRh12 clusters is not significant, but when the central Rh atom is substituted with M, the magnetic moment of MRh12 reduces dramatically. The Mulliken population analysis indicates that there are more charge transfers from other orbitals to Rh4d and M3d orbitals, and the spd hybrid effect in d orbitals of MRh12 clusters is stronger than that in the RhRh12 cluster. this situation means that the unpaired d electrons have more chance to be paired, and the magnetic moments of MRh12 clusters can be reduced reasonably.  相似文献   

4.
Bonding, vibrational and magnetic properties of the cage-like molecule C(24)O(12) are studied by DFT calculations. Infrared- and Raman-active vibrational frequencies of the cage-like molecule C(24)O(12) are assigned. Two (13)C and one (17)O nuclear magnetic resonance (NMR) spectral signals of the cage-like molecule C(24)O(12) are characterized. Heat of formation of the cage-like molecule C(24)O(12) is estimated. Compared to C(60) and the cage-like molecule C(24)O(12), only from the thermodynamic points of view, C(24)O(12) is more stable than C(60). Thus we believe that the cage-like molecule C(24)O(12) has sufficient stability to allow its experimental preparation. We proposed that it could be synthesized by using the condensation of molecules C(6)(OH)(6) and C(12)Cl(12). Since the symmetry of C(24)O(12) is D(6), it is a chiral molecule.  相似文献   

5.
Preparation and Crystal Structure of LnAl3Br12 (Ln = La, Ce, Pr, Nd, Sm, Gd) and Thermal Decomposition to LnBr3 LnAl3Br12 (Ln = La, Ce, Pr, Nd, Sm, Gd) was prepared in crystalline form for the first time. The crystal structures of LaAl3Br12, PrAl3Br12, and NdAl3Br12 were determined on single crystals by X-ray methods. The isotypic compounds crystallize with trigonal symmetry, space group P 3112, Z = 3. A structural comparison to lanthanoide chloroaluminates of equal composition is given and thermal decomposition of LnAl3Br12 (Ln = Nd) to the corresponding lanthanoide tribromide is described.  相似文献   

6.
The electronic structures and stabilities of cationic MPb12+ clusters (M = B, Al, Ga, In, and Tl) with 50 valence electrons are investigated within density functional theory. It is shown that, at the B3LYP/cc-pVDZ(-PP) and BPW91/cc-pVDZ(-PP) levels of theory, the structures of MPb12+ with icosahedra (I(h)) symmetry are energetically favorable, and their high stabilities may arise from the closed-shell nature of the pi subsystems which are subject to the 2(N(pi + 1)2 rule with N(pi = 1). In addition, the possessing of large nucleus-independent chemical shifts of the five kinds of clusters reflects the common aromatic character of these clusters. From the comparison of our studies on the binding energies and the highest occupied molecular orbital and the lowest unoccupied molecular orbital energy gaps, the cluster AlPb12+ has higher stability than the others and this is consistent with the recent mass-spectrometric discovery of Al-doped Pb(n)+ clusters, in which AlPb12+ is highly abundant. The same methods are used to search for the structures of the neutral MPb12 clusters. The calculations reveal that the most stable geometries of the BPb12 and GaPb12 clusters have I(h) symmetry, the AlPb12 and InPb12 clusters have T(h) symmetry, and the TlPb12 cluster has C5v symmetry. Furthermore, the vertical ionization potentials of the neutral MPb12 clusters are smaller than that of some alkali atoms, indicating that the neutral MPb12 clusters possess superalkali character.  相似文献   

7.
A series of thieno[2,3-d]pyrimidines were designed and synthesized as epidermal growth factor receptor (EGFR) inhibitors. These compounds were tested for their ability to inhibit MCF-7 and A549 cancer cells. The most active compound, 12c , inhibited the growth of both cell lines, with IC50 values of 15.67 and 12.16 μM, respectively. It was found that 12c had inhibitory effects on both EGFRWT and EGFRT790M isoforms, with inhibitory partialities of 37.50 and 148.90 nM, respectively. Additionally, 12c was found to be safer than erlotinib against normal cell lines (IC50 = 38.61 μM). Compound 12c induced early and late apoptosis in A549 cells and arrested cell growth at G1 and G2/M phases. 12c was also found to increase caspases 3 and 8 ratios. Molecular docking indicated the correct binding modes of the synthesized compounds. MD simulations, MM-GBSA, and PLIP studies confirmed the precise binding of 12c to the EGFR protein over 100 ns.  相似文献   

8.
采用基于密度泛函理论的第一性原理方法系统地研究了Au12M(M=Na,Mg,Al,Si,P,S,Cl)团簇的结构、稳定性和电子性质.对团簇的平均结合能、镶嵌能、垂直离化势、最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)的能级差、电荷布居分析、自然键轨道(NBO)进行了计算和讨论.对于Au12M(M=Na,Mg,Al)团簇,它们形成了内含M原子的最稳定的笼状结构.然而对于Au12M(M=Si,P,S,Cl)团簇,它们却形成了以M元素为顶点的稳定锥形结构.在这些团簇中发现Au12S团簇相对是最稳定的,这是由于Au12S团簇形成了稳定的满壳层的电子结构.自然电荷布居分析表明:对于所有的Au12M(M=Na,Mg,Al,Si,P,S,Cl)团簇电荷总是从Au原子转向M原子.自然键轨道和HOMO分析表明Au12M团簇中发生了Au原子的s-d轨道和M原子的p轨道间的杂化现象.  相似文献   

9.
The interfacial tension, wettability, foam and emulsification properties of di-tetrapropylene diphenyl ether disulfonates (C12-DADS) gemini-type surfactant have been studied and compared to mono-tetrapropylene diphenyl ether disulfonates (C12-MADS) and tetrapropylene benzene sulfonates (C12-BAS). The results show that the C12-DADS have a lower interfacial activity compared to that of C12-MADS and C12-BAS. The wettability of the three surfactants decreases in the order C12-BAS?>?C12-DADS?>?C12-MADS. For foam properties, the foamability and foam stability of C12-MADS and C12-DADS is lower than that of C12-BAS. In addition, the emulsification ability increase in the order C12-DADS?12-MADS?12-BAS.  相似文献   

10.
以双(2-羟基-3,5-二氯苯基)甲烷(4)与PSCl3关环,高收率地得到2,4,6,8,10-五氯-6-硫-12H-双苯并[d,g][1,3,2]二氧磷杂八环(5)。5与酚在无水K2CO3及铜粉存在下,或与醇在醇钠存在下反应,生成2,4,8,10-四氯-6-硫-6-芳氧基-12H-双苯并[1,3,2]二氧磷杂八环(6),或6-烷氧基的类似物(7)。5与醇在三乙胺存在下反应的产物为2,4,8,10-四氯-6-硫-6-羟基-12H-双苯并[1,3,2]二氧磷杂八环三乙胺盐(8)。8在DMSO中回流则氧化为它的氧类似物9。  相似文献   

11.
In order to find a new variety of ryanodine receptor(RyR) regulator with greater biological activity, a series of anthranilic diamide derivatives possessing pyrrole structure was designed and synthesized in this study. The pyrrole derivatives were evaluated for their insecticidal activity against Mythimna separata and Plutella xylostella. As indicated by the preliminary biological activities, compounds 12h-12j and 12l-12n exhibited a remarkable insecticidal activity against M. separata at 0.25 mg/L. Compared to control chlorantraniliprole, compound 12j exhibited more excellent insecticidal activity at 0.1 mg/L. Meanwhile, compounds 12c, 12h, 12i, 12j, 12l, and 12m were selected to test the insecticidal activity against P. xylostella, which led to the desirable insecticidal activity at 1×10-3 mg/L. Notably, compound 12l demonstrated 47% insecticidal activity at 5×10-6mg/L over the control. In addition, the biological mechanism of action of compound 12j was investigated by means of insect electrophysiology experiment.  相似文献   

12.
Tkachuk AV  Mar A 《Inorganic chemistry》2005,44(7):2272-2281
The rare-earth intermetallic compounds (RE)12Co5Bi (RE = Y, Gd, Tb, Dy, Ho, Er, Tm) were prepared by arc-melting and annealing at 600 degrees C. These compounds extend the previously known (RE)6M2+xX1-x (M = Co, Ni; X = Ga, In, Sn, Pb) series with the Ho6Co2Ga-type structure to X = Bi. The crystal structure of Ho12Co5Bi was refined by the Rietveld method from powder X-ray diffraction data obtained using synchrotron radiation (Pearson symbol oI36, orthorhombic, space group Immm, Z = 2, a = 9.37598(14) A, b = 9.37871(14) A, c = 9.85465(13) A). Unlike other Ho6Co2Ga-type compounds, the 2a site in Ho12Co5Bi is exclusively occupied by Co atoms. Four-probe electrical resistivity measurements on sintered polycrystalline samples of (RE)12Co5Bi indicated metallic behavior. Magnetic measurements revealed behavior ranging from frequency-dependent maxima in the ac susceptibility for Y12Co5Bi to possible ferrimagnetic ordering for Gd12Co5Bi to antiferromagnetic ordering with metamagnetic transitions for the remaining compounds. As confirmed by band structure calculations using Y12Co5Bi as a model compound, Y-Y and Y-Co interactions are the most important bonding components, but matrix effects are likely responsible for anomalously short Co-Co contacts in the structure.  相似文献   

13.
Russian Journal of General Chemistry - Clusters (Ih)-(Cd, Hg, Yb)@(Pb12, Sn12), (C5v)-(Ag, Au)@BiPb11, (C5v)-Ag@SbSn11, (D5d)(Ni, Pd, Pt)@Bi2Pb10, (D5d)-Pd@Sb2Sn10, (C3v)-(Pb12, Sn12)·(Pb, Sr,...  相似文献   

14.
Using the first-principles method with the generalized gradient approximation, the authors have studied the structural and electronic properties of Al(12)X(+) (X=C, Si, Ge, Sn, and Pb) clusters in detail. The ground state of Al(12)C(+) is a low symmetry C(s) structure instead of an icosahedron. However, the Si, Ge, Sn, and Pb atom doped cationic clusters favor icosahedral structures. The ground states for Al(12)Si(+) and Al(12)Ge(+) are icosahedra, while the C(5nu) structures optimized from an icosahedron with a vertex capped by a tetravalent atom have the highest binding energy for Al(12)Sn(+) and Al(12)Pb(+) clusters. The I(h) structure and the C(5nu) structure are almost degenerate for Al(12)Ge(+), whose binding energy difference is only 0.03 eV. The electronic properties are altered much by removing an electron from the neutral cluster. The binding strength of a valence electron is enhanced, while the binding energy of the cluster is reduced much. Due to the open electronic shell, the band gaps between the highest occupied molecular orbital and the lowest unoccupied molecular orbital are approximately 0.3 eV for the studied cationic clusters.  相似文献   

15.
Surface of mesocellular silica foam (MCF) was modified by grafting 3-aminopropyltriethoxysilane (APTES) to have the positive charge, and thus, to provide sites for the immobilization of H3PW12O40 (PW12). This modified-nanosized mesoporous silica (PW12-APTES@MCF) was characterized by FTIR, XRD, BET and TEM. The photoefficiency of this nanosized mesoporous toward photodegradation of six dye solutions [rhodamine B, malachite green, methylene blue, rose bengal, solophenyl red (3-BL), yellow direct 50 (CI-50)] was investigated in a photocatalytic reactor using UV lamp as a light source. The effect of various experimental parameters on the degradation performance of the process was evaluated by examining catalyst dosage, initial dye concentration and pH of the dye solution in the presence of PW12-APTES@MCF. The photocatalytic behaviors of the PW12-APTES@MCF were also compared with two mesoporous silica-supported PW12-APTES@SBA-15 and PW12-APTES@KIT-6. It indicated that the PW12-APTES@MCF had the highest photocatalytic efficiency among three mesoporous silica-supported PW12-APTES. These photocatalysts can be reused several times although they get less active.  相似文献   

16.
在合成(NH4)3PMo12O40和K3PMo12O40的基础上,用改进的方法合成了(NH4)3AsMo12O40和K3AsMo12O40,以FTIR、XRD、TG-DTA、ESR和TPR等手段对其结构、热稳定性和还原性进行了考查,当中心原子由P换成As后,杂多钼酸盐热稳定性下降,还原性提高.  相似文献   

17.
在研究闭式多面体(HAlNH)12簇合物几何构型及稳定性的基础上, 用DFT的B3LYP方法在6-31G(d)的水平上, 对其内含式复合物X@(HAlNH)12 (X= Be, Mg, Ca, Zn, Al+, Ga+)进行了构型优化和能量计算, 并讨论了稳定结构的几何构型、自然键轨道(NBO)、振动频率、能量参数及NMR数据与结构的关系. 用Gaussian 03的QST3方法确定了客体X通过笼面6-元环的迁移过渡态(TS)结构, 并用IRC方法对所得TS结构进行了验证. 最后得到内含式复合物X@(HAlNH)12结构在热力学和动力学上的稳定性信息, 其中复合物Ga+@(HAlNH)12的结构相对最稳定.  相似文献   

18.
The bis(phosphatediester)-bridged complexes [[Ni([12]aneN(3))(mu-O(2)P(OR)(2))](2)](PF(6))(2) [[12]aneN(3)=Me(3)[12]aneN(3), 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene; R=Me (1), Bu (2), Ph (3), Ph-4-NO(2) (4); [12]aneN(3)=Me(4)[12]aneN(3), 2,4,4,9-tetramethyl-1,5,9-triazacyclododec-1-ene; R=Me (5), Bu (6), Ph (7), Ph-4-NO(2) (8)] were prepared by hydrolysis of the phosphate triester with the hydroxo complex [[Ni([12]aneN(3))(mu-OH)](2)](PF(6))(2) or by acid-base reaction of the dialkyl or diaryl phosphoric acid and the above hydroxo complex. The acid-base reaction was also used to synthesise the phosphinate-bridged complexes [[Ni([12]aneN(3))(mu-O(2)PR(2))](2)](PF(6))(2) [[12]aneN(3)=Me(3)[12]aneN(3), R=Me (9), Ph (10); [12]aneN(3)=Me(4)[12]aneN(3), R=Me (11), Ph (12)]. The molecular structures of complexes 2, 3 and 12 were established by single crystal X-ray diffraction studies. The eight-membered rings defined by the nickel atoms and the bridging ligands show distorted twist-boat, chair and boat-boat conformations in 2, 3 and 12, respectively. The experimental susceptibility data for compounds 2, 3 and 12 were fitted by least-squares methods to the analytical expression given by Ginsberg. The best fit was obtained with values of J=-0.11 cm(-1), D=-9.5 cm(-1) and g=2.20 for 2; J=-0.97 cm(-1), D=-9.3 cm(-1) and g=2.21 for 3; and J=-0.14 cm(-1), D=-11.9 cm(-1) and g=2.195 for 12. The magnetic-exchange pathways must involve the phosphate/phosphinate bridges, because these favour antiferromagnetic interactions. The observation of a higher exchange parameter for compound 3 is a consequence of a favourable disposition of the O-P-O bridges. The kinetics for the hydrolysis of TNP (tris(4-nitrophenyl)phosphate) with the dinuclear nickel(II) hydroxo complex [[Ni(Me(3)[12]aneN(3))(mu-OH)](2)](PF(6))(2) was studied by UV-visible spectroscopy. The proposed mechanism for TNP-promoted hydrolysis can be described as one-substrate/two-product, and can be fitted to a Michaelis-Menten equation.  相似文献   

19.
The distribution ratios of two isomeric 5, 7, 7, 12, 12, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecane, tet c and tet d, in several solvent systems at 25.0°C as functions of hydrogen ion concentration were determined. The protonation constants and the distribution constants of these macrocyclic ligands and their protonated species were obtained from the variations of the distribution ratios in the range of 6<–log [H+]<14.  相似文献   

20.
The dynamics of the amphiphilic semifluorinated F(CF2)12(CH2)12H (F12H12) alkane that undergoes two condensed phase transitions have been investigated by Brillouin light spectroscopy, shear rheometry, small- (SAXS) and wide-angle (WAXS) X-ray scattering, and thermodynamic PVT measurements. The solid (I)-solid (II) transition (Ts) is marked by a stronger temperature dependence of the sound velocity in phase II and by a 2 orders of magnitude drop of the shear modulus. Between the Ts and the melting transition (Tm), the presence of two phonons implies a coexistence of solid (II) and amorphous (liquid) regions in the submicrometer range at thermal equilibrium as revealed by the SAXS pattern of a single reflection superimposed on a very broad amorphous halo. This intriguing finding of a transient, very slow (over 10 h) solid/liquid coexistence within phase II is rationalized by a two-stage mechanism for melting of the smectic phase (II) of F12H12. A refinement of the known packing motifs for the two solid-state structures is proposed.  相似文献   

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