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991.
De‐Hong Wu Cheng He Chun‐Ying Duan Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1336-1337
The thiosemicarbazone molecule in C10H12N6S2·2C3H7NO has symmetry. The thiosemicarbazone moiety and the benzene ring are essentially coplanar, with mean and maximum deviations of 0.03 and 0.11 Å, respectively. The dimethylformamide molecules bridge the thiosemicarbazone moieties, forming two‐dimensional sheets through N—H?O hydrogen bonds. 相似文献
992.
Joo Hyun Kim Nam‐Ho You Hoosung Lee 《Journal of polymer science. Part A, Polymer chemistry》2006,44(12):3729-3737
A series of statistical copolymers (poly[(9,9‐di‐n‐hexylfluorene)‐co‐2‐{2,6‐bis‐[2‐(4‐diphenylaminophenyl)vinyl]pyran‐4‐ylidene}malononitrile) were synthesized by the Suzuki coupling reaction. The copolymers showed absorption bands at 379 and 483–489 nm, which were attributed to the oligofluorene segments and the segments containing 2‐[2,6‐bis(2‐{4‐[(4‐bromophenyl)phenylamino]phenyl}vinyl)pyran‐4‐ylidene]malononitrile ( 3 ), respectively. The absorption band around 483–489 nm increased with the feed ratio of 3 . The photoluminescence (PL) spectra of the copolymers showed emission bands at 420 and 573–620 nm. As the feed ratio of 3 increased, the PL emission in the longer wavelength region redshifted, and the intensity increased as well. The electroluminescence (EL) spectrum of the copolymers showed a very weak emission at 420 nm. The PL and EL emission colors redshifted dramatically with the increase in the feed ratio of 3 . The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of the model compound (2‐{2,6‐bis[2‐(4‐diphenylaminophenyl)vinyl]pyran‐4‐ylidene}malononitrile) were determined to be ?5.34 and ?3.14 eV, respectively. It was concluded that energy transfer took place from the oligofluorene blocks to the segments containing 3 and that direct charge trapping occurred in the segments containing 3 during the EL operation. The Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of the copolymer (x = 0.63, y = 0.37) containing 10 mol % 3 were very close to those (x = 0.67, y = 0.33) for National Television System Committee (NTSC) red with a maximum photometric power efficiency of 0.27 cd/A. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3729–3737, 2006 相似文献
993.
The monomeric octa-aza bis-α-diimine macrocyclic complex [CoII(C10H20N8)(H2O)](ClO4)2 I, undergoes various reactions on the macrocyclic ligand. Reaction of complex I with triethylamine in double molar proportions, followed by slow aerial oxidation, produces a molecular dimeric complex [CoII(C10H14N8)]2, III, and a novel Co(I) complex [CoI(C10H19N8)], IV. Complex III is a staggered cofacial dimer with a cobalt-cobalt bond length 2.86(1) Å. The macrocyclic ligand of the complex contains an a-diimine function in each five-membered chelate ring, and a three-atom N-C-N? delocalized system in each six-membered chelate ring. Complex IV has the 5-5-6-6 chelate arrangement because one α-diimine moiety is rearranged to a syn-anti configuration. In the structure, the two fused six-membered chelate rings are fully conjugated and the two fused five-membered rings are saturated. However, when complex I reacts with excess triethylamine under the similar conditions, a dimeric complex of another type, [CoII(C10Hl6N8)]2, II, was generated, in which one N-N bond of the macrocyclic ligand is broken. Complex IV can be isolated also from the reaction of complex I with excess hydrazine, followed by slow aerial oxidation. When hydrazine in double molar proportions was used, complex [CoI(C10H17N8)(NHNH)] V, which contains a coordinated diazene ligand, was obtained. Only one six-membered chelate ring of complex V is deprotonated and oxidized to form a three-atom N-C-N? delocalized system. The structures of octa-aza complexes I-V are determined by X-ray crystallography: I, orthorhombic, C mca, a = 11.646(4), b = 17.049(3), c = 10.706(3) Å, Z = 4, R = 0.045, Rw = 0.047, based on 1024 reflections with I > 2σ(I); II, monoclinic, P 21/c, a = 9.814(3), b = 22.583(6). c = 14.632(9) Å, β = 98.90(5)°, Z = 4, R = 0.085, Rw = 0.101, based on 2033 reflections with I > 2σ(I); III, tetragonal, P 4/nmm, a = 15.614(3), c = 6.498(2) Å, Z = 4, R = 0.081, Rw = 0.115, based on 340 reflections with I > 2σ(I); IV, orthorhombic, P bca, a = 8.484(1), b = 16.662(3), c = 18.760(2) Å, Z = 8, R = 0.029, Rw = 0.024, based on 1441 reflections with I > 2σ(I); V, monoclinic, P 21/m, a = 7.892(3), b = 11.713(6), c = 9.326(4) Å, β = 108.03(3), Z = 2, R = 0.047, Rw = 0.056, based on 948 reflections with I > 2σ(I). 相似文献
994.
The diorganotin(Ⅳ) complexes of N-(3,5-dibromosalicylidene)-α-amino acid, R2Sn(2-O-3,5-Br2C6H2CH= NCHRCOO)(where R=H, Me, i-Pr, Bz; R'=n-Bu, Cy), were synthesized by the reactions of diorganotin dichlorides with in situ formed potassium salt of N-(3,5-dibromosalicylidene)-α-amino acid and characterized by elemental analysis, IR and NMR (^1H, ^13C and ^119Sn) spectra. The crystal structures of n-Bu2Sn(2-O-3,5-Br2C6H2CH= NCHRCOO)(R=i-Pr, Bz) and Cy2Sn(2-O-3,5-Br2C6H2CH=NCHRCOO)(R=Me, Bz) were determined by X-ray single crystal diffraction and showed that the tin atoms are in a distorted trigonal bipyramidal geometry to form five- and six-membered chelate rings with the tridentate ligand. Bioassay results indicated that the compounds possess better in vitro antitumour activity against three human tumour cell lines, HeLa, CoLo205 and MCF-7, than cis-platin and moderate anti-bacterial activity against two bacteria, E. coli and S. aureus. 相似文献
995.
996.
Qing Feng JIANG You Jun ZHOU Jian Zhong YAO Jia Guo LU Ju ZHU Chun Quan SHENG Can Hui ZHENG Bing YAO 《中国化学快报》2006,17(8):995-998
Since George R. Pettit’s group isolated cycloheptapeptide phakellistatin 1 from sponge1, over ten similar cyclic peptides have been obtained2-5. Phakellistatin 134 (Figure 1) is a cycloheptapeptide isolated from the brown snubby sponge from the South Chi… 相似文献
997.
998.
Joerg Freitag You Yokoyama Hidetoshi Kuramochi Katsuya Kawamoto Kunio Nagahama Satoru Kato 《Fluid Phase Equilibria》2007
The solubilities of phenylalanine and tyrosine in supercritical carbon dioxide (SCCO2) were measured after derivatization as the N-acetyl amino acid ethyl ester, N-carbobenzoxy amino acid and N-acetyl amino acid. Using an SCCO2 flow system, a measuring method of the saturated solubilities of the derivatized amino acids was established in which the contact height of the extraction cell, i.e. a packed column, is increased till the concentration of a derivatized amino acid at the exit of the cell reaches a plateau. The solubilities of N-acetyl phenylalanine ethyl ester (APEE) exceeded 0.001 mole fraction, which is higher than those of caffeine produced in industrial SCCO2 processes. A possible way of separating the amino acid mixtures using polarity differences in different amino acid side chains was demonstrated using the solubility data of the N-acetyl-amino acid ethyl esters in SCCO2, as the solubilities of APEE are higher than those of N-acetyl tyrosine ethyl ester by two orders of magnitude. 相似文献
999.
Leeuwenburgh MA Litjens RE Codee JD Overkleeft HS van der Marel GA van Boom JH 《Organic letters》2000,2(9):1275-1277
[formula: see text] Tributyltin radical mediated cyclization of carbohydrate-derived beta-(alkynyloxy)acrylates leading to highly functionalized cis- and trans-fused bicyclic ethers of various ring sizes is described. The efficacy of the radical cyclization is nicely illustrated in the iterative construction of a trans-fused tricyclic tetrahydropyran. 相似文献
1000.
A novel coordination polymer, [Ag4ppdc)(H2bpdc)(Hbpdc)2] (bpdc = 2,2′‐bipyridyl‐3,3′‐dicarboxylate), was hydrothermally synthesized at 403 K and structurally characterized by single crystal X‐ray diffraction analysis. The compound crystalizes in the monoclinic space group C2/c with a=1.9516(4) nm, b=1.9503(4) nm. c=1.2566(3) nm, and β=112.48(3)°. In the two‐dimensional crystal structure, AgI center is coordinated, in a scarce coordination environment, double‐capped tetrahedron, by one bpdc ligand to form N‐Ag‐N chelate bond via two pyridyl N atoms, and other two bpdc ligands to form two O‐Ag‐O chelate bonds, respectively, via two carboxyl O atoms. The bpdc ligands are present in one non‐protonated form, bpdc, and two protonated forms, Hbpdc and H2bpdc, which all act as μ3‐ligand in a hexadentate fashion (N, N′; O, O′; O, O′) to coordinate with three Ag centers, respectively, through the three chelate bonds. This coordinated fashion of bpdc ligand is first found in the title compound. W‐Us‐NIR reflectance spectroscopy study revealed insulator nature for the crystal with an optical energy gap of 3.1 eV. 相似文献