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61.
A simplified synthesis of a previously reported Cd2Cu2 complex 4 was developed in order to have a more readily available source of 1,3,5-tris(trifluoromethyl)-cyclohexane-cis,cis-1,3,5-triol 1, a unique tridentate ligand, only tentatively identified elsewhere. Attempts to liberate the ligand from 4 resulted in the sole formation of 2,4,6-tris(trifluoromethyl)-tetrahydropyran-cis,cis-2,4,6-triol (2); no traces of 1 were detected. A newly conducted X-ray analysis of complex 4 led to diffraction data that could be explained either by the previously reported structure for 4 or by the statistically disordered structure 5, containing ligand 2 rather than 1. Whereas refinement of both models led to equivalent merit factors, mass spectral data and elemental analysis of the crystals revealed unequivocally the sole presence of the tetrahydropyran derivative within the complex and proved thus the erroneous structure assignment 4 previously published for compound 5. 相似文献
62.
Tetrazine Click Chemistry for the Modification of 1‐Hydroxy‐1,1‐methylenebisphosphonic Acids: Towards Bio‐orthogonal Functionalization of Gold Nanoparticles
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Romain Aufaure Dr. Julie Hardouin Prof. Nadine Millot Prof. Laurence Motte Dr. Yoann Lalatonne Dr. Erwann Guénin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(45):16022-16027
Inverse electron demand Diels–Alder (iEDDA) was evaluated for the functionalization of gold nanoparticles. The reaction was first modelled with the free coating molecule 1‐hydroxy‐1,1‐methylenebisphosphonate bearing an alkene functionality (HMBPene). A model tetrazine 3,6‐dipyridin‐2‐yl‐1,2,4,5‐tetrazine (pyTz) was used, kinetic of the reaction was calculated and coupling products were analysed by NMR and HRMS. The reaction was then transposed at the nanoparticle surface. Gold nanoparticles bearing an alkene functionality were obtained using a one‐pot methodology with HMBPene and the tetrazine click chemistry was evaluated at their surface using pyTz. The successful coupling was assessed by XPS measurements. This click‐methodology was extended to the conjugation of a NIR probe at the NP surface. 相似文献
63.
Ufuk Kumru Fabienne Dumoulin Erwann Jeanneau Fatma Yuksel Yari Cabezas Yunus Zorlu Vefa Ahsen 《Structural chemistry》2012,23(1):175-183
Three tert-butylsulfanylphthalonitriles have been prepared with optimized synthetic procedures. Their comparative structural analyses
have been completed, with a focus on IR and NMR spectroscopy and refined X-ray structural data. Miscellaneous parameters such
as UV absorption, melting points, and related polarity of the compounds are summarized. 相似文献
64.
65.
Iasco O Novitchi G Jeanneau E Tommasino JB Roques N Luneau D 《Inorganic chemistry》2012,51(4):2588-2596
Two benzoxazoles derivative ligands were synthesized from the condensation of 3,5-di-tert-butyl-o-benzoquinone (DTBBQ) with ethanolamine or 1,3-diamino-2-hydroxypropane in methanol. Condensation of DTBBQ with ethanolamine gives the expected 5,7-di-tert-butyl-2-methylenhydroxylbenzoxazole (HL1) while with 1,3-diamino-2-hydroxypropane it gives (2-hydroxyethyl-2-{2,4-bis(1,1-dimethylethyl)-1-phenol-6 amino}-2{5,7-di-tert-butyl-benzoxazole}) (H(2)L2) with only one benzoxazole ring instead of the symmetric bis-benzoxazole derivative. The structure of HL1 and H(2)L2 were confirmed by NMR-spectroscopy and X-ray diffraction on a single crystal for HL1. The reaction of HL1 with CuCl(2) gives a mononuclear [Cu(II)(HL1)(2)Cl(2)] (1) complex for which the crystal structure shows that HL1 is preserved. In contrast, upon reaction with nickel(II), cobalt(II), and manganese(II) H(2)L2 is further oxidized and transformed in new ligands HL3 in mononuclear complexes [M(II)(L3)(2)] (M = Ni(II) (2); M = Co(II) (3)) and H(2)L4 in tetranuclear complex [Mn(II)(4)(HL4)(4)Cl(4)] (4) as found from the crystal structures of complexes 2-4. Electrochemical studies for complexes 2 and 3 evidence complicated redox properties. [Mn(II)(4)(HL4)(4)Cl(4)] (4) has a cubane-like structure with a "4 + 2" fashion The magnetic susceptibility of 4 is well fitted considering one Mn---Mn interaction J(a)(Mn(II)-Mn(II)) = -0.50(1) cm(-1) with g = 2.00(7). 相似文献
66.
1,1,1‐Trimethylhydrazinium iodide ([(CH3)3N? NH2]I, 1 ) was reacted with a silver salt to form the corresponding nitrate ([(CH3)3N? NH2][NO3], 2 ), perchlorate ([(CH3)3N? NH2][ClO4], 3 ), azide ([(CH3)3N? NH2][N3], 4 ), 5‐amino‐1H‐tetrazolate ([(CH3)3N? NH2][H2N? CN4], 5 ), and sulfate ([(CH3)3N? NH2]2[SO4]?2H2O, 6 ?2H2O) salts. The metathesis reaction of compound 6 ?2H2O with barium salts led to the formation of the corresponding picrate ([(CH3)3N? NH2][(NO2)3Ph ‐ O], 7 ), dinitramide ([(CH3)3N? NH2][N(NO2)2], 8 ), 5‐nitrotetrazolate ([(CH3)3N? NH2][O2N? CN4], 9 ), and nitroformiate ([(CH3)3N? NH2][C(NO2)3], 10 ) salts. Compounds 1 – 10 were characterized by elemental analysis, mass spectrometry, infrared/Raman spectroscopy, and multinuclear NMR spectroscopy (1H, 13C, and 15N). Additionally, compounds 1 , 6 , and 7 were also characterized by low‐temperature X‐ray diffraction techniques (XRD). Ba(NH4)(NT)3 (NT=5‐nitrotetrazole anion) was accidentally obtained during the synthesis of the 5‐nitrotetrazole salt 9 and was also characterized by low‐temperature XRD. Furthermore, the structure of the [(CH3)3N? NH2]+ cation was optimized using the B3LYP method and used to calculate its vibrational frequencies, NBO charges, and electronic energy. Differential scanning calorimetry (DSC) was used to assess the thermal stabilities of salts 2 – 5 and 7 – 10 , and the sensitivities of the materials towards classical stimuli were estimated by submitting the compounds to standard (BAM) tests. Lastly, we computed the performance parameters (detonation pressures/velocities and specific impulses) and the decomposition gases of compounds 2 – 5 and 7 – 10 and those of their oxygen‐balanced mixtures with an oxidizer. 相似文献
67.
Sabaté CM Jeanneau E Delalu H 《Dalton transactions (Cambridge, England : 2003)》2012,41(13):3817-3825
Diaminomaleodinitrile was reacted at low temperatures with in situ generated nitrous acid to form 4,5-dicyano-2H-1,2,3-triazole (1) in yields above 90%. Crystalline 1 was then reacted with one equivalent of a suitable alkali or alkaline earth metal base (typically a hydroxide or a carbonate) in a polar solvent to form the corresponding alkali and alkaline earth metal salts of 4,5-dicyano-2H-1,2,3-triazole (compounds 2-9). The thermal stability of the metal salts 2-9 was assessed by differential scanning calorimetry, which showed excellent thermal stabilities up to above 350 °C. Due to the energetic character of triazole-based salts, initial safety testing was used to assess the sensitivity of compounds 2-9 towards impact, friction, electrostatic discharge and fast heating. These results revealed very low sensitivities towards all four stimuli. Additionally, compounds 2-9 were characterized by mass spectrometry, elemental analysis, infrared and Raman spectroscopy and ((1)H, (13)C and (14)N) NMR spectroscopy. We also determined the solid state structure of the 4,5-dicyano-2H-1,2,3-triazole anion of one of the alkali metal salts (4: Monoclinic, P2(1)/c, a = 9.389(1) ?, b = 10.603(1) ?, c = 6.924(1) ?, β = 102.75(1)° and V = 1036.58(3) ?(3)) and one of the alkaline earth metal salts (6: Monoclinic, P2(1)/c, a = 9.243(1) ?, b = 15.828(2) ?, c = 6.463(1) ?, β = 90.23(1)° and V = 945.5(2) ?(3)). Furthermore, we noted the hydrolysis of one of the cyano groups of the 4,5-dicyano-2H-1,2,3-triazole anion in the strontium salt 8 to form the 5-cyano-2H-1,2,3-triazole-4-carboxylic acid derivative 8b, as confirmed by X-ray studies (8b: Monoclinic, P2(1)/n, a = 6.950(1) ?, b = 17.769(1) ?, c = 13.858(1) ?, β = 92.98(1)° and V = 1709.1(1) ?(3)). Lastly, we computed the NBO and Mülliken charges for the anion of compounds 2-9 and those of the anion of compound 8b. 相似文献
68.
We first show that the connected sum along submanifolds introduced by the second author for compact initial data sets of the vacuum Einstein system can be adapted to the asymptotically Euclidean and to the asymptotically hyperbolic context. Then, we prove that in every case, and generically, the gluing procedure can be localized, in order to obtain new solutions which coincide with the original ones outside of a neighborhood of the gluing locus. 相似文献
69.
Abstract The melting curve of NaCl0.5Br0.5 has been measured under pressure up to 4.5 GPa. The melting temperatures of Ag and NaCl have been used to determine the pressure in the sample at its melting temperature. 相似文献
70.
Erwann Delay 《偏微分方程通讯》2013,38(10):1689-1716
We give sufficient conditions for some underdetermined elliptic PDE of any order to construct smooth compactly supported solutions. In particular we show that two smooth elements in the kernel of certain underdetermined linear elliptic operators P can be glued in a chosen region in order to obtain a new smooth solution. This new solution is exactly equal to the initial elements outside the gluing region. This result completely contrasts with the usual unique continuation for determined or overdetermined elliptic operators. As a corollary we obtain compactly supported solutions in the kernel of P and also solutions vanishing in a chosen relatively compact open region. We apply the result for natural geometric and physics contexts such as divergence free fields or TT-tensors. 相似文献