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1.
Earlier we noted that the hydroboration of the trimethylsilyl enol ether of an acyclic ketone results in an elimination of a trimethylsiloxyborane moiety with the subsequent formation of an olefin.1,2 The olefin formed then undergoes hydroboration giving a monoalcohol upon oxidation. (eq 1) We wish to report here on the utility of this sequence, illustrated in eq 1, in the reductive 1,2 transposition of acyclic ketones.3 相似文献
2.
Myriam E. Rodríguez Cristian A. Strassert Josefina Awruch Lelia E. Dicelio 《Journal of heterocyclic chemistry》2001,38(2):387-389
The synthesis of tetramethyl‐tetraphthalimidomethyl‐phthalocyaninato zinc(II) ( 6 ) and tetramethyl‐tetraaminomethyl‐phthalocyaninato zinc(II) ( 7 ) is described. 相似文献
3.
Koech PK Polikarpov E Rainbolt JE Cosimbescu L Swensen JS Von Ruden AL Padmaperuma AB 《Organic letters》2010,12(23):5534-5537
We studied the influence of a pyridine moiety versus a phenyl moiety when introduced in the molecular design of an ambipolar host. These pyridine-based host materials for organic light-emitting diodes (OLEDs) were synthesized in three to five steps from commercially available starting materials. The isomeric hosts have similar HOMO/LUMO energies; however, data from OLEDs fabricated using the above host materials demonstrate that small structural modification of the host results in significant changes in its carrier-transporting characteristics. 相似文献
4.
Yong-X. Hu David Winker Ping Yang Bryan Baum Lamont Poole Lelia Vann 《Journal of Quantitative Spectroscopy & Radiative Transfer》2001,70(4-6):569-579
A fast Monte Carlo simulation scheme is developed to assess the impact of multiple scattering on space-based lidar backscattering depolarization measurements. The specific application of our methodology is to determine cloud thermodynamic phase from satellite-based lidar depolarization measurements. Model results indicate that multiple scattering significantly depolarizes backscatter return from water clouds. Multiple scattering depolarization is less significant for non-spherical particles. There are sharp contrasts in the depolarization profile between a layer of spherical particles and a layer of non-spherical particles. Although it is not as obvious as ground-based lidar observations, it is likely that we can identify cloud phase not only for a uniform cloud layer, but also for overlapping cloud layers where one layer contains ice and the other water droplets. 相似文献
5.
Radical Compatibility with Nonaqueous Electrolytes and Its Impact on an All‐Organic Redox Flow Battery 下载免费PDF全文
Dr. Xiaoliang Wei Dr. Wu Xu Dr. Jinhua Huang Dr. Lu Zhang Dr. Eric Walter Dr. Chad Lawrence Dr. M. Vijayakumar Dr. Wesley A. Henderson Dr. Tianbiao Liu Dr. Lelia Cosimbescu Dr. Bin Li Dr. Vincent Sprenkle Dr. Wei Wang 《Angewandte Chemie (International ed. in English)》2015,54(30):8684-8687
Nonaqueous redox flow batteries hold the promise of achieving higher energy density because of the broader voltage window than aqueous systems, but their current performance is limited by low redox material concentration, cell efficiency, cycling stability, and current density. We report a new nonaqueous all‐organic flow battery based on high concentrations of redox materials, which shows significant, comprehensive improvement in flow battery performance. A mechanistic electron spin resonance study reveals that the choice of supporting electrolytes greatly affects the chemical stability of the charged radical species especially the negative side radical anion, which dominates the cycling stability of these flow cells. This finding not only increases our fundamental understanding of performance degradation in flow batteries using radical‐based redox species, but also offers insights toward rational electrolyte optimization for improving the cycling stability of these flow batteries. 相似文献
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7.
Myriam E. Rodriguez Virginia E. Diz Josefina Awruch Lelia E. Dicelio 《Photochemistry and photobiology》2010,86(3):513-519
The photophysical properties of lipophilic phthalocyanines encapsulated into a polymer and two different gels were studied in order to predict their photosensitizing efficacy in vivo. Photophysical techniques for solid phase were adapted for light dispersing samples. Gel formulation of two tetrasubstituted phthalocyanines, tetra-t-butylphthalocyaninato zinc(II) ( 1 ), tetrakis(1,1-dimethyl-2-phthalimido)ethylphtalocyaninatozinc(II) ( 2 ) and two octasubstituted phthalocyanines, 2,3,9,10,16,17,23,24-octakis(decyloxy)phthalocyaninatozinc(II) ( 3 ) and 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylamino)ethylsulfanyl]phthalocyaninatozinc(II) ( 4 ) were investigated for their possible use in photodynamic therapy for topical purposes. Supporting the fact that gel formulation improves the photophysical properties of phthalocyanines, singlet molecular oxygen quantum yield (ΦΔ) values for 1 – 4 zinc(II) phthalocyaninates in Lutrol® F 127-Cremophor® RH 40 were 0.60, 0.60, 0.20 and 0.26, respectively. Permeation studies showed that no release of phthalocyanines occurs, thus indicating there should be no risk of generalized skin photosensitivity in areas other than the dye-deposition site. 相似文献
8.
Liana Marta Lelia Ciontea T. Petrisor Maria Zaharescu D. Crisan Iovanca Haiduc 《Journal of Sol-Gel Science and Technology》1994,2(1-3):437-441
Bismuth high T
c superconducting oxide compounds were obtained by sol-gel method using acetate precursors. A study of the decomposition of quasi-amorphous acetates has been carried out to establish the conditions of superconducting phase formation. A comparison of the acetate sol-gel route with the oxalate coprecipitation method (previously used by the authors) reveals comparable results. Both methods require much shorter periods of thermal treatment for the formation of superconducting phases, as compared with the solid state reactions. The sol-gel route leads to better results from this point of view. 相似文献
9.
Caneschi A Dei A Mussari CP Shultz DA Sorace L Vostrikova KE 《Inorganic chemistry》2002,41(5):1086-1092
The tris-bidentate ligand 1,3,5-tris(5'-tert-butyl-3',4'-dihydroxyphenyl)benzene ((TBCat)(3)Ph) was synthesized. The reaction of this molecule in basic solution with two paramagnetic acceptors, i.e., a nickel(II)minus signtetraazamacrocyclic ligand complex (Ni(CTH)) (CTH = dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) and manganese(II)-hydrotris[3-(4'-cumenyl)-5-methylpyrazolyl]borate (Mn(Tp(Cum,Me))), yielded two complexes whose analytical formulas are consistent with those of trinuclear complexes. Spectroscopic and magnetic measurements suggest that these derivatives contain divalent metal ions coordinated to the tris(semiquinone) form of the ligand. Analysis of the magnetic data shows that the pi-connectivity of the ligand enforces ferromagnetic coupling between the three semiquinone units of the molecule, giving rise to complexes with S = 9/2 (M = Ni(II)) and S = 6 (M = Mn(II)) ground states. The coupling within the tris(semiquinone) unit is quite large (J = -26 cm(-1) for the nickel(II) derivative and J = -40 cm(-1) for the manganese(II) one, using the general exchange Hamiltonian H = sigma J(ij)S(i)S(j)), and it is of the same order of magnitude as that observed in an analogous series of bis(semiquinone) complexes that we recently reported. 相似文献
10.
Daniel A. Fernández Josefina Awruch Lelia E. Dicelio 《Photochemistry and photobiology》1996,63(6):784-792
Three potential photosensitizers for photodynamic therapy: tetra- t -butyl phthalocyaninato Zn(II), tetrakis-(1,1-dimethyl-2-phthalimido)ethylphthalocyaninato Zn(II), and tetrakis-(1,1-dimethyl-2-amino)ethylphthalocyaninato Zn(II), have been studied in homogeneous organic media. Dimerization constants and monomer and dimer spectra have been determined. Fluorescence, triplet and singlet oxygen quantum yìelds were measured and the photo-physical characterization of the triplet state was performed for the three dyes. These parameters were evaluated in connection with aggregation results. 相似文献