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91.
The reactions of 2,2,2-trichloro-1-phenylethanone with various oxygen, carbon and sulfur nucleophiles were investigated with a view of widening the use of trichloroethanones as acylating agents. 相似文献
92.
Dihalocarbenes generated under phase transfer conditions add to cis and trans vinylic selenides to give the corresponding 1,1-dihalo-2-selenocyciopropanes with retention of configuration. 相似文献
93.
Joaquin Barbera Mercedes Marcos Ana Omenat Jose-Luis Serrano Jesus I. Martinez Pablo J. Alonso 《Liquid crystals》2013,40(2):255-262
The synthesis and liquid crystalline behaviour of the first and second generations of a dendrimeric structure based on poly(propyleneimine)(DAB-dendr(NH2)x) are reported. 4-(4-n-Alkoxybenzoyloxy)salicylaldehydes are used as mesogenic moieties attached at the peripheral amino groups of the dendrimers giving rise to dendromesogens with four and eight mesogenic branches. From these dendromesogens, considered as organic ligands, were prepared six metal-containing dendrimers which incorporate two or four copper atoms in their structures. All the dendrimeric ligands and three of the metal-containing dendrimers exhibit liquid crystalline properties which were studied by optical microscopy, DSC, X-ray diffraction and EPR spectroscopy. 相似文献
94.
Maria I. Z. Lionzo Edvani C. Muniz Nádya P. da Silveira 《Colloid and polymer science》2013,291(5):1057-1064
A composite multilamellar liposome containing chitosan attached to the inside and outside of the membrane as well as an opposite charged polyelectrolyte, chondroitin, adsorbed at the surface was developed. Not only the chitosan/chondroitin ratio but also the concentration of them were varied. The structure and superficial properties of the liposomes were studied through a combination of light scattering, zeta potential, and small-angle X-rays scattering techniques. While the chitosan/chondroitin ratio affected the superficial charge distributions, the concentration of polyelectrolytes affected the structural properties of the liposomes, as the rigidity of the phospholipid layers. The superficial charge of the resultant composite liposome was influenced by the type and concentration of the polyelectrolyte. Information about the charge density could be obtained by the treatment of zeta potential data, and it was used to estimate the amount of chondroitin adsorbed to the liposome surface. Applying the modified Caillé theory to the X-rays scattering curves, information about the internal structure of the liposomes was accessed. The ability to control the properties of composite multilamellar liposomes is an important issue when they have to be applied as a biomaterial device component. 相似文献
95.
Dr. Ángel J. Jiménez Michael Sekita Dr. Esmeralda Caballero Dr. M. Luisa Marcos Dr. M. Salomé Rodríguez‐Morgade Prof. Dr. Dirk M. Guldi Prof. Tomás Torres 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(43):14506-14514
In a novel electron‐donor–acceptor conjugate, phthalocyanine (Pc) and perylenediimide (PDI) are connected through a trans‐platinum(II) diacetylide linker to yield Pc‐Pt‐PDI 1 . In the ground state, the presence of PtII disrupts the electronic communication between the two electroactive components, as revealed by UV/Vis spectroscopy and electrochemical studies. The photophysical behavior of 1 is compared with that of the corresponding Pc‐PDI electron‐donor–acceptor conjugate 2 in terms of charge separation and charge recombination. The insertion of PtII between Pc and PDI impacts the results in a longer‐lived Pc . +/PDI . ? radical ion‐pair state. In addition, the intermediately formed Pc triplet excited state is formed with higher quantum yields in 1 than in 2 . 相似文献
96.
Cristina Alvariño Dr. Elena Pía Prof. Marcos D. García Dr. Víctor Blanco Prof. Alberto Fernández Prof. Carlos Peinador Prof. José M. Quintela 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(45):15329-15335
A family of PdII/PtII dinuclear receptors, designed to give a smooth increase in their cavity lengths (from 7.46–13.78 Å), is presented. Their inclusion complexes with a representative set of polycyclic aromatic substrates (naphthalene, carbazol, pyrene, and benzo[a]pyrene), were characterized and studied in aqueous solution and the solid state. By taking into account the dimensions of both receptors and substrates, an excellent complementarity was found between the size of the receptors and their ability to complex a given substrate. Furthermore, this dimensional matching results in specific binding modes depending on the ability of the guest to establish stabilizing [C? H???π] interactions with the host. 相似文献
97.
Núria Mas Alessandro Agostini Dr. Laura Mondragón Dr. Andrea Bernardos Dr. Félix Sancenón Dr. M. Dolores Marcos Prof. Ramón Martínez‐Máñez Prof. Ana M. Costero Prof. Salvador Gil Prof. Matilde Merino‐Sanjuán Prof. Pedro Amorós Dr. Mar Orzáez Prof. Enrique Pérez‐Payá 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(4):1346-1356
The preparation of a new capped silica mesoporous material, Rh‐Azo‐S , for on‐command delivery applications in the presence of target enzymes is described. The material consists of nanometric mesoporous MCM‐41‐like supports loaded with Rhodamine B and capped with an azopyridine derivative. The material was designed to show “zero delivery” and to display a cargo release in the presence of reductases and esterases, which are usually present in the colon, mainly due to intestinal microflora. The opening and cargo release of Rh‐Azo‐S in vitro studies were assessed and seen to occur in the presence of these enzymes, whereas no delivery was noted in the presence of pepsine. Moreover, Rh‐Azo‐S nanoparticles were used to study controlled Rhodamine B dye delivery in intracellular media. HeLa cells were employed for testing the “non”‐toxicity of nanoparticles. Moreover, delivery of the dye in these cells, through internalization and enzyme‐mediated gate opening, was confirmed by confocal microscopy. Furthermore, the nanoparticles capped with the Azo group and loaded with a cytotoxic camptothecin ( CPT ) were also prepared (solid CPT‐Azo‐S ) and used as delivery nanodevices in HeLa cells. When this solid was employed, the cell viability decreased significantly due to internalization of the nanoparticles and delivery of the cytotoxic agent. 相似文献
98.
99.
A concise, two-step eco-friendly approach towards the synthesis of 5-sulfenyl tetrazole derivatives of indoles and pyrroles, is reported. The synthesis comprises the oxone-mediated thiocyanation of the starting heterocycles towards intermediate 3-thiocyanato indoles and 2-thiocyanato pyrroles, and their subsequent treatment with sodium azide in 2-propanol/water under zinc bromide promotion. 相似文献
100.
Amanda S. Santana Diego B. Carvalho Nadla S. Cassemiro Luiz H. Viana Gabriela R. Hurtado Marcos S. Amaral Najla M. Kassab Palimécio G. Guerrero Jr. Sandro L. Barbosa Miguel J. Dabdoub Adriano C.M. Baroni 《Tetrahedron letters》2014
A simple synthesis of 3-iodothiophenes was demonstrated using a wide range of (Z)-thioenynes. The key step in the iodocyclofunctionalization was the selective reduction of the triple bond in (Z)-thioenynes by the addition of iodine as an electrophilic agent. The 3-iodothiophenes were obtained in good to excellent yields of 61–92%. The 3-iodothiophenes were used as substrates in Sonogashira cross-coupling reactions to obtain thiophene acetylenes. 相似文献