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91.
Ruiz J Lorenzo J Vicente C López G María López-de-Luzuriaga J Monge M Avilés FX Bautista D Moreno V Laguna A 《Inorganic chemistry》2008,47(15):6990-7001
The new complexes [Pd(dmba)( N10-9AA)(PPh 3)]ClO 4 ( 1), [Pt(dmba)( N9-9AA)(PPh 3)]ClO 4 ( 2), [Pd(dmba)( N10-9AA)Cl] ( 3), and [Pd(C 6F 5)( N10-9AA)(PPh 3)Cl] ( 4) (9-AA = 9-aminoacridine; dmba = N,C-chelating 2-(dimethylaminomethyl)phenyl) have been prepared. The crystal structures have been established by X-ray diffraction. In complex 2, an anagostic C-H...Pt interaction is observed. All complexes are luminescent in the solid state at room temperature, showing important differences between the palladium and platinum complexes. Complex 2 shows two structured emission bands at high and low energies in the solid state, and the lifetimes are in agreement with excited states of triplet parentage. Density functional theory and time-dependent density functional theory calculations for complex 2 have been done. Values of IC 50 were also calculated for the new complexes 1- 4 against the tumor cell line HL-60. All of the new complexes were more active than cisplatin (up to 30-fold in some cases). The DNA adduct formation of the new complexes synthesized was followed by circular dichroism and electrophoretic mobility. Atomic force microscopy images of the modifications caused by the complexes on plasmid DNA pB R322 were also obtained. 相似文献
92.
Reaction of [Au2(dppm)Cl2] with AgOTf in CH2Cl2 medium followed ligand addition and leads to [Au2(dppm)(RaaiR′)](OTf) [RaaiR′ = p-R–C6H4–N = N–C3H2–NN–1–R′, (1–3), abbreviated as N,N′-chelator, where N(imidazole) and N(azo) represent N and N′, respectively; R = H (a), Me (b), Cl (c) and R′ = Me (1), CH2CH3
(2), CH2Ph (3), OSO2CF3 is the triflate anion, and dppm is the diphenylphosphinomethane-ring]. The 1H-n.m.r. spectral measurements suggest methylene, –CH2–, in RaaiEt gives a complex AB type multiplet while in RaaiCH2Ph it shows AB type quartets with coupling constant of avg. 6 Hz. Considering all the moities there are a lot of different
carbon atoms in the molecule which gives a lot of different peaks in the 13C-n.m.r spectrum. In the 1H–1H-COSY spectrum of the present complexes and contour peaks in the 1H–13C-HMQC spectrum in the present complexes, assign the solution structure and stereoretentive transformation in each step. 相似文献
93.
Lardiés N Romeo I Cerrada E Laguna M Skabara PJ 《Dalton transactions (Cambridge, England : 2003)》2007,(45):5329-5338
A series of alkynethiolate gold(I) derivatives have been synthesised by the cleavage of 4-monosubstituted 1,2,3-thiadiazoles in the presence of strong bases. The syntheses of the 1.2,3-thiadiazoles with p-cyanophenyl, p-tolyl, 2-thienyl, 3-thienyl and 9,9-dimethylfluoren-2-yl fragments are also described. All the complexes have been characterised by spectroscopic techniques and the complexes [Au(p-CH3-C6H4-C[triple bond]C-S)PPh3], [Au(3-C4H3S-C[triple bond]C-S)PPh3] and PPN[Au(p-CH3-C6H4-C[triple bond]C-S)(C6F5)] by X-ray analysis. The electrochemically polymerizable mononuclear bis(alkynethiolate) gold(I) complex PPN[Au(3-C4H3S-C[triple bond]C-S)2] is also described, including its electropolymerization and electrochemical properties. 相似文献
94.
Saúl J. C. Salazar Humberto G. Laguna Vinod Prasad Robin P. Sagar 《International journal of quantum chemistry》2020,120(11):e26188
The appearance of critical points in the Shannon entropy sum as a function of confinement radius, in ground and excited state confined hydrogenic systems, is discussed. We illustrate that the Coulomb potential in tandem with the hard sphere confinement are responsible for these points. The positions of these points are observed to vary with the intensity of the potential. The effects of the Coulomb potential on the system are further probed, by examining the differences between the densities of the confined atom and those of the particle confined in a spherical box, for the same confinement radius. These differences are quantified by using Kullback-Leibler and cumulative residual Kullback-Leibler distance measures from information theory. These measures detect that the effects of the Coulomb potential are squeezed out of the system as the confinement radius decreases. That is, the confined atom densities resemble the particle in a box ones, for smaller confinement radii. Furthermore, the critical points in the entropy sum lie in the same regions where there are changes in the distance measures, as the atom behaves more particle in a spherical box-like. The analysis is further complemented by examination of the derivative of the entropy sum with respect to confinement radius. This study illustrates the inhomogeneity in the magnitudes of the derivatives of the entropy sum components and their dependence on the Coulomb potential. A link between the derivative and the entropic force is also illustrated and discussed. Similar behaviors are observed when the virial ratio is compared to the entropic power one, as a function of confinement radius. 相似文献
95.
Xabier Rios Paula Moriones Jesús C. Echeverría Asunción Luquín Mariano Laguna Julián J. Garrido 《Adsorption》2011,17(3):583-593
The mild synthetic conditions provided by the sol-gel process and the versatility of the colloidal state allow for the mixing
of inorganic and organic components at the nanometre scale in virtually any ratio for the preparation of hybrid materials.
Our interest in hybrid xerogels focuses on combining their porosity with other properties to prepare optic-fibre sensors.
The specific aim of this paper is to synthesise hybrid xerogels in acid media using methyltriethoxysilane (MTEOS) and tetraethoxysilane
(TEOS) as silica precursors and to investigate the effect of the MTEOS molar ratio on the structure and porous texture of
xerogels. Gelation time exponentially increased as the MTEOS molar ratio increased. Increasing the MTEOS molar ratio yielded
xerogels with lower density and lower particle size. The incorporation of MTEOS resulted in new FTIR bands at 1276 and 791 cm−1, which was attributed to vibrational modes of methyl group. The band around 1092 cm−1 associated with siloxane bonds shifted to lower wavenumbers and split into two bands. The 29Si spectra only showed the Q
n
(n=2, 3, 4) signal in xerogels with 0% MTEOS and the T
n
(n=2, 3) signal in xerogels with 100% MTEOS; hybrid xerogels showed both Q and T signals. From XRD peaks at 2θ around 9°, we inferred that xerogels (>70% MTEOS) consisted of nanocrystalline CH3–SiO3/2 species. Increasing the MTEOS molar ratio produced xerogels with lower pore volumes and lower average pore size. The integration
of methyl groups on the surface decreased the surface polarity and, in turn, the characteristic energy. 相似文献
96.
Mohammad‐Reza Azani Dr. Oscar Castillo Dr. M. Luz Gallego Dr. Teodor Parella Dr. Gabriel Aullón Dr. Olga Crespo Prof. Dr. Antonio Laguna Prof. Dr. Santiago Alvarez Dr. Rubén Mas‐Ballesté Dr. Félix Zamora 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(32):9965-9976
The present study is aimed at elucidating the factors that direct the assembly of a specific family of AuI species. The assembly of AuI centers and dithiocarboxylato or xanthato ligands results in a surprising structural diversity observed by single‐crystal X‐ray diffraction. However, in solution, just evidences for discrete bimetallic [Au2L2] species have been observed. Interestingly, when dithiocarboxylato ligands have been used, a reversible supramolecular assembly has been observed forming the supramolecules of formulae [Au2L2]2 and [Au2L2]3. Initial studies on luminescent properties have been carried out at variable temperature. All the compounds show red emissions in the solid state at very similar energies, suggesting that the intramolecular interactions play a more relevant role in the luminescent properties than the intermolecular ones. The computational studies indicate that not only Au???Au interactions, but also Au???S and S???S ones play a role in the structure and energetic of the supramolecular species, as well as for the choice between supramolecular association or intramolecular oligomerization. 相似文献
97.
Mioso Roberto Bravo de Laguna Irma Herrera Marante Francisco J. Toledo Barbosa-Filho Jos M. 《平面色谱法杂志一现代薄层色谱法》2014,27(4):315-317
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
98.
The effects on the radiation response of Harwell polymethylmethacrylate (PMMA) dosimeters of dose-rate, radiation type, temperature during irradiation and post-irradiation storage, and post-irradiation stability, are of importance to the operators of commercial irradiation facilities.
This paper describes recent studies of the effects of some of these parameters on the radiation response of Harwell Red 4034, Amber 3042, and Gammachrome YR Perspex dosimeters, and provides data on batch to batch variation and shelf-life. 相似文献
99.
Codina A Fernández EJ Jones PG Laguna A López-De-Luzuriaga JM Monge M Olmos ME Pérez J Rodríguez MA 《Journal of the American Chemical Society》2002,124(23):6781-6786
[M(C6F5)(N(H)=CPh2)] (M = Ag (1) and Au (2)) complexes have been synthesized and characterized by X-ray diffraction analysis. Complex 1 shows a ladder-type structure in which two [Ag(C6F5)(N(H)=CPh2)] units are linked by a Ag(I)-Ag(I) interaction in an antiparallel disposition. The dimeric units are associated through hydrogen bonds of the type N-H...F(ortho). On the other hand, gold(I) complex 2 displays discrete dimers also in an antiparallel conformation in which both Au(I)-Au(I) interactions and N-H.F(ortho) hydrogen bonds appear within the dimeric units. The features of these coexisting interactions have been theoretically studied by ab initio calculations based on four different model systems in order to analyze them separately. The interactions have been analyzed at HF and MP2 levels of theory showing that, in this case, even at larger distances. The Au(I)-Au(I) interaction is stronger than Ag(I)-Ag(I) and that N-H.F hydrogen bonding and Au(I)-Au(I) contacts have a similar strength in the same molecule, which permits a competition between these two structural motifs giving rise to different structural arrangements. 相似文献
100.
A time-resolved technique has been developed for the detection of CH3 radicals in the gas phase by diode laser absorption at 608 cm?1 on a rotation-vibration transition of the v2 mode of CH3. The usefulness of the technique as a probe of the reaction kinetics is demonstrated by the measurement of the recombination rate of CH3 radicals and the third-body reaction rate of CH3 with O2 at room temperature. 相似文献