Antitumor and antimycobacterial activities of cyclopalladated complexes: X-ray structure of [Pd(C-2,N-dmba)(Br)(tu)] (dmba = N,N-dimethylbenzylamine, tu = thiourea)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fatigue strength of HVOF sprayed Cr(3)C(2)-25NiCr and WC-10Ni on AISI 4340 steel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Binuclear cyclopalladated compounds with antitubercular activity: synthesis and characterization of [{Pd(C-2,N-dmba)(X)}(2)(mu-bpp)] (X = Cl, Br, NCO, N-3; bpp=1,3-bis(4-pyridyl)propane)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

1,3-dipolar cycloaddition of CS2 to the coordinated azide in the cyclopalladated [Pd(bzan)(mu-N-3)](2). Crystal and molecular structure of di(mu-N,S-1,2,3,4-thiatriazole-5-thiolate)bis[(benzylideneaniline-C-2,N)palladium(II)]

The compound [Pd(bzan)(mu -N-3)](2) 1, bzan = benzylideneaniline, was prepared from [Pd(bzan) (mu -OOCCH3)](2) by an anion exchange reaction. The 1,3-dipolar cycloaddition of carbon disulfide to the bridged coordinated azide in the cyclometallated compound I was investigated. The species resulting from this reaction, di(mu -N,S-1,2,3,4-thiatriazol-5-thiolate)bis[(benzylideneaniline)palladium(II)] 2, was characterized by IR spectroscopy and X-ray diffraction. The compound 2 is a dimer containing two [Pd(benzylideneaniline)] moieties connected by two vicinal bridging N,S-1,2,3,4-thiatriazole-5-thiolate anions in a square-planar coordination geometry for the palladium atoms.

Cycloaddition reaction of the azido-bridged cyclometallated complex [Pd(dmba)N-3](2) with CS2. Crystal and molecular structure of DI(mu, N,S-1,2,3,4-thiatriazole-5-thiolate) bis[(N,N-dimethylbenzyl-amine-C-2,N)palladium(II)]

The 1,3-dipolar cycloaddition of carbon disulfide to the coordinated azide in the cyclometallated compound [Pd(dmba)(N-3)](2) (1), dmba = N,N-dimethylbenzylamine, was investigated. The compound obtained di(mu, N,S-1,2,3,4-thiatriazole-5-thiolate)-bis[(N,N-dimethylbenzylamine-C-2,N)palladium(II)] (2), was characterized by IR spectroscopy and X-ray diffraction. Complex (2) is dimeric with the two [Pd(N,N-dimethylbenzylamine)] moieties being connected by the two vicinal bridging N,S-1,2,3,4-thiatriazole-5-thiolate anions in a square-planar coordination for the palladium atoms.

SYNTHESIS AND CRYSTAL-STRUCTURE OF THE NOVEL CYCLOPALLADATED COMPLEX DI(MU,N-S-ETA(2)-QUINOLINE-2-THIOLATE)-BIS[(N,N-DIMETHYLBENZYLAMINE-C(2),N) PALLADIUM(II)]

The compound di(mu,N-Seta2-2-quinoline-2-thiolate)-bis[(N,N-dimethylbenzylamine-C2,N)palladium(II)] was synthesized and studied by IR, NMR and X-ray diffraction: monoclinic, a = 20.138(3), b = 10.831(1), c = 14.973(2) angstrom, beta = 98.04(1)-degrees, Z = 4, space group P2(1)/c, R = 0.032. The compound is dimeric with the two [Pd(N,N-dimethylbenzylamine)]moieties being connected by the two vicinal bridging eta2-N,S-quinoline-2-thiolate anions in a square-planar coordination geometry for the palladium atoms.

Crystal structure of di-mu(N,S)-thiocyanato-bis[(N-benzylideneaniline-C-2,N)palladium(II)], [Pd(C6H4CH=NC6H5)(mu-SCN)](2)

C28H20N4Pd2S2, monoclinic, P12(1)/c1 (No. 14), a = 11.325(1) Angstrom, b = 13.530(1) Angstrom, c = 17.925(1) Angstrom, beta = 106.23(1)degrees, V = 2637.1 Angstrom(3), Z = 4, R-gt(F) = 0.052, wR(ref)(F-2) = 0.129, T = 293 K.

Crystal structure of di-μ(N,S)-thiocyanato-bis[(N-benzylideneaniline-C 2,N)palladium(II)], [Pd(C6H4CH=NC 6H5)(μ-SCN)]2

C28H20N4Pd2S2, monoclinic, P121/c1 (No. 14), a = 11.325(1) Å, b = 13.530(1) Å, c = 17.925(1) Å, β = 106.23(1)°, V = 2637.1 Å 3, Z = 4, Rgt(F) = 0.052, wRref(F2) = 0.129, T = 293 K. © by Oldenbourg Wissenschaftsverlag.

C-2, N-dimethylbenzylamine cyclopalladated compounds: evaluation of cytotoxic, mutagenic and antitubercular activities

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Double point curves for corank 2 map germs from C-2 to C-3

We characterize finite determinacy of map germs f : (C-2, 0) -> (C-3, 0) in terms of the Milnor number mu(D(f)) of the double point curve D(f) in (C-2, 0) and we provide an explicit description of the double point scheme in terms of elementary symmetric functions. Also we prove that the Whitney equisingularity of 1-parameter families of map germs f(t) : (C-2, 0) -> (C-3, 0) is equivalent to the constancy of both mu(D(f(t))) and mu(f(t)(C-2)boolean AND H) with respect to t, where H subset of C-3 is a generic plane. (C) 2011 Elsevier B.V. All rights reserved.

Ionization of chlorophyll-c(2) in liquid methanol

The ionization of chlorophyll-c(2) in liquid methanol was investigated by a sequential quantum mechanical/Monte Carlo approach. Focus was placed on the determination of the first ionization energy of chlorophyll-c(2). The results show that the first vertical ionization energy (IE) is red-shifted by 0.47 +/- 0.24 eV relative to the gas-phase value. The red-shift of the chlorophyll-c(2) IE in the liquid phase can be explained by Mg center dot center dot center dot OH hydrogen bonding and long-ranged electrostatic interactions in solution. The ionization threshold for chlorophyll-c2 in liquid methanol is close to 6 eV. (C) 2012 Elsevier B.V. All rights reserved.

Bestimmung des elektrischen Formfaktors des Neutrons G en in der Reaktion 3 He (e,e'n) bei einem Impulsübertrag Q 2 =0.67 (GeV/c) 2

In der Überprüfung von Kernmodellen stellt der elektrische Formfaktor des Neutrons Gen eine wichtige Eingangsgröße dar. Im Rahmen dieser Arbeit wurde am polarisierten Elektronenstrahl des Mainzer Mikrotrons MAMI der elektrische Formfaktor des Neutrons in der Reaktion 3He(e,e'n) bestimmt. Aus dem Verhältnis der Asymmetrien respektive der Helizitätsumkehr der Elektronenpolarisation mit Targetspin senkrecht und parallel zum Impulsübertrag konnte in einer integralen Analyse Gen bestimmt werden. Zusammengefasst ergab sich Gen(Q2=0.67 (GeV/c)2) = 0.0468 +- 0.0064(stat} +- 0.0027(syst}. Um den Einfluß von Kernbindungseffekten, die z. Zt. von der Gruppe um Prof. Glöckle in Bochum theoretisch gerechnet werden, auch experimentell abzusichern, wurden parallel zur Gen-Messung die Targetasymmetrie Ay0 3He(e,e'n) und Protonenasymmetrie 3He(e,e'p) bestimmt. Die Empfindlichkeit dieser Observablen auf FSI und D-Wellenbeiträge schafft Redundanzen, aus denen auf die Eigenschaften des freien Neutrons im gebundenen System geschlossen werden kann.

Measurement of the elastic electron-proton cross section and separation of the electric and magnetic form factor in the Q 2 range from 0.004 to 1 (GeV/c) 2

The electromagnetic form factors of the proton are fundamental quantities sensitive to the distribution of charge and magnetization inside the proton. Precise knowledge of the form factors, in particular of the charge and magnetization radii provide strong tests for theory in the non-perturbative regime of QCD. However, the existing data at Q^2 below 1 (GeV/c)^2 are not precise enough for a hard test of theoretical predictions.rnrnFor a more precise determination of the form factors, within this work more than 1400 cross sections of the reaction H(e,e′)p were measured at the Mainz Microtron MAMI using the 3-spectrometer-facility of the A1-collaboration. The data were taken in three periods in the years 2006 and 2007 using beam energies of 180, 315, 450, 585, 720 and 855 MeV. They cover the Q^2 region from 0.004 to 1 (GeV/c)^2 with counting rate uncertainties below 0.2% for most of the data points. The relative luminosity of the measurements was determined using one of the spectrometers as a luminosity monitor. The overlapping acceptances of the measurements maximize the internal redundancy of the data and allow, together with several additions to the standard experimental setup, for tight control of systematic uncertainties.rnTo account for the radiative processes, an event generator was developed and implemented in the simulation package of the analysis software which works without peaking approximation by explicitly calculating the Bethe-Heitler and Born Feynman diagrams for each event.rnTo separate the form factors and to determine the radii, the data were analyzed by fitting a wide selection of form factor models directly to the measured cross sections. These fits also determined the absolute normalization of the different data subsets. The validity of this method was tested with extensive simulations. The results were compared to an extraction via the standard Rosenbluth technique.rnrnThe dip structure in G_E that was seen in the analysis of the previous world data shows up in a modified form. When compared to the standard-dipole form factor as a smooth curve, the extracted G_E exhibits a strong change of the slope around 0.1 (GeV/c)^2, and in the magnetic form factor a dip around 0.2 (GeV/c)^2 is found. This may be taken as indications for a pion cloud. For higher Q^2, the fits yield larger values for G_M than previous measurements, in agreement with form factor ratios from recent precise polarized measurements in the Q2 region up to 0.6 (GeV/c)^2.rnrnThe charge and magnetic rms radii are determined as rn⟨r_e⟩=0.879 ± 0.005(stat.) ± 0.004(syst.) ± 0.002(model) ± 0.004(group) fm,rn⟨r_m⟩=0.777 ± 0.013(stat.) ± 0.009(syst.) ± 0.005(model) ± 0.002(group) fm.rnThis charge radius is significantly larger than theoretical predictions and than the radius of the standard dipole. However, it is in agreement with earlier results measured at the Mainz linear accelerator and with determinations from Hydrogen Lamb shift measurements. The extracted magnetic radius is smaller than previous determinations and than the standard-dipole value.

Messung des elektrischen Neutron-Formfaktors in der Reaktion 3 He(e,e'n)pp bei Q 2 = 1.58 (GeV/c) 2

Die elektromagnetischen Nukleon-Formfaktoren sind fundamentale Größen, welche eng mit der elektromagnetischen Struktur der Nukleonen zusammenhängen. Der Verlauf der elektrischen und magnetischen Sachs-Formfaktoren G_E und G_M gegen Q^2, das negative Quadrat des Viererimpulsübertrags im elektromagnetischen Streuprozess, steht über die Fouriertransformation in direkter Beziehung zu der räumlichen Ladungs- und Strom-Verteilung in den Nukleonen. Präzise Messungen der Formfaktoren über einen weiten Q^2-Bereich werden daher für ein quantitatives Verständnis der Nukleonstruktur benötigt.rnrnDa es keine freien Neutrontargets gibt, gestaltet sich die Messung der Neutron-Formfaktoren schwierig im Vergleich zu der Messung am Proton. Konsequenz daraus ist, dass die Genauigkeit der vorhandenen Daten von Neutron-Formfaktoren deutlich geringer ist als die von Formfaktoren des Protons; auch der vermessene Q^2-Bereich ist kleiner. Insbesondere der elektrische Sachs-Formfaktor des Neutrons G_E^n ist schwierig zu messen, da er aufgrund der verschwindenden Nettoladung des Neutrons im Verhältnis zu den übrigen Nukleon-Formfaktoren sehr klein ist. G_E^n charakterisiert die Ladungsverteilung des elektrisch neutralen Neutrons und ist damit besonders sensitiv auf die innere Struktur des Neutrons.rnrnIn der hier vorgestellten Arbeit wurde G_E^n aus Strahlhelizitätsasymmetrien in der quasielastischen Streuung vec{3He}(vec{e}, e'n)pp bei einem Impulsübertrag von Q^2 = 1.58 (GeV/c)^2 bestimmt. Die Messung fand in Mainz an der Elektronbeschleunigeranlage Mainzer Mikrotron innerhalb der A1-Kollaboration im Sommer 2008 statt. rnrnLongitudinal polarisierte Elektronen mit einer Energie von 1.508 GeV wurden an einem polarisierten ^3He-Gastarget, das als effektives, polarisiertes Neutrontarget diente, gestreut. Die gestreuten Elektronen wurden in Koinzidenz mit den herausgeschlagenen Neutronen detektiert; die Elektronen wurden in einem magnetischen Spektrometer nachgewiesen, durch den Nachweis der Neutronen in einer Matrix aus Plastikszintillatoren wurde der Beitrag der quasielastischen Streuung am Proton unterdrückt.rnrnAsymmetrien des Wirkungsquerschnitts bezüglich der Elektronhelizität sind bei Orientierung der Targetpolarisation in der Streuebene und senkrecht zum Impulsübertrag sensitiv auf G_E^n / G_M^n; mittels deren Messung kann G_E^n bestimmt werden, da der magnetische Formfaktor G_M^n mit vergleichsweise hoher Präzision bekannt ist. Zusätzliche Messungen der Asymmetrie bei einer Polarisationsorientierung parallel zum Impulsübertrag wurden genutzt, um systematische Fehler zu reduzieren.rnrnFür die Messung inklusive statistischem (stat) und systematischem (sys) Fehler ergab sich G_E^n = 0.0244 +/- 0.0057_stat +/- 0.0016_sys.