Browsing by Author "Ramirez, Paola"

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    Cyclometallated platinum(II) complexes containing the chiral ligand [2-(diphenyl-phosphanyl)-benzylidene]-(1-phenyl-ethyl)-amine: Synthesis and molecular structures of the compounds [PtCl(Me){kappa(2)-(R)-Ph2P(C6H4)CH=NCH(Ph)Me-P,N}] and [Pt{kappa(3)-(S)-Ph2P(C6H4)CH=NCH(C6H4)Me-P,N,C}Py]BF4
    (ELSEVIER SCIENCE SA, 2008) Ramirez, Paola; Contreras, Raul; Valderrama, Mauricio; Carmona, Daniel; Lahoz, Fernando J.; Balana, Ana I.
    Diastoreoisomeric mixtures of the complex [PtIMe3{kappa(2)-Ph2P(C6H4)CH=NCH(Ph)Me-P,N}] (Rc-1) react with AgBF4 and SMePh to give a mixture of complexes [PtMe(SMePh) {kappa(2)-Ph2P(C6H4)CH=NCH(Ph)Me-P,N}]BF4 (2) and [Pt{kappa(2)-Ph2P(C(6)H4)CH=NCH(C6H4)Me-P,N,C}(PhSMe)]BF4 (3) which subsequently render the corresponding chloride compounds [PtClMe{kappa(2)-(R)-Ph2P(C6H4)CH=NCH(Ph)Me-P,N}] (4) and [PtCl{kappa(3)-(R)-Ph2P(C6H4)CH=NCH(C6H4)Me-P,N,C}] (5), by elution with CH2Cl2 on a aluminium oxide chromatography column. Refluxing of [PtIMe3{kappa(2)-Ph2P(C6H4)CH=NC*H(Ph)Me-P,N}] (Sc-1) with AgBF4 in a 1:1, CH2Cl2:Me2CO mixture followed by the addition of SMePh, NCMe or pyridine (Py) affords the corresponding cyclometallated compounds [Pt{kappa(3)-(S)-Ph2P(C6H4)CH=NCH(C6H4)Me-P,N,C}(L)]BF4 [L = SMePh (3), NCMe (9), Py (10)]. These compounds have been characterised by analytical and spectroscopic means and by the molecular structure determination of complexes 4 and 10. (C) 2007 Elsevier B.V. All rights reserved.
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    Geological and geotechnical investigation of the seismic ground response characteristics in some urban and suburban sites in Chile exposed to large seismic threats
    (2022) Maringue, Jose; Mendoza, Laura; Saez, Esteban; Yanez, Gonzalo; Montalva, Gonzalo; Soto, Valeria; Ayala, Felipe; Perez-Estay, Nicolas; Figueroa, Ronny; Sepulveda, Natalia; Galvez, Carlos; Ramirez, Paola; Ovalle, Carlos
    The central area of Chile's Valparaiso Region has been classified as a seismic gap for a major earthquake, which makes it very important to understand the seismic hazard of the zone. Generally, seismic codes consider a qualitative classification of sites to estimate the possible damage in the case of an earthquake scenario. Estimating the values of acceleration could be very important to prevent damages and increase preparedness for these rare events. In this research, a qualitative and quantitative estimation of seismic hazard is performed in the study area (Valparaiso region between Papudo and San Antonio 32 degrees-34 degrees S). This is achieved through an integrated and relatively economical approach which considers the information from Geology, Geophysical experiments (Gravity and seismic methods), and Geotechnical analyses. The results of the geophysical survey and geology information allow dividing the zone into five site types through a new proposal of site classification that depends not only on the V-s30,V- but also on the sites predominant period (T-0), which is an innovation of this work for the Chilean code. The Peak Ground Acceleration (PGA) values in the study zone were estimated using a Ground Motion Predictive Equation developed for the Chilean subduction zone. Additionally, we consider three different seismic scenarios according to the history of events in Central Chile. The results of this quantitative analysis show PGA values up to 0.52 g for the median and 1.2 g for the 84th percentile of the scenarios. Overall, the highest accelerations (PGA) are in zones with low shear wave velocities (< 500 m/s), a long predominant period (> 0.4 s) and where geology establishes the presence of low stiffness soils. The comparison of response spectra from the model against records from 2010 Maule and 1985 Valparaiso earthquakes shows available models tend to overpredict the intensities.