Search results for "complexe"

Méthodologie de modélisation et de caractérisation des réseaux spatiaux. Application au réseau viaire de Paris

2016

International audience; Les graphes spatialisés soulèvent différentes questions qui intéressent plusieurs disciplines, depuis la biologie (veinures de feuilles, réseaux neuronaux) ou la géomorphologie (réseaux fluviaux) jusqu’aux études urbaines (réseaux de transports), sans oublier celle des réseaux d’énergie (réseaux électriques, de gaz ou de pétrole) et de télécommunication. Nous nous concentrerons ici sur les exemples apportés par les réseaux viaires. C’est à travers ceux-ci que nous définirons dans cet article d’abord un objet d’étude multi-échelle, la voie, puis cinq indicateurs liés qui permettront une lecture enrichie de la spatialité urbaine. Nous expliciterons ainsi les particular…

Metal salen complexes as ethylene polymerization catalysts - effect of catalytic system composition on its activity and properties of polymerization …

2008

Zsyntetyzowano i zastosowano [po aktywacji metyloaluminoksanem (MAO) lub Et2AlCl] w charakterze katalizatorów niskociśnieniowej polimeryzacji etylenu serię salenowych kompleksów metali przejściowych różniących się rodzajem atomu centralnego (M=Ti, Zr lub V) i budową chemiczną ligandu (schemat A). Stwierdzono, że salenowe kompleksy cyrkonu są aktywne w polimeryzacji jedynie wówczas, gdy aktywator stanowi MAO, natomiast kompleksy tytanu i wanadu są aktywniejsze w przypadku gdy kokatalizatorem jest typowy związek glinoorganiczny - dietylochloroglin. Aktywność kompleksów w układzie z Et2AlCl zmienia się w szeregu V>Ti>>Zr?0, podczas gdy w odniesieniu do kompleksów aktywowanych MAO maleje ona w …

New hydroxyapatite- and selenium-based nanoformulations as potential antimicrobial tools for orthopedic implants

Entrapment of a linear water pentamer into a uranyl-salophen dimer in the solid state

2019

In the solid state, uranyl-salophen complex 1, decorated with bipyridyl sidearms, self-assembles from moist acetonitrile into dimeric species displaying a confined water pentamer, as observed by X-...

Laboratorium udręki wzajemnego bytowania na podstawie "Matki" Stanisława Ignacego Witkiewicza

2016

The topie of my article is solitude of the titled mother in the drama of Stanisław Ignacy Witkiewicz. The play was organized in Cracow’s The National Old Theatre by a magnificent and, unfortunately, deceased artist - Jerzy Jarocki. It is rare to experience such a piece of art where all human feelings are, in a radical way, mocked and rotten. Witkacy overemphasizes a motif of a widów mother - used by their children. It helped him in reaching a comic effect and ridiculing his characters. The Mother is an unpleasant play. In a fiction layer it shaped in a form of a parody of a psychological family drama, kept in poetics grotesąue poetics. Witkacy, obsessed with exposing the lowest human instin…

Functional molecular materials: supramolecular networks and coordination polymers with optical and/or magnetic properties

2020

El camp dels materials moleculars atrau l’atenció de molts científics degut al gran potencial de la química molecular en el disseny de materials amb un ajust precís de les seues propietats. Els dos projectes tractats en aquesta tesi representen dos temes que destaquen en aquesta àrea, materials de transició d’espín i polímers de coordinació amb propietats òptiques i/o magnètiques, gràcies al seu significant progrés i ràpid desenvolupament en els últims anys. La primera part d’aquesta tesi es basa en l’ús d’enllaços d’hidrogen en el disseny de xarxes multifuncionals de ferro(II) amb transicions d’espín abruptes. El capítol 1 és una introducció a aquest tema des de la perspectiva dels complex…

Thermodynamic and spectroscopic study of the binding of dimethyltin(IV) by citrate at 25°C

2006

Thermodynamic (potentiometric and calorimetric) and spectroscopic ( 1 H NMR, 119 Sn Mossbauer) studies were performed in aqueous solution in order to characterize the interaction of dimethyltin(IV) cation with citrate ligand. Six species {(CH 3 ) 2 Sn(cit) - ; [(CH 3 ) 2 Sn] 2 (cit) 2 2- ; (CH 3 ) 2 Sn(cit)H 0 ; (CH 3 ) 2 Sn(cit)OH 2- ; [(CH 3 ) 2 Sn] 2 (cit)OH 0 ; [(CH 3 ) 2 Sn] 2 (cit)(OH) 2 - } were found. All the species formed in this system are quite stable and formation percentages are fairly high. For example, at pH = 7.5 and C (CH3)2Sn = C cit = 10 mmol l -1 , E% for [(CH 3 ) 2 Sn] 2 (cit)(OH) 2 - and (CH 3 ) 2 Sn(cit)OH 2- species reaches 65%. Overall thermodynamic parameters obta…

A Theoretical and Experimental Investigation of the Spectroscopic Properties of a DNA-Intercalator Salphen-Type ZnIIComplex

2014

The photophysical and DNA-binding properties of the cationic zinc(II) complex of 5-triethylammonium methyl salicylidene ortho-phenylenediiminato (ZnL 2 + ) were investi- gated by a combination of experimental and theoretical methods. DFT calculations were performed on both the ground and the first excited states of ZnL 2 + and on its possi- ble mono- and dioxidation products, both in vacuo and in selected solvents mimicked by the polarizable continuum model. Comparison of the calculated absorption and fluores- cence transitions with the corresponding experimental data led to the conclusion that visible light induces a two-elec- tron photooxidation process located on the phenylenediimi- nato…

Role of Vibrational Dynamics in Electronic Relaxation of Cr(acac)3

2015

Ultrafast energy relaxation of Cr(acac)3 dissolved in tetrachloroethylene (TCE) is studied by time-resolved infrared (TRIR) spectroscopy by using electronic and vibrational excitation. After electronic excitation at 400 or 345 nm, the ground state recovers in two time scales: 15 ps (major pathway) and 800 ps (minor pathway), corresponding to fast electronic transition to the ground state and intermediate trapping on the long-lived (2)E state followed by intersystem crossing (ISC) to the ground state. The quantum yield for the fast recovery of the ground state depends on the excitation wavelength, being higher for 345 nm. Vibrational cooling (VC) occurs on the electronic excited states with …

One-pot synthesis and characterization of subnanometre-size benzotriazolate protected copper clusters

2012

A simple one-pot method for the preparation of subnanometre-size benzotriazolate (BTA) protected copper clusters, Cu(n)BTA(m), is reported. The clusters were analyzed by optical and infrared spectroscopy, mass spectrometry and transmission electron microscopy together with computational methods. We suggest a structural motif where the copper core of the Cu(n)BTA(m) clusters is protected by BTA-Cu(i)-BTA units.