Search results for "Complexes"
showing 10 items of 875 documents
NHC-Based Iron Sensitizers for DSSCs
2018
International audience; Nanostructured dye-sensitized solar cells (DSSCs) are promising photovoltaic devices because of their low cost and transparency. Ruthenium polypyridine complexes have long been considered as lead sensitizers for DSSCs, allowing them to reach up to 11% conversion efficiency. However, ruthenium suffers from serious drawbacks potentially limiting its widespread applicability, mainly related to its potential toxicity and scarcity. This has motivated continuous research efforts to develop valuable alternatives from cheap earth-abundant metals, and among them, iron is particularly attractive. Making iron complexes applicable in DSSCs is highly challenging due to an ultrafa…
Recent Advances of Spin Crossover Research
2004
Thermal spin transition (spin crossover), one of the most fascinating dynamic electronic structure phenomena occurring in coordination compounds of third row transition metal ions, mostly of iron(II), iron(III) and cobalt(II) with critical ligand field strengths competing with the spin pairing energy, has attracted increasing attention by many research groups. One of the reasons is the promising potential for practical applications. In this chapter we intend to cover essential recent work, primarily accomplished within the European research network on "Thermal and Optical Switching of Molecular Spin States (TOSS)". New spin crossover compounds and their thermal spin transition behaviour, al…
Hydrolysis of Monomethyl-, Dimethyl-, and Trimethyltin(IV) Cations in Fairly Concentrated Aqueous Solutions at I = 1 mol L-1 (NaNO3) and T = 298.15 K…
2011
The hydrolysis of methyltin(IV) cations at fairly high concentrations was investigated to evaluate the formation of polynuclear species in aqueous solution. The hydrolysis of monomethyltin(IV), dimethyltin(IV), and trimethyltin(IV) was studied by potentiometry at T = 298.15 K and at I = 1 mol L-1 in NaNO3 aqueous solutions. The results obtained gave evidence for the formation of the following polynuclear species, in addition to the mononuclear species already reported, which were also considered in the models proposed for the three systems investigated: [(CH3)Sn(OH)3]0, [(CH3)Sn(OH)4]-, [((CH3)Sn)2(OH)4]2+, [((CH3)Sn)2(OH)5]+, [((CH3)Sn)2(OH)7]-, [((CH3)Sn)3(OH)5]4+, [((CH3)Sn)3(OH)7]2þ, [(…
Polynitrile anions as ligands: From magnetic polymeric architectures to spin crossover materials
2010
International audience; The use of polynitrile anions as ligands (L) either alone or in combination with neutral co-ligands (L′) is a very promising and appealing strategy to get molecular architectures with different topologies and dimensionalities thanks to their ability to coordinate and bridge metal ions in many different ways. The presence of several potentially coordinating nitrile groups (or even other donor groups as –OH, –SH or –NH2), their rigidity and their electronic delocalization allow the synthesis of original magnetic high dimensional coordination polymers with transition metals ions. Furthermore, these ligands have shown coordinating and bridging capabilities in novel discr…
Pt(II) nitrile complexes: New insights on old complexes from a combined experimental and theoretical study
2017
Abstract The spectroscopic characterization of cis - and trans -[PtCl 2 (NCR) 2 ] (R = CH 3 , Ph, CH 2 Ph) was reported in solid state and solution phase. Moreover, the X-ray structures of cis -[PtCl 2 (NCCH 3 ) 2 ], cis - and trans -[PtCl 2 (NCPh) 2 ] were redetermined at low temperature. FT-IR and NMR showed a blue-shift and a slight shielding of the νCN and δ ( 13 C CN ) values, respectively, in a counterintuitive way with respect to the well known improved reactivity towards nucleophiles of nitriles ligands coordinated to platinum(II), when compared to their free forms. These spectroscopic behaviors were also confirmed by theoretical experiments at DFT level. Moreover, DFT approach show…
Half-sandwich Mo(III) complexes with asymmetric diazadiene ligands
2006
The asymmetric 1,4-diazadiene ligands R ∗ N CHCH NR ∗ [R ∗ = ( S )-CH(CH 3 )Ph], R 2 ∗ dad , and 2,2′-bis(4-ethyloxazoline), as-ox, have been used to generate half-sandwich Mo III derivatives by addition to Cp 2 Mo 2 Cl 4 . Ligand R 2 ∗ dad affords a mononuclear, paramagnetic 17-electron product, CpMoCl 2 ( R 2 ∗ dad ) , whereas as-ox leads to the isolation of a dinuclear compound where only one molecule of ligand has been added per two Mo atoms, Cp 2 Mo 2 Cl 4 (as-ox). In the presence of free as-ox, this compound coexists with the paramagnetic mononuclear complex in solution. Both products are capable of controlling the radical polymerization of styrene under typical atom transfer radical…
Tetrathiafulvalene-Polychlorotriphenylmethyl Dyads: Influence of Bridge and Open-Shell Characteristics on Linear and Nonlinear Optical Properties
2017
Three conjugated donor-π-acceptor radical systems (1 a–1 c) were prepared by bridging a tetrathiafulvalene (TTF) electron-donor unit to a polychlorotriphenylmethyl (PTM) electron-acceptor radical through vinylene units of different lengths. The dependence of the intramolecular charge transfer on the length of the conjugated bridge has been analyzed by different electrochemical and spectroscopic techniques. Linear optical properties and the second-order nonlinear optical (NLO) response of these derivatives have been computed by comparing systems 1 a–1 c with the non-radical analogues (2 a–2 c). Interestingly, an enhanced NLO response is predicted for dyads 1 a–1 c with PTM in the radical for…
Deregulation of the EGFR/PI3K/PTEN/Akt/mTORC1 pathway in breast cancer: possibilities for therapeutic intervention
2014
// Nicole M. Davis 1 , Melissa Sokolosky 1 , Kristin Stadelman 1 , Stephen L. Abrams 1 , Massimo Libra 2 , Saverio Candido 2 , Ferdinando Nicoletti 2 , Jerry Polesel 3 , Roberta Maestro 4 , Antonino D’Assoro 5 , Lyudmyla Drobot 6 , Dariusz Rakus 7 , Agnieszka Gizak 7 , Piotr Laidler 8 , Joanna Dulinska-Litewka 8 , Joerg Basecke 9 , Sanja Mijatovic 10 , Danijela Maksimovic-Ivanic 10 , Giuseppe Montalto 11,12 , Melchiorre Cervello 12 , Timothy L. Fitzgerald 13 , Zoya N. Demidenko 14 , Alberto M. Martelli 15 , Lucio Cocco 15 , Linda S. Steelman 1 and James A. McCubrey 1 1 Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University Greenville, NC 27858 USA 2 …
Optical Fibre NO2 Sensor Based on Lutetium Bisphthalocyanine in a Mesoporous Silica Matrix
2018
International audience; In this article, we describe a NO2 sensor consisting of a coating based on lutetium bisphthalocyanine (LuPc2) in mesoporous silica. The sensor exploits the absorption spectrum change of this material which strongly and reversibly decreases in contact with NO2. NO2 is measured by following the amplitude change in the reflected spectrum of the coating deposited on the tip of a silica fibre. As diffusion of NO2 in LuPc2 is slow, the response time could be slow. To reduce it, the active molecules are dispersed in a mesoporous silica matrix deposited by a sol-gel process (Evaporation Induced Self Assembly) avoiding the formation of large crystals. Doing so, the response i…