Search results for "Solid-state"
showing 10 items of 530 documents
Spin crossover behavior in a series of iron(III) alkoxide complexes.
2015
The synthesis, crystal structures, magnetic behavior, and electron paramagnetic resonance studies of five new FeIII spin crossover (SCO) complexes are reported. The [FeIIIN5O] coordination core is constituted of the pentadentate ligand bztpen (N5) and a series of alkoxide anions (ethoxide, propoxide, n-butoxide, isobutoxide, and ethylene glycoxide). The methoxide derivative previously reported by us is also reinvestigated. The six complexes crystallize in the orthorhombic Pbca space group and show similar molecular structures and crystal packing. The coordination octahedron is strongly distorted in both the high- and low-temperature structures. The structural changes upon spin conversion ar…
Nonlinear quantum Langevin equations for bosonic modes in solid-state systems
2017
Based on the experimental evidence that impurities contribute to the dissipation properties of solid-state open quantum systems, we provide here a description in terms of nonlinear quantum Langevin equations of the role played by two-level systems in the dynamics of a bosonic degree of freedom. Our starting point is represented by the description of the system/environment coupling in terms of coupling to two separate reservoirs, modelling the interaction with external bosonic modes and two level systems, respectively. Furthermore, we show how this model represents a specific example of a class of open quantum systems that can be described by nonlinear quantum Langevin equations. Our analysi…
Incorporation of a tricationic subphthalocyanine in an organic photovoltaic device
2013
A new tricationic subphthalocyanine was synthesized and employed as light-harvesting and donor material in an ionic solid state organic photovoltaic cell. The incorporation of ionic dyes in organic photovoltaics aims to take advantage of ionic movement in order to enhance the charge transport properties of these materials. In this preliminary study, we report the results obtained in the fabrication of a partially solution-processed device with a cationic dye, where an effiency of 0.5% was reached.
Floquet analysis of excitations in materials
2019
Abstract Controlled excitation of materials can transiently induce changed or novel properties with many fundamental and technological implications. Especially, the concept of Floquet engineering and the manipulation of the electronic structure via dressing with external lasers have attracted some recent interest. Here we review the progress made in defining Floquet material properties and give a special focus on their signatures in experimental observables as well as considering recent experiments realizing Floquet phases in solid state materials. We discuss how a wide range of experiments with non-equilibrium electronic structure can be viewed by employing Floquet theory as an analysis to…
High-pressure lattice dynamics in wurtzite and rocksalt indium nitride investigated by means of Raman spectroscopy
2013
We present an experimental and theoretical lattice-dynamical study of InN at high hydrostatic pressures. We perform Raman scattering measurements on five InN epilayers, with different residual strain and free electron concentrations. The experimental results are analyzed in terms of ab initio lattice-dynamical calculations on both wurtzite InN (w-InN) and rocksalt InN (rs-InN) as a function of pressure. Experimental and theoretical pressure coefficients of the optical modes in w-InN are compared, and the role of residual strain on the measured pressure coefficients is analyzed. In the case of the LO band, we analyze and discuss its pressure behavior considering the double-resonance mechanis…
Green Light-Emitting Solid-State Electrochemical Cell Obtained from a Homoleptic Iridium(III) Complex Containing Ionically Charged Ligands
2006
An efficient bluish-green light-emitting Ir(III) complex was prepared by introducing charged side groups onto phenylpyridine ligands. Green light emission with a first maximum at 487 nm (CIE coordinates x = 0.337 and y = 0.501) was observed from a single layer light-emitting electrochemical cell using this new complex; this is the lowest wavelength observed so far for devices based on ionic transition metal complexes.
Aromatic N-oxide templates open inclusion and dimeric capsular assemblies with methylresorcinarene
2015
C2-2-methylresorcinarene forms host–guest complexes with pyridine N-oxide and quinoline N-oxide. In solution the NMR studies support the 1 : 1 host–guest complexes while in the solid state, the single crystal X-ray diffraction studies reveal dimeric capsule-like assemblies with 2 : 3 and 2 : 2 host–guest stoichiometry.
119Sn M�ssbauer studies of bis[cysteinato(1?)-S]- and bis[penicillaminato(1?)-S]-diorganotin(IV) species in the crystalline state and in frozen aqueo…
1988
The bonding and the configuration of the tin environment in the title compounds {R2Sn[SCH2CH(NH3+)COO−]2 and R2Sn[SC(CH3)2CH(NH3+)COO−]2, indicated in the following as R2Sn(cysH)2 and R2Sn(penH)2 respectively} has been investigated through the determination of the Mossbauer-Zeeman spectra of Ph2Sn(cysH)2 and Ph2Sn(penH)2 in the solid state, and through conventional Mossbauer spectroscopy of Me2Sn(penH)2 in the solid state as well as of Me2Sn(cysH)2 and Me2Sn(penH)2 in aqueous solution (frozen). The treatment of the data by the pointcharge model approach suggested the general occurrence of a tetrahedral C2SnS2 core. In aqueous Hepes buffer, a tertiary amino nitrogen atom has been observed to…
Approximate energy functionals for one-body reduced density matrix functional theory from many-body perturbation theory
2018
We develop a systematic approach to construct energy functionals of the one-particle reduced density matrix (1RDM) for equilibrium systems at finite temperature. The starting point of our formulation is the grand potential $\Omega [\mathbf{G}]$ regarded as variational functional of the Green's function $G$ based on diagrammatic many-body perturbation theory and for which we consider either the Klein or Luttinger-Ward form. By restricting the input Green's function to be one-to-one related to a set on one-particle reduced density matrices (1RDM) this functional becomes a functional of the 1RDM. To establish the one-to-one mapping we use that, at any finite temperature and for a given 1RDM $\…
Neutral Organometallic Halogen Bond Acceptors: Halogen Bonding in Complexes of PCPPdX (X = Cl, Br, I) with Iodine (I(2)), 1,4-Diiodotetrafluorobenzen…
2012
The behavior of a sterically crowded neutral pincer {2,6-bis[(di-t-butylphosphino)methyl]-phenyl}palladium (PCPPd) halides, PCPPdX (X = Cl, Br or I), as XB acceptors with strong halogen bond (XB) donors, iodine (I2), 1,4-diiodotetrafluorobenzene (F4DIBz), and 1,4-diiodooctafluorobutane (F8DIBu) were studied in the solid state. The co-crystallization experiments afforded high-quality single crystals of XB complexes PCPPdCl–I2 (1a), PCPPdBr–I2 (2a), PCPPdI–I2(3a), PCPPdCl–F4DIBz (1b), PCPPdBr–F4DIBz (2b), and PCPPdBr–F8DIBu (2c). The 1:1 iodine complexes (1a, 2a, and 3a) all showed a strong halogen bonding interaction, the reduction of the sum of the van der Waals radii of halogen to iodine b…