Synthesis, Characterisation and DFT Analysis of {Ru(NO)2}8
... nitroprusside (SNP) as an example for the PLI-effect................................................................................................................12 Fig. 1.13: Some examples for mononitrosyl complexes. ................................................................................ ...
... nitroprusside (SNP) as an example for the PLI-effect................................................................................................................12 Fig. 1.13: Some examples for mononitrosyl complexes. ................................................................................ ...
Influence of Vanadium Location in Titania Supported
... applications.1,2 The HPA compounds can be considered as molecular solids because of the finite number of atoms in such subnanometer sized clusters (e.g., the H3PMo12O40 Keggin). The main advantage of HPAs is that their acidity and reactivity can be controlled by varying the addenda (Mo atoms in the ...
... applications.1,2 The HPA compounds can be considered as molecular solids because of the finite number of atoms in such subnanometer sized clusters (e.g., the H3PMo12O40 Keggin). The main advantage of HPAs is that their acidity and reactivity can be controlled by varying the addenda (Mo atoms in the ...
Immobilized Iron(III) Metal Affinity Chromatography for
... affinity between pH 3 and 5 is attributed to the ionization of the second acidic oxygen of phosphate. The affinity decreases above pH 5 due to the competitive binding of hydroxyl ions to Fe(II1). ...
... affinity between pH 3 and 5 is attributed to the ionization of the second acidic oxygen of phosphate. The affinity decreases above pH 5 due to the competitive binding of hydroxyl ions to Fe(II1). ...
High-Resolution X-ray Emission and X
... multiple scattering methods. Self-consistent full potential multiple scattering calculations have recently been carried out for TiO2 by Cabaret and co-workers.20 They show that with polarization-dependent calculations the complete spectral shape of TiO2 is nicely reproduced. In particular, the preed ...
... multiple scattering methods. Self-consistent full potential multiple scattering calculations have recently been carried out for TiO2 by Cabaret and co-workers.20 They show that with polarization-dependent calculations the complete spectral shape of TiO2 is nicely reproduced. In particular, the preed ...
Activation of Carbon-Fluorine Bonds by Metal
... a-orbitals on the adjacent carbon atom.41p42Synergistically, fluorine can act as a a-acceptor and pull electron density from the adjacent carbon atom as a result of its high electronegativity. It is this charge transfer from carbon to fluorine that is the cause for the observed progressive shortenin ...
... a-orbitals on the adjacent carbon atom.41p42Synergistically, fluorine can act as a a-acceptor and pull electron density from the adjacent carbon atom as a result of its high electronegativity. It is this charge transfer from carbon to fluorine that is the cause for the observed progressive shortenin ...
Thermodynamics: the Second Law
... to it, and water can be decomposed by the passage of an electric current. However, in each case we need to act in some way on the system to bring about the non-spontaneous change. There must be some feature of the world that accounts for the distinction between the two types of change. Throughout th ...
... to it, and water can be decomposed by the passage of an electric current. However, in each case we need to act in some way on the system to bring about the non-spontaneous change. There must be some feature of the world that accounts for the distinction between the two types of change. Throughout th ...
Chemical Processes at the Water-Manganite (γ-MnOOH
... state from -III to +VII10. Mn shows typical behaviour of the 3d transition metals10, which is partly explained by the crystal field theory, with splitting of the d orbitals to form nongenerate energy levels10. The high spin species of Mn(IV) and Mn(II) predominate in nature and have electron configu ...
... state from -III to +VII10. Mn shows typical behaviour of the 3d transition metals10, which is partly explained by the crystal field theory, with splitting of the d orbitals to form nongenerate energy levels10. The high spin species of Mn(IV) and Mn(II) predominate in nature and have electron configu ...
CH267 Transition Metal Chemistry
... Are any resources required for this module which are not already available from the Department’s own baseline resources (e.g. staff costs, accommodation, equipment, minor works, library costs, audio visual and computing facilities, vacation study requirements)? Is the module likely to require high u ...
... Are any resources required for this module which are not already available from the Department’s own baseline resources (e.g. staff costs, accommodation, equipment, minor works, library costs, audio visual and computing facilities, vacation study requirements)? Is the module likely to require high u ...
Controlling Subnanometer Gaps in Plasmonic Dimers Using
... charge transfer cannot occur, and the tuning and splitting of the two modes is set by the decreasing strength of the gap plasmon as the Au surfaces move further apart. The transverse modes (green lines) are not affected by the coupling, as expected from their charge distribution and consistent with o ...
... charge transfer cannot occur, and the tuning and splitting of the two modes is set by the decreasing strength of the gap plasmon as the Au surfaces move further apart. The transverse modes (green lines) are not affected by the coupling, as expected from their charge distribution and consistent with o ...
Ion-Pair Formation
... pairs in a saturated CaSO4 solution is almost as high as the concentration of the hydrated ions. Recall that the magnitude of attractive electrostatic interactions is greatest for small, highly charged ions. Hence ion pair formation is most important for salts that contain M2+ and M3+ ions, such as ...
... pairs in a saturated CaSO4 solution is almost as high as the concentration of the hydrated ions. Recall that the magnitude of attractive electrostatic interactions is greatest for small, highly charged ions. Hence ion pair formation is most important for salts that contain M2+ and M3+ ions, such as ...
Evolving Structural Diversity and Metallicity in Compressed Lithium
... The azide units in LiN3 are quite well separated (at 1 atm). The experimental N−N separation (1.162 Å)32 in N3− in LiN3 at 1 atm is similar to that in an isolated N3− (1.188 Å), as determined using velocity modulation spectroscopy in the gas phase.34 The Li−N (2.214 Å) and Li−Li (3.266 Å) separation ...
... The azide units in LiN3 are quite well separated (at 1 atm). The experimental N−N separation (1.162 Å)32 in N3− in LiN3 at 1 atm is similar to that in an isolated N3− (1.188 Å), as determined using velocity modulation spectroscopy in the gas phase.34 The Li−N (2.214 Å) and Li−Li (3.266 Å) separation ...
Sol-Gel Thermal Barrier Coating - Ewp.rpi.edu
... temperatures. In order to achieve this, current materials are being pushed to their thermal limits and to facilitate this, either new, higher-temperature capable materials or methods to protect existing materials from the environment must be established. One common method used today to protect subst ...
... temperatures. In order to achieve this, current materials are being pushed to their thermal limits and to facilitate this, either new, higher-temperature capable materials or methods to protect existing materials from the environment must be established. One common method used today to protect subst ...
Extraction of Heavy Metals from Fly Ash and Sand with Ligands and
... The extraction efficiency of heavy metals from sand matrixes with SC CO2 is influenced by a number of process parameters. Because of the sample preparation, the spiked metals are on the surface of the sand crystals. It must be taken into account that in most natural samples the particle morphology i ...
... The extraction efficiency of heavy metals from sand matrixes with SC CO2 is influenced by a number of process parameters. Because of the sample preparation, the spiked metals are on the surface of the sand crystals. It must be taken into account that in most natural samples the particle morphology i ...
View Article - Asian Journal of Chemistry
... stretching occurs in the region 1850-1550 cm-1. Because of high intensity and the relatively interference free region in which it occurs, this band is reasonably easy to recognize16. The sharp band present in the expected region being at 1708 and 1613 cm-1 in the FTIR spectrum is assigned to C=O str ...
... stretching occurs in the region 1850-1550 cm-1. Because of high intensity and the relatively interference free region in which it occurs, this band is reasonably easy to recognize16. The sharp band present in the expected region being at 1708 and 1613 cm-1 in the FTIR spectrum is assigned to C=O str ...
Activation of Propane CH and CC Bonds by Gas-Phase Pt
... units in heterogeneous catalysis can be aided by gas-phase study, which can provide insight into the intrinsic properties and reactivities of discrete and well-characterized catalytic species [3]. In particular, the activation of C-H and C-C bonds of propane by transition metals (neutral, cationic, ...
... units in heterogeneous catalysis can be aided by gas-phase study, which can provide insight into the intrinsic properties and reactivities of discrete and well-characterized catalytic species [3]. In particular, the activation of C-H and C-C bonds of propane by transition metals (neutral, cationic, ...
Mechanism of stibnite volatilization at high temperature
... partial pressures of S2 and O2 (marked as p(S2) and p(O2), respectively). This equilibrium diagram indicates that Sb2S3 in the presence of oxygen is first oxidized to Sb2O3 as an intermediate, and then, under higher p(O2) and low p(S2) in the vapor, it is further oxidized to SbO2. Generally, in trad ...
... partial pressures of S2 and O2 (marked as p(S2) and p(O2), respectively). This equilibrium diagram indicates that Sb2S3 in the presence of oxygen is first oxidized to Sb2O3 as an intermediate, and then, under higher p(O2) and low p(S2) in the vapor, it is further oxidized to SbO2. Generally, in trad ...
Spin crossover
Spin Crossover (SCO), sometimes referred to as spin transition or spin equilibrium behavior, is a phenomenon that occurs in some metal complexes wherein the spin state of the complex changes due to external stimuli such as a variation of temperature, pressure, light irradiation or an influence of a magnetic field.With regard to a ligand field and ligand field theory, the change in spin state is a transition from a low spin (LS) ground state electron configuration to a high spin (HS) ground state electron configuration of the metal’s d atomic orbitals (AOs), or vice versa. The magnitude of the ligand field splitting along with the pairing energy of the complex determines whether it will have a LS or HS electron configuration. A LS state occurs because the ligand field splitting (Δ) is greater than the pairing energy of the complex (which is an unfavorable process).Figure 1 is a simplified illustration of the metal’s d orbital splitting in the presence of an octahedral ligand field. A large splitting between the t2g and eg AOs requires a substantial amount of energy for the electrons to overcome the energy gap (Δ) to comply with Hund’s Rule. Therefore, electrons will fill the lower energy t2g orbitals completely before populating the higher energy eg orbitals. Conversely, a HS state occurs with weaker ligand fields and smaller orbital splitting. In this case the energy required to populate the higher levels is substantially less than the pairing energy and the electrons fill the orbitals according to Hund’s Rule by populating the higher energy orbitals before pairing with electrons in the lower lying orbitals. An example of a metal ion that can exist in either a LS or HS state is Fe3+ in an octahedral ligand field. Depending on the ligands that are coordinated to this complex the Fe3+ can attain a LS or a HS state, as in Figure 1.Spin crossover refers to the transitions between high to low, or low to high, spin states. This phenomenon is commonly observed with some first row transition metal complexes with a d4 through d7 electron configuration in an octahedral ligand geometry. Spin transition curves are a common representation of SCO phenomenon with the most commonly observed types depicted in Figure 2 in which γHS (the high-spin molar fraction) is plotted vs. T. The figure shows a gradual spin transition (left), an abrupt transition with hysteresis (middle) and a two-step transition (right). For a transition to be considered gradual, it typically takes place over a large temperature range, even up to several hundred K, whereas for a transition to be considered abrupt, it should take place within 10 K or less.These curves indicate that a spin transition has occurred in a metal complex as temperature changed. The gradual transition curve is an indication that not all metal centers within the complex are undergoing the transition at the same temperature. The abrupt spin change with hysteresis indicates a strong cooperativity, or “communication”, between neighboring metal complexes. In the latter case, the material is bistable and can exist in the two different spin states with a different range of external stimuli (temperature in this case) for the two phenomena, namely LS → HS and HS → LS. The two-step transition is relatively rare but is observed, for example, with dinuclear SCO complexes for which the spin transition in one metal center renders the transition in the second metal center less favorable.There are several types of spin crossover that can occur in a complex; some of them are light induced excited state spin trapping (LIESST), ligand-driven light induced spin change (LD-LISC), and charge transfer induced spin transition (CTIST).