Thermodynamics
... G is a measure of relative chemical stability for a phase We can determine G for any phase by measuring H and S for the reaction creating the phase from the elements We can then determine G at any T and P mathematically Most accurate if know how V and S vary with P and T • dV/dP is the coefficient ...
... G is a measure of relative chemical stability for a phase We can determine G for any phase by measuring H and S for the reaction creating the phase from the elements We can then determine G at any T and P mathematically Most accurate if know how V and S vary with P and T • dV/dP is the coefficient ...
How High the Spin? Allowed and Forbidden Spin States in
... other hand, presents a low-spin configuration with S = 1 (Figure 1 c),[4] which can be explained by the large splitting of the d orbitals due to an octahedral environment of strong-field ligands. In both of these cases, two different factors determine the magnitude of the d-orbital splitting and, he ...
... other hand, presents a low-spin configuration with S = 1 (Figure 1 c),[4] which can be explained by the large splitting of the d orbitals due to an octahedral environment of strong-field ligands. In both of these cases, two different factors determine the magnitude of the d-orbital splitting and, he ...
Learning objectives: Recall the reactivity of magnesium, zinc, iron
... Recall the reactivity of magnesium, zinc, iron, and tin from most to least reactive. Describe oxidation and reduction in terms of gain or loss of oxygen. Predict and explain displacement reactions between metals and metal salt solutions. Explain oxidation and reduction in terms of loss or ga ...
... Recall the reactivity of magnesium, zinc, iron, and tin from most to least reactive. Describe oxidation and reduction in terms of gain or loss of oxygen. Predict and explain displacement reactions between metals and metal salt solutions. Explain oxidation and reduction in terms of loss or ga ...
spectroscopic and antimicrobial studies of mixed ligand complexes
... creating similar chemical architectures, and determining functional. Reaction conditions for model systems is a process that allows the biological code of reactivity to be deciphered. In the past years the report on the crystal structures of type 3 copper enzymes (e.g. catechol oxidase, hemocyanins, ...
... creating similar chemical architectures, and determining functional. Reaction conditions for model systems is a process that allows the biological code of reactivity to be deciphered. In the past years the report on the crystal structures of type 3 copper enzymes (e.g. catechol oxidase, hemocyanins, ...
d-Block chemistry
... Box 28.5 Ferromagnetism and recording information (on p. 1293 in Chemistry3) The structure of Fe2O3 consists of a hexagonal close-packed array of oxide ions, with the iron ions in some of the octahedral sites. Given that oxide is a weak field ligand, determine the occupation of the t2g and eg orbita ...
... Box 28.5 Ferromagnetism and recording information (on p. 1293 in Chemistry3) The structure of Fe2O3 consists of a hexagonal close-packed array of oxide ions, with the iron ions in some of the octahedral sites. Given that oxide is a weak field ligand, determine the occupation of the t2g and eg orbita ...
Synthesis of Alum Lab
... (usually derived from a transition metal) joined by coordinate covalent bonds to molecules or anions called ligands. Complex ions can be cations or anions. Compounds composed of a complex ion and counter ions are coordinate compounds Hydrates are indicated by the dot and number of water molecules in ...
... (usually derived from a transition metal) joined by coordinate covalent bonds to molecules or anions called ligands. Complex ions can be cations or anions. Compounds composed of a complex ion and counter ions are coordinate compounds Hydrates are indicated by the dot and number of water molecules in ...
Picosecond X-ray Absorption Spectroscopy of a
... 2 ns and contributing 1.4 mA/bunch to the total ring current. A single bunch contributing 10 mA is placed within the center of the 100 ns empty section and is known as the “camshaft pulse”. The X-ray radiation from the camshaft pulse has a temporal width of 70 ps and can be easily singled out using ...
... 2 ns and contributing 1.4 mA/bunch to the total ring current. A single bunch contributing 10 mA is placed within the center of the 100 ns empty section and is known as the “camshaft pulse”. The X-ray radiation from the camshaft pulse has a temporal width of 70 ps and can be easily singled out using ...
Mössbauer Effect Studies of Europium-151 Complexes
... a weaker shielding of the s electrons in the 1,10phenanthroline complex, an effect which is clearly shown by the values of their isomer shifts. In Eu(H Sal);}-2 H 2 0, the phenyl ring can participate more in the derealization than in Na Eu[ (phth) 2 ]-4 H.,0. Therefore, it can be safely assumed that ...
... a weaker shielding of the s electrons in the 1,10phenanthroline complex, an effect which is clearly shown by the values of their isomer shifts. In Eu(H Sal);}-2 H 2 0, the phenyl ring can participate more in the derealization than in Na Eu[ (phth) 2 ]-4 H.,0. Therefore, it can be safely assumed that ...
Exam practice answers 6
... An example of cis–trans isomerism is the square planar structure of Ni(NH3)2Cl2 (any suitable example will get the marks e.g. cis–trans platin) has two different isomeric forms with the ammonia molecules or chloride ions either being on opposite sides of the complex ion (the trans form) or alon ...
... An example of cis–trans isomerism is the square planar structure of Ni(NH3)2Cl2 (any suitable example will get the marks e.g. cis–trans platin) has two different isomeric forms with the ammonia molecules or chloride ions either being on opposite sides of the complex ion (the trans form) or alon ...
Exam 3 Key - My Illinois State
... Labile. The substitution reaction occurs quickly, as observable with the color change. Inert species do not react quickly… if at all. b) Explain why you observed multiple color changes, not a single color change. The substitution of the hexacoordinated nickel does not occur in one step. One could im ...
... Labile. The substitution reaction occurs quickly, as observable with the color change. Inert species do not react quickly… if at all. b) Explain why you observed multiple color changes, not a single color change. The substitution of the hexacoordinated nickel does not occur in one step. One could im ...
IB Chemistry II Paper 2 Problem: 3/13 and 4 1. When concentrated
... NH3/ammonia has a higher boiling point than expected due to the hydrogen bonding between the molecules; Do not accept hydrogen bonding alone. ...
... NH3/ammonia has a higher boiling point than expected due to the hydrogen bonding between the molecules; Do not accept hydrogen bonding alone. ...
course outline - Midlands State University
... The course is a foundation for Chemistry in general upon which the understanding of Chemistry in general is based . It is especially important to have sufficient appreciation of the theories of bonding and how some atomic and molecular properties such as magnetism and electronic properties can be ex ...
... The course is a foundation for Chemistry in general upon which the understanding of Chemistry in general is based . It is especially important to have sufficient appreciation of the theories of bonding and how some atomic and molecular properties such as magnetism and electronic properties can be ex ...
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).