214. - Materials and Process Simulation Center
... C1-like GVB orbital is nearly pure p character (95%) with very little metal character (3%). In summary all complexes that would be described as Mt(I1) in the normal oxidation state formalism are unoxidized and have s1d9character on the metal. Thus, oxidative addition of these metals to H-H, H-C, and ...
... C1-like GVB orbital is nearly pure p character (95%) with very little metal character (3%). In summary all complexes that would be described as Mt(I1) in the normal oxidation state formalism are unoxidized and have s1d9character on the metal. Thus, oxidative addition of these metals to H-H, H-C, and ...
Chapter 23 Metals and Metallurgy
... • Electron-sea model does not explain observed trends in melting point, boiling point, heat of fusion, etc. Suggests these properties should increase with increasing number of valence electrons. ...
... • Electron-sea model does not explain observed trends in melting point, boiling point, heat of fusion, etc. Suggests these properties should increase with increasing number of valence electrons. ...
Carbon dioxide and metal centres: from reactions
... The first crystal structures of urease were published by Karplus et al. in 1995 [25]. Refinement and comparison of 14 crystal structures up to now with a resolution of 2.2 Å and better reflect a quite precise picture of their structure. The active part consists of a binuclear Ni(II) unit whose coor ...
... The first crystal structures of urease were published by Karplus et al. in 1995 [25]. Refinement and comparison of 14 crystal structures up to now with a resolution of 2.2 Å and better reflect a quite precise picture of their structure. The active part consists of a binuclear Ni(II) unit whose coor ...
New inorganic iridium(III) complexes for photonic applications
... just below the conducting band and thus can be easily raised into the conducting band resulting in electrical current. These energy levels are called donor levels. The process of adding an electron in this way is called negative doping or n-doping of silicon and there are no holes created in the val ...
... just below the conducting band and thus can be easily raised into the conducting band resulting in electrical current. These energy levels are called donor levels. The process of adding an electron in this way is called negative doping or n-doping of silicon and there are no holes created in the val ...
Reaction of Nitrogen Chelates with the [Rh2]4+ Core: Bis
... (12) Glowiak, T.; Pasternak, H.; Pruchnik, F. Acta Crystallogr. 1987, C43, ...
... (12) Glowiak, T.; Pasternak, H.; Pruchnik, F. Acta Crystallogr. 1987, C43, ...
Improved Synthesis of Seven-Coordinate Molybdenum( I I) and
... and the reaction was refluxed for 12 h. The methanol and any free isocyanide was removed under reduced pressure. The resultant solid was p h o t o c h e m i ~ a l l yconverted ~ ~ ~ ~ ~ to [W(CN-tC&)6I]I and purified as described in the synthesis of [Mo(CNt-C4Hg)61]Iabove. A total of 0.64 g of [W(CN ...
... and the reaction was refluxed for 12 h. The methanol and any free isocyanide was removed under reduced pressure. The resultant solid was p h o t o c h e m i ~ a l l yconverted ~ ~ ~ ~ ~ to [W(CN-tC&)6I]I and purified as described in the synthesis of [Mo(CNt-C4Hg)61]Iabove. A total of 0.64 g of [W(CN ...
Inorganic Chemistry, Second Edition
... The familiar planetary model of the atom was proposed by Rutherford in 1912 following experiments by Geiger and Marsden showing that nearly all the mass of an atom was concentrated in a positively charged nucleus. Negatively charged electrons are attracted to the nucleus by the electrostatic force a ...
... The familiar planetary model of the atom was proposed by Rutherford in 1912 following experiments by Geiger and Marsden showing that nearly all the mass of an atom was concentrated in a positively charged nucleus. Negatively charged electrons are attracted to the nucleus by the electrostatic force a ...
Photochemical and Photophysical Properties of Tetranuclear and
... interesting is the prediction that excited states (ES) for which there is a substantially increased electronic population in metal ns or np orbitals should have enhanced metal-metal bonding. The result would be excited states significantly distorted from the ground states in a manner that should hav ...
... interesting is the prediction that excited states (ES) for which there is a substantially increased electronic population in metal ns or np orbitals should have enhanced metal-metal bonding. The result would be excited states significantly distorted from the ground states in a manner that should hav ...
A SOLUTION AND SOLID STATE STUDY OF VANADIUM
... Vanadium is an early first-row transition metal that is known for the beautiful coloured compounds that it forms in a wide range of oxidation states. In high oxidation states, vanadium is very oxophilic whilst at low oxidation states, π-donating ligands are preferred. It is the only element in the p ...
... Vanadium is an early first-row transition metal that is known for the beautiful coloured compounds that it forms in a wide range of oxidation states. In high oxidation states, vanadium is very oxophilic whilst at low oxidation states, π-donating ligands are preferred. It is the only element in the p ...
Chapter 1 Introduction - Heriot
... neutral or anionic. The chemistry of boranes was first studied systematically by Alfred Stock and his research group beginning in 1912 and continuing for almost 25 years.4 Stock developed the glass vacuum line and techniques for using it, which enabled him to synthesise and characterise these novel ...
... neutral or anionic. The chemistry of boranes was first studied systematically by Alfred Stock and his research group beginning in 1912 and continuing for almost 25 years.4 Stock developed the glass vacuum line and techniques for using it, which enabled him to synthesise and characterise these novel ...
From nucleotides to ribozymes — A comparison of their metal ion
... and therefore might be used to regulate other cellular reactions. Examples exist where the metal ion specificity of naturally occurring ribozymes can be switched by appropriate mutations within the catalytic core. One such example encompasses group I introns. Usually, these large ribozymes have a st ...
... and therefore might be used to regulate other cellular reactions. Examples exist where the metal ion specificity of naturally occurring ribozymes can be switched by appropriate mutations within the catalytic core. One such example encompasses group I introns. Usually, these large ribozymes have a st ...
Experimental and Theoretical EPR Study of JahnTeller-
... such a scale [συ⊥, συ∥] are related to those on a field scale by the g-values, with συ⊥/συ∥ = g⊥σB⊥/g∥σB∥. The result is συ⊥/συ∥ ~ 1, and thus the spectra and simulations give no indication that the g-tensor has any rhombic character; the maximum rhombicity that could be accommodated without introdu ...
... such a scale [συ⊥, συ∥] are related to those on a field scale by the g-values, with συ⊥/συ∥ = g⊥σB⊥/g∥σB∥. The result is συ⊥/συ∥ ~ 1, and thus the spectra and simulations give no indication that the g-tensor has any rhombic character; the maximum rhombicity that could be accommodated without introdu ...
Hydrolysis Reactions
... Most transition metal hydroxides are amphoteric and behave in this way. When sodium hydroxide solution is added to a solution of a chromium(III) salt, a green precipitate of chromium(III) hydroxide is formed. This re-dissolves in excess to give a dark green solution. The behaviour of chromium(III) i ...
... Most transition metal hydroxides are amphoteric and behave in this way. When sodium hydroxide solution is added to a solution of a chromium(III) salt, a green precipitate of chromium(III) hydroxide is formed. This re-dissolves in excess to give a dark green solution. The behaviour of chromium(III) i ...
Preparation and structural characterization of group 1 metal
... the phenolato oxygen atoms. Compound bis-(3,5-di-tertbutyl-2-hydroxyphenyl)phenylphosphine (H2[OPO]) is a suitable ligand precursor available from the literature [30]. To begin with, we report in this contribution the preparation and structural characterization of [OPO]2 with respect to group 1 meta ...
... the phenolato oxygen atoms. Compound bis-(3,5-di-tertbutyl-2-hydroxyphenyl)phenylphosphine (H2[OPO]) is a suitable ligand precursor available from the literature [30]. To begin with, we report in this contribution the preparation and structural characterization of [OPO]2 with respect to group 1 meta ...
Nitrogen Complexes of the Platinum Metals
... but the corresponding bromide is less easy and the iodide is too unstable to be obtained as is the thiocyanate, although the ...
... but the corresponding bromide is less easy and the iodide is too unstable to be obtained as is the thiocyanate, although the ...
Functional Mimics of Superoxide Dismutase Enzymes as
... (aqueous buffer:DMSO, ∼20:1). Unlike the other methods, the initial concentration of superoxide can be very high compared to the putative catalysts being evaluated (>1000:1). With this stopped-flow method, if a pure first-order decay of superoxide is obtained (as monitored by the disappearance of su ...
... (aqueous buffer:DMSO, ∼20:1). Unlike the other methods, the initial concentration of superoxide can be very high compared to the putative catalysts being evaluated (>1000:1). With this stopped-flow method, if a pure first-order decay of superoxide is obtained (as monitored by the disappearance of su ...
π-Arene/Cation Structure and Bonding. Solvation
... not easily recognized in nonpolar arenes because they are disguised as quadrupoles,8 are important in defining the structures of π-π interactions. Particular success has been encountered with porphyrins.9 In the π interactions of arenes with soft, main group metals such as Ag+ and Tl+, some degree o ...
... not easily recognized in nonpolar arenes because they are disguised as quadrupoles,8 are important in defining the structures of π-π interactions. Particular success has been encountered with porphyrins.9 In the π interactions of arenes with soft, main group metals such as Ag+ and Tl+, some degree o ...
BIOINORGANIC CHEMISTRY A Short Course
... aconitase, an enzyme that contains an [Fe4 S4 ]2þ cluster and catalyzes the isomerization of citrate and isocitrate. The isomerization is a key reaction in the Kreb’s cycle. In aconitase, one cluster iron binds citrate at the active site during the catalytic cycle. Liver alcohol dehydrogenase (LADH) ...
... aconitase, an enzyme that contains an [Fe4 S4 ]2þ cluster and catalyzes the isomerization of citrate and isocitrate. The isomerization is a key reaction in the Kreb’s cycle. In aconitase, one cluster iron binds citrate at the active site during the catalytic cycle. Liver alcohol dehydrogenase (LADH) ...
REACTIONS OF HEXAAQUA METAL IONS WITH HYDROXIDE IONS
... It also doesn't matter where you start from either - whether, for example, you add acid to an ionic complex like [Cr(OH)6]3-, or a neutral one like [Fe(H2O)4(OH)2]. You will know that the [Fe(H2O)4(OH)2] is a dirty green precipitate. When you add the hydrogen ions back to it, it will revert to the v ...
... It also doesn't matter where you start from either - whether, for example, you add acid to an ionic complex like [Cr(OH)6]3-, or a neutral one like [Fe(H2O)4(OH)2]. You will know that the [Fe(H2O)4(OH)2] is a dirty green precipitate. When you add the hydrogen ions back to it, it will revert to the v ...
Linkage Isomerization in Heme-NOx Compounds: Understanding
... the NO group to the metal center, as shown at the bottom right of Figure 2. Such a binding mode was demonstrated by Coppens for a metastable state of sodium nitroprusside3 and for a metastable state of CpNi(NO) (Cp = η5-cyclopentadienyl anion).6 This side-on NO geometry has also been determined in X ...
... the NO group to the metal center, as shown at the bottom right of Figure 2. Such a binding mode was demonstrated by Coppens for a metastable state of sodium nitroprusside3 and for a metastable state of CpNi(NO) (Cp = η5-cyclopentadienyl anion).6 This side-on NO geometry has also been determined in X ...
Low-temperature lifetimes of metastable high
... materials, the thermal spin transition is gradual corresponding to a Boltzmann distribution between the two vibronic manifolds. In neat spin-crossover compounds, transition curves tend to be more abrupt and may occur as first order phase transitions with a hysteresis. Such a cooperative behaviour is ...
... materials, the thermal spin transition is gradual corresponding to a Boltzmann distribution between the two vibronic manifolds. In neat spin-crossover compounds, transition curves tend to be more abrupt and may occur as first order phase transitions with a hysteresis. Such a cooperative behaviour is ...
無投影片標題
... The d-block metals are comparatively small, and the metallic atoms are closely packed in the metallic lattice. Besides, both the 3d and 4s electrons of the d-block metals participate in metallic bondingAnswer by delocalizing into the electron sea. The strength of metallic bond in these metals is thu ...
... The d-block metals are comparatively small, and the metallic atoms are closely packed in the metallic lattice. Besides, both the 3d and 4s electrons of the d-block metals participate in metallic bondingAnswer by delocalizing into the electron sea. The strength of metallic bond in these metals is thu ...
Inorganic Chemistry of LanthanideIV:
... being used in infrared filters and as a replacement for radioactive thorium dioxide in incandescent mantles. While cerium dioxide is transparent for visible light, it is a strong ultraviolet light absorber. Thus it has been envisaged as a prospective replacement for ZnO and TiO 2 in sunscreens, alth ...
... being used in infrared filters and as a replacement for radioactive thorium dioxide in incandescent mantles. While cerium dioxide is transparent for visible light, it is a strong ultraviolet light absorber. Thus it has been envisaged as a prospective replacement for ZnO and TiO 2 in sunscreens, alth ...
The highly preorganized ligands 1,10-Phenanthroline
... attachment to gadolinium, leaving one available coordination site for a water molecule This is of importance because the ability to shift the MRI signal is a function of the number of water molecules directly attached to gadolinium.8 An ideal contrast agent would not have as many points of attachmen ...
... attachment to gadolinium, leaving one available coordination site for a water molecule This is of importance because the ability to shift the MRI signal is a function of the number of water molecules directly attached to gadolinium.8 An ideal contrast agent would not have as many points of attachmen ...
Ligand
In coordination chemistry, a ligand (/lɪɡənd/) is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from covalent to ionic. Furthermore, the metal-ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic ""ligand.""Metals and metalloids are bound to ligands in virtually all circumstances, although gaseous ""naked"" metal ions can be generated in high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection is a critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environmental chemistry.Ligands are classified in many ways like : their charge, their size (bulk), the identity of the coordinating atom(s), and the number of electrons donated to the metal (denticity or hapticity). The size of a ligand is indicated by its cone angle.