The bioinorganic chemistry of the ancient ocean: the co-evolution of
... were more abundant and Cu and Zn were scarcer in the Archean than in the modern ocean. Recent geochemical advances in sulfur isotopes now provide a rough history of sulfide chemistry on Earth [3]; here, we utilize this information to model the trace metal chemistry of the ancient oceans and compare ...
... were more abundant and Cu and Zn were scarcer in the Archean than in the modern ocean. Recent geochemical advances in sulfur isotopes now provide a rough history of sulfide chemistry on Earth [3]; here, we utilize this information to model the trace metal chemistry of the ancient oceans and compare ...
saitoICA2003
... were more abundant and Cu and Zn were scarcer in the Archean than in the modern ocean. Recent geochemical advances in sulfur isotopes now provide a rough history of sulfide chemistry on Earth [3]; here, we utilize this information to model the trace metal chemistry of the ancient oceans and compare ...
... were more abundant and Cu and Zn were scarcer in the Archean than in the modern ocean. Recent geochemical advances in sulfur isotopes now provide a rough history of sulfide chemistry on Earth [3]; here, we utilize this information to model the trace metal chemistry of the ancient oceans and compare ...
Cleavage of dinitrogen to yield a (t-BuPOCOP)molybdenum( ) nitridew Chem. Commun Cite this:
... Na/Hg under dinitrogen molecular nitrogen is cleaved to form [(t-BuPOCOP)Mo(I)(N)]. The origin of the N atom was confirmed using 15N2. Protonation of [(t-BuPOCOP)Mo(I)(N)] results in the formation of a neutral species in which it is proposed that the proton has added across the Mo–P bond. The catal ...
... Na/Hg under dinitrogen molecular nitrogen is cleaved to form [(t-BuPOCOP)Mo(I)(N)]. The origin of the N atom was confirmed using 15N2. Protonation of [(t-BuPOCOP)Mo(I)(N)] results in the formation of a neutral species in which it is proposed that the proton has added across the Mo–P bond. The catal ...
Cage Compounds with Main-Group Metals
... between the donors and the acceptors is directional. It is therefore important to consider some general features, which are dealt with in the next section. ...
... between the donors and the acceptors is directional. It is therefore important to consider some general features, which are dealt with in the next section. ...
Inorganic Chemistry 2 (033021) - Inorganic Reaction
... phosphine. The second is bend 3e NO to 1e NO, coordinate PMe3 and then lose CO in a rate limiting step that now contains both substrate and nucleophile in it. ...
... phosphine. The second is bend 3e NO to 1e NO, coordinate PMe3 and then lose CO in a rate limiting step that now contains both substrate and nucleophile in it. ...
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... that enforce a coordinatively unsaturated metal center. A low coordination number at the metal has emerged as an important feature, as tetrahedral and trigonal metal centers have π-symmetry orbitals that are not doubly occupied.19 Thus, even metals with a high formal d-electron count can form stabil ...
... that enforce a coordinatively unsaturated metal center. A low coordination number at the metal has emerged as an important feature, as tetrahedral and trigonal metal centers have π-symmetry orbitals that are not doubly occupied.19 Thus, even metals with a high formal d-electron count can form stabil ...
Contributions to Function in Blue Copper Proteins
... at 21.2 eV and HeII at 40.8 eV photons) can be ambiguous in peak assignments. The use of synchrotron radiation in allowing VEPES has revolutionized this method.12,19 Changes in the photon energy change the intensity of VEPES features, which through cross-section effects define the ligand and metal c ...
... at 21.2 eV and HeII at 40.8 eV photons) can be ambiguous in peak assignments. The use of synchrotron radiation in allowing VEPES has revolutionized this method.12,19 Changes in the photon energy change the intensity of VEPES features, which through cross-section effects define the ligand and metal c ...
Preparation of Cu Nanoclusters within Dendrimer Templates
... consisting of 2 amines and 2 other nitrogen- or oxygen-containing ligands.25-28 The binding between Cu2+ and dendrimer is pH dependent. Depending upon the solution conditions, however, the sorption of Cu2+ within the dendrimer is irreversible: the d-d transition band at 605 nm does not decrease sign ...
... consisting of 2 amines and 2 other nitrogen- or oxygen-containing ligands.25-28 The binding between Cu2+ and dendrimer is pH dependent. Depending upon the solution conditions, however, the sorption of Cu2+ within the dendrimer is irreversible: the d-d transition band at 605 nm does not decrease sign ...
Chapter 1 Structure and Bonding
... Several theories exist about how organisms became so stereoselective 1) Circularly polarized light is produced by some stars. a) Differential interaction with enantiomers by polarized light b) Destruction of one enantiomer by photoreactions results in enrichment of the other enantiomer c) Organisms ...
... Several theories exist about how organisms became so stereoselective 1) Circularly polarized light is produced by some stars. a) Differential interaction with enantiomers by polarized light b) Destruction of one enantiomer by photoreactions results in enrichment of the other enantiomer c) Organisms ...
Magnetic Exchange Coupling in Actinide
... exchange interactions, including multiuranium, uranium-lanthanide, uranium-transition metal, and uranium-radical species. Interpretation of the magnetic susceptibility data for compounds of this type is complicated by the combination of spin-orbit coupling and ligand-field effects arising for actini ...
... exchange interactions, including multiuranium, uranium-lanthanide, uranium-transition metal, and uranium-radical species. Interpretation of the magnetic susceptibility data for compounds of this type is complicated by the combination of spin-orbit coupling and ligand-field effects arising for actini ...
Introduction 1.1 Background
... As far as could be ascertained, no carbene complex has been reported with three different transition metal substituents that are all in electronic contact with the carbene carbon atom; a class of compounds we call carbene transition metal cluster compounds. Unlike the clusters defined by Cotton et a ...
... As far as could be ascertained, no carbene complex has been reported with three different transition metal substituents that are all in electronic contact with the carbene carbon atom; a class of compounds we call carbene transition metal cluster compounds. Unlike the clusters defined by Cotton et a ...
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... EDTA Titrations Metal Chelate Complexes – complexes formed between a Lewis acid and a Lewis base. Metals ions are Lewis acids, because they accept electrons from Lewis bases. When metal cations combine with Lewis bases, the resulting species is called a complex ion, and the base is called a ligand. ...
... EDTA Titrations Metal Chelate Complexes – complexes formed between a Lewis acid and a Lewis base. Metals ions are Lewis acids, because they accept electrons from Lewis bases. When metal cations combine with Lewis bases, the resulting species is called a complex ion, and the base is called a ligand. ...
The rôle of metals in amyloid aggregation. Experiments and
... and peptides switch from the physiological soluble configuration to a pathological fibrillar insoluble state. They comprise a heterogeneous group of diseases (more than 20) which are characterized by “plaques” formation [1]. Plaques are found to contain fairly large amount [2, 3] of transition metal ...
... and peptides switch from the physiological soluble configuration to a pathological fibrillar insoluble state. They comprise a heterogeneous group of diseases (more than 20) which are characterized by “plaques” formation [1]. Plaques are found to contain fairly large amount [2, 3] of transition metal ...
A Well-Dened Terminal Vanadium(III) Oxo Complex
... dz2 and (dxz, dyz) orbitals high in energy, and V−Npy σ-donor interactions destabilize both the dz2(axial pyridine) and dx2−y2 orbitals. On the basis of the simplified MO diagram shown in Scheme 1, a [VIII(O)]+ species would be expected to adopt a low-spin (S = 0) ground state upon the addition of an ...
... dz2 and (dxz, dyz) orbitals high in energy, and V−Npy σ-donor interactions destabilize both the dz2(axial pyridine) and dx2−y2 orbitals. On the basis of the simplified MO diagram shown in Scheme 1, a [VIII(O)]+ species would be expected to adopt a low-spin (S = 0) ground state upon the addition of an ...
Radical reactions with metal complexes in aqueous solutions
... these reactions in general follow the rate of ligand exchange for the specific metal complex in accord with the above mechanism. The majority of complexes containing metal carbon σ-bonds are unstable under physiological conditions and the products of their decomposition might cause deleterious biolo ...
... these reactions in general follow the rate of ligand exchange for the specific metal complex in accord with the above mechanism. The majority of complexes containing metal carbon σ-bonds are unstable under physiological conditions and the products of their decomposition might cause deleterious biolo ...
01-43 chimica.qxd
... Olefin metathesis is a child of strategy elaborated to obtain industry and was discovered by highly efficient, well-defined, accident. The reaction came to four-coordinate high oxidation Scheme 2. Plausible mechanism for olefin crosslight as a serendipitous outgrowth state alkylidene complexes metat ...
... Olefin metathesis is a child of strategy elaborated to obtain industry and was discovered by highly efficient, well-defined, accident. The reaction came to four-coordinate high oxidation Scheme 2. Plausible mechanism for olefin crosslight as a serendipitous outgrowth state alkylidene complexes metat ...
Stable gold(III) catalysts by oxidative addition of a carbon
... 5. The thermodynamic driving force for this reaction comes from the cleavage of the strained biphenylene C–C bond (bond dissociation energy, BDE 5 65.4 kcal mol21) via oxidative addition to Au(I), yielding two Au–C(Ar) bonds24,25. This unprecedented C–C bond cleavage by the linear IPrAu(I) cationic ...
... 5. The thermodynamic driving force for this reaction comes from the cleavage of the strained biphenylene C–C bond (bond dissociation energy, BDE 5 65.4 kcal mol21) via oxidative addition to Au(I), yielding two Au–C(Ar) bonds24,25. This unprecedented C–C bond cleavage by the linear IPrAu(I) cationic ...
Read Article - Roald Hoffmann
... Yu. T. Struchkov, V. N. Setkina, and D. N. Kursanov, J. Organomet. Chem., 136, 45 (1977); T. N. Salnikova, V. G. Andrianov, and Yu. T. Struchkov, Koord. Khim., 2, 707 (1976); (h) R. H. Fenn and J. H. Cross, J. Chem. SOC. A, 3312 (1971); S. Chaiwasie and R. H. Fenn, Acta Crystallogr., Sect. 8, 24, 52 ...
... Yu. T. Struchkov, V. N. Setkina, and D. N. Kursanov, J. Organomet. Chem., 136, 45 (1977); T. N. Salnikova, V. G. Andrianov, and Yu. T. Struchkov, Koord. Khim., 2, 707 (1976); (h) R. H. Fenn and J. H. Cross, J. Chem. SOC. A, 3312 (1971); S. Chaiwasie and R. H. Fenn, Acta Crystallogr., Sect. 8, 24, 52 ...
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... a Closed system, d8-toluene, 20 °C, t1/2 is the time required for the reaction to reach 50% of final constant ratio of 10 to 12. b Open driven condition, solvent 1,2,4-trichlorobenzene, 30 °C, 22 h, 1 mm Hg, yield based on isolated product. c Ligand A ) R,R,R-trifluoro-o-cresol. d Ligand B ) p-nitro ...
... a Closed system, d8-toluene, 20 °C, t1/2 is the time required for the reaction to reach 50% of final constant ratio of 10 to 12. b Open driven condition, solvent 1,2,4-trichlorobenzene, 30 °C, 22 h, 1 mm Hg, yield based on isolated product. c Ligand A ) R,R,R-trifluoro-o-cresol. d Ligand B ) p-nitro ...
The Nomenclature of Polyoxometalates: How To Connect a Name
... Trivial names were and are understood only by those working in the field. They say nothing about the composition; they say nothing about the structure. For example, paratungstate-A and paratungstate-B are completely different structurally speaking; their common feature is that they are both polyoxom ...
... Trivial names were and are understood only by those working in the field. They say nothing about the composition; they say nothing about the structure. For example, paratungstate-A and paratungstate-B are completely different structurally speaking; their common feature is that they are both polyoxom ...
Complexes. X-ray Structure of Rh1[C6H,(CH2NMe2),-o ,o`
... twice washed with pentane (2 mL) affording pale yellow [RhOMe(COD)I2(28 mg, 80%; ‘H NMR (CDC13)6 1.65 (m, 8 H), 2.4 (m, 8 H), 2.66 (6 H), 3.53 (m, 8 H); ref 10, 6 1.63, 2.47, 2.67, and 3.55, respectively). The combined pentane washings, evaporated to dryness, afforded m-(Me2NCH2)2CsH4contaminated wi ...
... twice washed with pentane (2 mL) affording pale yellow [RhOMe(COD)I2(28 mg, 80%; ‘H NMR (CDC13)6 1.65 (m, 8 H), 2.4 (m, 8 H), 2.66 (6 H), 3.53 (m, 8 H); ref 10, 6 1.63, 2.47, 2.67, and 3.55, respectively). The combined pentane washings, evaporated to dryness, afforded m-(Me2NCH2)2CsH4contaminated wi ...
Synthesis of Molybdenum Alkylidene Complexes That Contain the 2,6-Dimesitylphenylimido Ligand
... imido species, Mo(NAr)(N-t-Bu)Cl2(DME), and that Mo(NAr)(N-t-Bu)(CH2CMe2R)2 (R = Me or Ph) reacts with pentafluorophenol to give exclusively Mo(NAr)(CHCMe2R)(OC6F5)2.7 Ar*NH2 was prepared by the reported method.5b As shown in Scheme 1, addition of LiNHAr* to Mo(N-t-Bu)2Cl2(dme) yielded intermediate M ...
... imido species, Mo(NAr)(N-t-Bu)Cl2(DME), and that Mo(NAr)(N-t-Bu)(CH2CMe2R)2 (R = Me or Ph) reacts with pentafluorophenol to give exclusively Mo(NAr)(CHCMe2R)(OC6F5)2.7 Ar*NH2 was prepared by the reported method.5b As shown in Scheme 1, addition of LiNHAr* to Mo(N-t-Bu)2Cl2(dme) yielded intermediate M ...
Nickel complexes of a diphosphine-ketone ligand: oxidation
... metals instead are being made. Recently, the hydrogenation of CO2 has been reported catalysed by an organometallic cobalt complex[3]. The process would be more attractive using the more abundant and less costly first-row transition metal based complexes. One of the possibly useful metals for this ro ...
... metals instead are being made. Recently, the hydrogenation of CO2 has been reported catalysed by an organometallic cobalt complex[3]. The process would be more attractive using the more abundant and less costly first-row transition metal based complexes. One of the possibly useful metals for this ro ...
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.