Intermetal Oxygen, Sulfur, Selenium, and Nitrogen Atom Transfer
... Use of oxygen in analogous work was primarily limited to discussions involving water as a bridging species. 28 Oxygen atom transfer processes generally involve terminal metal oxo complexes as the oxidant. The terminal oxo ligand is typically found in complexes in which the metal exists in a high for ...
... Use of oxygen in analogous work was primarily limited to discussions involving water as a bridging species. 28 Oxygen atom transfer processes generally involve terminal metal oxo complexes as the oxidant. The terminal oxo ligand is typically found in complexes in which the metal exists in a high for ...
Manganese-Catalyzed Carbonylation of Alkyl Iodides
... Palladium Catalyzed Cross-Coupling of Aryl Halides with Zirconocene-Benzyne Complexes and Manganese Catalyzed Carbonylation of Alkyl Halides ...
... Palladium Catalyzed Cross-Coupling of Aryl Halides with Zirconocene-Benzyne Complexes and Manganese Catalyzed Carbonylation of Alkyl Halides ...
Perspectives on How Nature Employs the Principles of
... in H2 complexes) for it to be observable under ambient conditions: e.g., in regard to the mechanism of methane monooxygenase. Methane C-H bond activation may not even occur at the dinuclear Fe sites in the latter but rather at the bridging oxo ligands, involving either radical or concerted mechanism ...
... in H2 complexes) for it to be observable under ambient conditions: e.g., in regard to the mechanism of methane monooxygenase. Methane C-H bond activation may not even occur at the dinuclear Fe sites in the latter but rather at the bridging oxo ligands, involving either radical or concerted mechanism ...
Read Article - Roald Hoffmann
... of the bridging groups; (3) direct bonding or antibonding overlap of primarily metal-centered orbitals. The mix of these contributions is variable. In many cases, especially those in which compounds are compared which differ from each other only by one or two electrons, the last effect is important. ...
... of the bridging groups; (3) direct bonding or antibonding overlap of primarily metal-centered orbitals. The mix of these contributions is variable. In many cases, especially those in which compounds are compared which differ from each other only by one or two electrons, the last effect is important. ...
Transition metal-catalysed hydrogen transfer processes for C C and C N
... Abstract This thesis focusses on synthetic studies and mechanistic investigations of reactions involving hydrogen-transfer processes. In the first part, the development of an efficient method for the synthesis of -hydroxy ketones (aldols) and -amino ketones (Mannich products) from allylic alcoh ...
... Abstract This thesis focusses on synthetic studies and mechanistic investigations of reactions involving hydrogen-transfer processes. In the first part, the development of an efficient method for the synthesis of -hydroxy ketones (aldols) and -amino ketones (Mannich products) from allylic alcoh ...
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 ...
4 Investigation of substituent effect on
... A.; Frenking, G.; J. Am. Chem. Soc. 2008, 130, 16646, (c) Krapp, A.; Pandey, K.K.; Frenking,G. J. Am. Chem. Soc. 2007, 129, 7596, (d) Frenking, G.; Sola, M.; Vyboishchikov, S.F. J. Organomet. Chem. 2005, 690, 6178, (e) Sierra, M.A.; Fernández, I.; Cossío, F.P. Chem. Commun. 2008, 4761, (f) Lage, M.L ...
... A.; Frenking, G.; J. Am. Chem. Soc. 2008, 130, 16646, (c) Krapp, A.; Pandey, K.K.; Frenking,G. J. Am. Chem. Soc. 2007, 129, 7596, (d) Frenking, G.; Sola, M.; Vyboishchikov, S.F. J. Organomet. Chem. 2005, 690, 6178, (e) Sierra, M.A.; Fernández, I.; Cossío, F.P. Chem. Commun. 2008, 4761, (f) Lage, M.L ...
Synthesis of alternating hydroxy-and methyl
... was recrystallized twice from petroleum ether at -30 OC yielding 100 mg of pure 2 in the form of dark thin plates. (5) Attempts to grow single crystals suitable for X-ray crystallography have thus far been unsuccessful. ...
... was recrystallized twice from petroleum ether at -30 OC yielding 100 mg of pure 2 in the form of dark thin plates. (5) Attempts to grow single crystals suitable for X-ray crystallography have thus far been unsuccessful. ...
Beyond Conventional N-Heterocyclic Carbenes
... the concept of heterocyclic carbene ligands that are not stabilized by two adjacent heteroatoms, as in Arduengo-type carbenes, and also not necessarily with heteroatoms placed in a position R to the carbene carbon was revived by a serendipitous discovery of C4 bonding in imidazolylidenes.6 The large ...
... the concept of heterocyclic carbene ligands that are not stabilized by two adjacent heteroatoms, as in Arduengo-type carbenes, and also not necessarily with heteroatoms placed in a position R to the carbene carbon was revived by a serendipitous discovery of C4 bonding in imidazolylidenes.6 The large ...
High-valent metal-oxo complexes generated in catalytic oxidation
... (Scheme 4) [47]. From the rate constants of cumene and cumene-d12, the kinetic isotope effect (KIE) was determined to be 12 for the H-atom abstraction step [47]. In the first step, H-atom transfer from cumene to 4 occurs to produce cumyl radical and a Ru(III)-hydroxo complex. The oxygen rebound betw ...
... (Scheme 4) [47]. From the rate constants of cumene and cumene-d12, the kinetic isotope effect (KIE) was determined to be 12 for the H-atom abstraction step [47]. In the first step, H-atom transfer from cumene to 4 occurs to produce cumyl radical and a Ru(III)-hydroxo complex. The oxygen rebound betw ...
- Opus
... remaining four acac groups are bidentate with respect to furnace. The powder obtained from complex (1) was nickel but have an additional bridging bond to barium analysed using SEM/EDX and X-ray powder diffraction, through one of the two oxygen centers. The “bite” angles while the powder obtained fro ...
... remaining four acac groups are bidentate with respect to furnace. The powder obtained from complex (1) was nickel but have an additional bridging bond to barium analysed using SEM/EDX and X-ray powder diffraction, through one of the two oxygen centers. The “bite” angles while the powder obtained fro ...
The synthesis and properties of solution processable red-emitting phosphorescent dendrimers Materials Chemistry
... to the biphenyl units in the dendrons. The red shift in the ligand absorption of G1-BTP 7 relative to BTP is due to the fact that the first phenyl ring of the dendron is in conjugation with the BTP moiety. For the symmetric iridium dendrimer 9 the complexation of the dendron to the metal cation make ...
... to the biphenyl units in the dendrons. The red shift in the ligand absorption of G1-BTP 7 relative to BTP is due to the fact that the first phenyl ring of the dendron is in conjugation with the BTP moiety. For the symmetric iridium dendrimer 9 the complexation of the dendron to the metal cation make ...
The Oxide Fluoride Chemistry of Bromine, Selenium and Sulphur
... the neutral element decreases. However, as the oxidation state of an element increases, shielding of the nuclear charge becomes less effective and the element becomes less polarisiable or more electronegative. As a consequence, a large majority of the highest oxidation state compounds of the element ...
... the neutral element decreases. However, as the oxidation state of an element increases, shielding of the nuclear charge becomes less effective and the element becomes less polarisiable or more electronegative. As a consequence, a large majority of the highest oxidation state compounds of the element ...
EDTA - MOTM - The EndoExperience
... A number of metal-EDTA complexes have been reported to have the EDTA acting as a pentadentate ligand (only five sites on EDTA bind, one carboxylic group does NOT). A water molecule or another ligand is in the sixth site, so the complexes are still octahedral in geometry. So let's examine the formati ...
... A number of metal-EDTA complexes have been reported to have the EDTA acting as a pentadentate ligand (only five sites on EDTA bind, one carboxylic group does NOT). A water molecule or another ligand is in the sixth site, so the complexes are still octahedral in geometry. So let's examine the formati ...
reactions of some transition metal ions cobalt
... In volumetric analysis it must be acidified with dilute sulphuric acid as MnO4¯ is powerful enough to oxidise the chloride ions in hydrochloric acid. It is used to estimate iron(II), hydrogen peroxide, ethanedioic (oxalic) acid and ethanedioate (oxalate) ions. The last two titrations are carried out ...
... In volumetric analysis it must be acidified with dilute sulphuric acid as MnO4¯ is powerful enough to oxidise the chloride ions in hydrochloric acid. It is used to estimate iron(II), hydrogen peroxide, ethanedioic (oxalic) acid and ethanedioate (oxalate) ions. The last two titrations are carried out ...
Photochemistry and photophysics of antimony (III) hyper porphyrins
... dinated. However, reports on light-induced redox reactions, changing the formal oxidation state of the central atom, are still rare in the field of metalloporphyrin photochemistry.15J6 The preponderance of observations is limited to chromium, manganese, and iron porphyrins,17 which display conspicuo ...
... dinated. However, reports on light-induced redox reactions, changing the formal oxidation state of the central atom, are still rare in the field of metalloporphyrin photochemistry.15J6 The preponderance of observations is limited to chromium, manganese, and iron porphyrins,17 which display conspicuo ...
Bis-Silylated Lithium Aryl Amidinates: Synthesis, Characterization
... of the coordination mode and aggregation degree between the lithium metal and a certain amidinate motif is highly affected by the presence of additional ligands or donor solvents and by the substitution of the amidinate backbone. Thus, in the presence of chelating donors such as TMEDA, the η2 chelat ...
... of the coordination mode and aggregation degree between the lithium metal and a certain amidinate motif is highly affected by the presence of additional ligands or donor solvents and by the substitution of the amidinate backbone. Thus, in the presence of chelating donors such as TMEDA, the η2 chelat ...
Organic Chemistry II
... Alkyl Halides We did talk about halo-alkanes (called alkyl halides) which are alkanes with a halogen attached. These molecules do, in fact, have polar bonds: C-Br, C-I, C-Cl are all polar bonds. Carbon is slightly positive, the halogen is slightly negative. ...
... Alkyl Halides We did talk about halo-alkanes (called alkyl halides) which are alkanes with a halogen attached. These molecules do, in fact, have polar bonds: C-Br, C-I, C-Cl are all polar bonds. Carbon is slightly positive, the halogen is slightly negative. ...
Aron Janine 1986
... coenzyme, adenosylcobalamin, and in methyl, ethyl and cyclobutylcobalamins have been determined in aqueous solution at 96 °C. The t!£ values increase (rates decrease) in the following ligand order: ethyl (ca. 9 min) < cyclobutyl (ca. 75 min) < adeno^yl (c*». '80 min) < methy) (ca. 80 hrs). These val ...
... coenzyme, adenosylcobalamin, and in methyl, ethyl and cyclobutylcobalamins have been determined in aqueous solution at 96 °C. The t!£ values increase (rates decrease) in the following ligand order: ethyl (ca. 9 min) < cyclobutyl (ca. 75 min) < adeno^yl (c*». '80 min) < methy) (ca. 80 hrs). These val ...
Functional Mimics of Superoxide Dismutase Enzymes as
... cannot be directly determined. However, this method may indicate whether a compound is an SOD mimic at lower levels of activity than the direct methods. It is important to verify, however, that the compound being tested is not participating in a redox short circuit, i.e., simply reducing the indicat ...
... cannot be directly determined. However, this method may indicate whether a compound is an SOD mimic at lower levels of activity than the direct methods. It is important to verify, however, that the compound being tested is not participating in a redox short circuit, i.e., simply reducing the indicat ...
coord_chem_2
... • The oxidation state of the metal centre is given by a Roman numeral. • If the complex is an anion the ending –ate is attached to the name of the metal. ...
... • The oxidation state of the metal centre is given by a Roman numeral. • If the complex is an anion the ending –ate is attached to the name of the metal. ...
CE4501 Environmental Engineering Chemical Processes
... ligand such that only 0.25 mM of hardness remains: CT-Ca = 3x10-3 M = [Ca2+] + [CaL-] The mass balance above assumes that the carbonato complex and the ternary complex with NTA (CaL24) are unimportant. We will have to verify those assumptions later. NTA is a triprotic acid with pKa’s of 2.0, 2.94 an ...
... ligand such that only 0.25 mM of hardness remains: CT-Ca = 3x10-3 M = [Ca2+] + [CaL-] The mass balance above assumes that the carbonato complex and the ternary complex with NTA (CaL24) are unimportant. We will have to verify those assumptions later. NTA is a triprotic acid with pKa’s of 2.0, 2.94 an ...
Metal carbonyl
Metal carbonyls are coordination complexes of transition metals with carbon monoxide ligands. Metal carbonyls are useful in organic synthesis and as catalysts or catalyst precursors in homogeneous catalysis, such as hydroformylation and Reppe chemistry. In the Mond process, nickel carbonyl is used to produce pure nickel. In organometallic chemistry, metal carbonyls serve as precursors for the preparation of other organometalic complexes.Metal carbonyls are toxic by skin contact, inhalation or ingestion, in part because of their ability to carbonylate hemoglobin to give carboxyhemoglobin, which prevents the binding of O2.