Computational Evidence of the Importance of Substituent Bulk on
... Following their initial discovery1 and subsequent categorization,2 agostic interactions have been found to be extremely common, provided a metal has a low-lying empty valence orbital. In fact, there has been little scrutiny of what factors can assist in stabilizing agostic interactions. Every comple ...
... Following their initial discovery1 and subsequent categorization,2 agostic interactions have been found to be extremely common, provided a metal has a low-lying empty valence orbital. In fact, there has been little scrutiny of what factors can assist in stabilizing agostic interactions. Every comple ...
19F NMR in organometallic chemistry Applications of fluorinated aryls
... (ii) the spin–spin interactions of 19 F nuclei are also larger than the corresponding interactions between protons; (iii) often the 19 F–19 F coupling is transmitted not only through bonding electrons, but also by a direct through space mechanism; (iv) solvent effects influence 19 F resonances far m ...
... (ii) the spin–spin interactions of 19 F nuclei are also larger than the corresponding interactions between protons; (iii) often the 19 F–19 F coupling is transmitted not only through bonding electrons, but also by a direct through space mechanism; (iv) solvent effects influence 19 F resonances far m ...
8 Microbial Leaching of Metals - Wiley-VCH
... elements such as, e.g., Cd or Zn might be chemically mobilized already during acidification. MWI fly ash contains reduced copper species (chalcocite {Cu2S} or cuprite {Cu2O}) whereas zinc and others are present in their fully oxidized forms (BROMBACHER et al., 1998). Therefore, copper release from f ...
... elements such as, e.g., Cd or Zn might be chemically mobilized already during acidification. MWI fly ash contains reduced copper species (chalcocite {Cu2S} or cuprite {Cu2O}) whereas zinc and others are present in their fully oxidized forms (BROMBACHER et al., 1998). Therefore, copper release from f ...
PDF File
... critical to obtain an affinity of the rescuing Mn2⫹ that is not perturbed by the modification. Therefore, the rescue is carried out under conditions such that the substrate bearing the modification is not bound within the active site in the starting ground state. If the starting ground state is the ...
... critical to obtain an affinity of the rescuing Mn2⫹ that is not perturbed by the modification. Therefore, the rescue is carried out under conditions such that the substrate bearing the modification is not bound within the active site in the starting ground state. If the starting ground state is the ...
Cyclam ``capa` POT.4` to ``capa` POT.3` denticity change
... targeting improvement by the judicious choice of the biomolecule (an antibody, for instance). With this aim, our first results were achieved with trans-[RuCl(L)(1-(3-propylammonium)cyclam)]n+ (L ) Cl-, H2O (tfms ) trifluoromethanesulfonate))29 which has a pendant amino group that can be used as a li ...
... targeting improvement by the judicious choice of the biomolecule (an antibody, for instance). With this aim, our first results were achieved with trans-[RuCl(L)(1-(3-propylammonium)cyclam)]n+ (L ) Cl-, H2O (tfms ) trifluoromethanesulfonate))29 which has a pendant amino group that can be used as a li ...
Copper di-imine complexes: Structures and catalytic activity
... understanding of the active catalyst structures and catalytic reactions turned out to be considerably important for developing new highly active catalysts. In chemical pulp bleaching, lignin is usually transformed to more soluble fragments by the oxidation of phenolic, alcoholic and unsaturated lign ...
... understanding of the active catalyst structures and catalytic reactions turned out to be considerably important for developing new highly active catalysts. In chemical pulp bleaching, lignin is usually transformed to more soluble fragments by the oxidation of phenolic, alcoholic and unsaturated lign ...
Chemistry of Ti(OiPr)Cl3 with Chloride
... distance between the titanium metal and the chloride trans to the isopropoxide is extremely long at 2.581(3) Å (Ti-Cl(3)). This Ti-Cl distance is much longer than the average distance between the titanium metal and the cis chlorides at 2.375 Å. Moreover, this distance is comparable to or even longer ...
... distance between the titanium metal and the chloride trans to the isopropoxide is extremely long at 2.581(3) Å (Ti-Cl(3)). This Ti-Cl distance is much longer than the average distance between the titanium metal and the cis chlorides at 2.375 Å. Moreover, this distance is comparable to or even longer ...
CARBON-HYDROGEN-TRANSITION METAL BONDS
... receive the two electrons of the C-H bond. It is to be presumed that this orbital will be essentially of d-character for transition metal compounds. The orbital should be a very good acceptor and the energy and disposition should approach that of the C-H bonding electrons as far as possible. If ther ...
... receive the two electrons of the C-H bond. It is to be presumed that this orbital will be essentially of d-character for transition metal compounds. The orbital should be a very good acceptor and the energy and disposition should approach that of the C-H bonding electrons as far as possible. If ther ...
PDF File
... provided functional evidence for a network of transition state interactions within the Tetrahymena ribozyme active site, involving five substrate atoms interacting with three metal ions and additional hydrogen-bonding interactions (Figure 1). According to the resultant model, metal ions coordinate t ...
... provided functional evidence for a network of transition state interactions within the Tetrahymena ribozyme active site, involving five substrate atoms interacting with three metal ions and additional hydrogen-bonding interactions (Figure 1). According to the resultant model, metal ions coordinate t ...
COORDINATION COMPLEXES OF COBALT
... In this lab, you will synthesize two cobalt coordination complexes, [Co(NH3)5(NO2)]Cl2 and [Co(NH3)5(ONO)]Cl2, and investigate linkage isomerism. Linkage isomerism involves ligands that are capable of bonding through one type of atom in one situation and another type of atom in a different situation ...
... In this lab, you will synthesize two cobalt coordination complexes, [Co(NH3)5(NO2)]Cl2 and [Co(NH3)5(ONO)]Cl2, and investigate linkage isomerism. Linkage isomerism involves ligands that are capable of bonding through one type of atom in one situation and another type of atom in a different situation ...
6.Coordination Compounds
... •A molecule which has no plane of symmetry is described as chiral. The carbon atom with the four different groups attached which causes this lack of symmetry is described as a chiral centre or as an asymmetric carbon atom. The molecule with a plane of symmetry is described as achiral. Only chiral mo ...
... •A molecule which has no plane of symmetry is described as chiral. The carbon atom with the four different groups attached which causes this lack of symmetry is described as a chiral centre or as an asymmetric carbon atom. The molecule with a plane of symmetry is described as achiral. Only chiral mo ...
N,NH-Dialkyldithiocarbamate chelates of indium(III
... and carbon seems to suggest two different coordination modes of the ligand in solution; as known for dialkyldithiocarbamates [16] that can bond to the central metal atom in a conventional bidentate con®guration ...
... and carbon seems to suggest two different coordination modes of the ligand in solution; as known for dialkyldithiocarbamates [16] that can bond to the central metal atom in a conventional bidentate con®guration ...
Chapter 3 Ligand Effects
... Clearly, there is a need for techniques which provide access to enantiomerically pure compounds. There are a number of methods by which this goal can be achieved19. One can start from naturally occurring enantiomerically pure compounds (the chiral pool). Alternatively, racemic mixtures can be separa ...
... Clearly, there is a need for techniques which provide access to enantiomerically pure compounds. There are a number of methods by which this goal can be achieved19. One can start from naturally occurring enantiomerically pure compounds (the chiral pool). Alternatively, racemic mixtures can be separa ...
01-43 chimica.qxd
... Louis Hérrison and Yves Chauvin have been used in a variety of metathesis reactions to proposed that the catalyst was a induce asymmetry (6). compound in which the metal is Figure 1. Schrock bound to the carbon with a molybdenum catalysts double bond, often referred to as LATE TRANSITION METAL INITI ...
... Louis Hérrison and Yves Chauvin have been used in a variety of metathesis reactions to proposed that the catalyst was a induce asymmetry (6). compound in which the metal is Figure 1. Schrock bound to the carbon with a molybdenum catalysts double bond, often referred to as LATE TRANSITION METAL INITI ...
Hydrides: Solid State Transition Metal Complexes
... are reduced by constraints. For all these reasons, hydride structures are generally less well characterized than other solid-state structures. 2.4 Properties Most compounds are nonmetallic. Only few other properties are known. The main reason for this is the lack of single crystals, the presence of ...
... are reduced by constraints. For all these reasons, hydride structures are generally less well characterized than other solid-state structures. 2.4 Properties Most compounds are nonmetallic. Only few other properties are known. The main reason for this is the lack of single crystals, the presence of ...
PDF w - American Chemical Society
... 3a (Table 1). Of these strong XB donors iodine forms the strongest halogen bonds known while the F4DIBz and F8DIBu show noticeable shorter but still strong XB interaction with nucleophilic atoms (XB acceptors), such as N, O and S,3−8 but no previous halogen bonded complexes of the Pd-pincer or any o ...
... 3a (Table 1). Of these strong XB donors iodine forms the strongest halogen bonds known while the F4DIBz and F8DIBu show noticeable shorter but still strong XB interaction with nucleophilic atoms (XB acceptors), such as N, O and S,3−8 but no previous halogen bonded complexes of the Pd-pincer or any o ...
Accurate Spin-State Energies for Iron Complexes
... and experiment. On the experimental side, the situation may be complicated by ligand-exchange reactions,2 dimerization processes, oxidation/reduction, impurities, etc. Moreover, the structural characterization of the complexes may be hampered by problematic crystallization, reduced lifetimes of tran ...
... and experiment. On the experimental side, the situation may be complicated by ligand-exchange reactions,2 dimerization processes, oxidation/reduction, impurities, etc. Moreover, the structural characterization of the complexes may be hampered by problematic crystallization, reduced lifetimes of tran ...
Chemical Speciation of Sulfur and Metals in Biogas
... chemical speciation of the metals is regulated by hydrogen sulfide and the formation of metal sulfide precipitates, which in turn restrict the availability of metals for microorganisms. However, despite the limitations set by sulfide, aqueous concentrations of different Co and Ni species were shown ...
... chemical speciation of the metals is regulated by hydrogen sulfide and the formation of metal sulfide precipitates, which in turn restrict the availability of metals for microorganisms. However, despite the limitations set by sulfide, aqueous concentrations of different Co and Ni species were shown ...
Ir-catalysed formation of C− F bonds. From allylic alcohols to α
... Since SelectF in THF/water mixtures successfully produced only one constitutional isomer of the product (i.e. 2a 0 was not formed), further screening on this system was performed (Table 2). The best results were obtained using a THF/water mixture of 5 : 1. Less water failed to dissolve SelectF, and ...
... Since SelectF in THF/water mixtures successfully produced only one constitutional isomer of the product (i.e. 2a 0 was not formed), further screening on this system was performed (Table 2). The best results were obtained using a THF/water mixture of 5 : 1. Less water failed to dissolve SelectF, and ...
Growth of Platinum Clusters in Solution and on Biopolymers: The
... entirely, mainly, or at least to a significant extent, by bonds directly between the metal atoms, even though some nonmetal atoms may also be intimately associated with the cluster. This definition states that a group of atom can be classified as a cluster only in the presence of at least one direct ...
... entirely, mainly, or at least to a significant extent, by bonds directly between the metal atoms, even though some nonmetal atoms may also be intimately associated with the cluster. This definition states that a group of atom can be classified as a cluster only in the presence of at least one direct ...
Chapter 4: Structural features of rhenium carbene complexes
... The bond between the carbene carbon and the ring carbon atom C10–C11 is longer than C13–C14, which is believed to still have a lot of double bond character. A single carbon– carbon bond in complex 1 is that between the carbon atoms of the ethoxy substituent, and the length of this bond is 1.514 (8) ...
... The bond between the carbene carbon and the ring carbon atom C10–C11 is longer than C13–C14, which is believed to still have a lot of double bond character. A single carbon– carbon bond in complex 1 is that between the carbon atoms of the ethoxy substituent, and the length of this bond is 1.514 (8) ...
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.