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Ligand substitutions

As mentioned earlier, the substitution of one ligand for another in a complex is the most common type of reaction that complexes undergo. If the starting complex contains n ligands of type L and one ligand X that is replaced by Y, this type of reaction can be shown in a general form by the equation [Pg.485]

Although the subject of reaction mechanism will be considered later, it is appropriate at this time to mention that there are two possible limiting mechanisms for this type of reaction. In the first, the ligand X leaves slowly before Y enters so that the reaction can be represented by the following scheme  [Pg.485]

Such a mechanism is known as a dissociative mechanism because dissociation of the M-X bond is the slow (rate-determining) step in the process. Such a mechanism can also be considered as a first-order or SN1 mechanism. [Pg.485]

If the reaction takes place with Y entering before X leaves, it can be represented by the following scheme  [Pg.485]

In this case, formation of the transition state requires both L M-X and Y, and the rate of the reaction depends on the concentration of both species. Therefore, the rate law can be written as [Pg.486]

Sometimes the first (and last) step in a catalytic cycle (to be discussed in Chapter 9), for example, ligand substitution is a common reaction type. This reaction is comparable in many ways to substitutions that occur at the carbon atom in organic chemistry. Equation 7.1 shows the general reaction. [Pg.178]

Much of the work on ligand substitution of organometallic complexes has involved metal carbonyls with a trialkyl or a triarylphosphine serving as the replacement ligand. Two main mechanistic pathways exist by which substitution may occur— associative (A) and dissociative (D). [Pg.178]

2For a good discussion of a number of common types of organometallic reactions, see C. A. Tolman, Chem. Soc. Rev., 1972,1, 337. [Pg.178]

The spectrum of pathways from D through I to A is analogous to the SN1-SN2 manifold found in organic chemistry.3 [Pg.179]

Ligands that form strong a bonds, such as hydride and alkyl, or n acceptor ligands, such as CN, CO, and PR3, which also bond strongly to the metal, tend [Pg.179]

2 Formatiou of Metal-Carbou r-Bouds by Oxidative Additiou [Pg.260]

A very common method for forming metal carbon a-bonds is by an oxidative addition reaction this usually involves the addition of R-X (R = alkyl, aryl, etc, X = halide, etc) to a metal complex in a low oxidation state. In such a reaction, the oxidation state increases by 2 the coordination number of the metal also increases, usually also by 2. A good example is the addition of Me-I to [Rh(CO)2l2] (4-coordinate square planar, Rh(I), cf, NVE, 16, Box 1) to give [Rh(Me)(CO)2l3] (6-coordinate Rh(III), cf, NVE, 18) in the rate determining step of the Monsanto cycle for making acetic acid (Equation 4 and Chapter 4, Section 4.2.5), [Pg.260]

Many examples of ctjcf oxidative addition reactions similar to the above are known 5-coordinate species undergo the reaction but often with loss of a ligand, for example, Fe(0) c to Fe(II) f, (Equation 5) [Pg.260]

Other common oxidative additions involve the transformation of metal centres to ct (Equation 6), [Pg.261]

In this case the formation of two Fe-C a-bonds has increased the formal oxidation state of the metal from Fe(0), d, to Fe(II), cf. [Pg.261]


The ligand substitution reaction of CH2CI2 in Cp(NO)(Ph3P)Re(ClCH2Cl) " by thiophene and 2,5-dimethylthiophene yields the (S) coordinated complex of type... [Pg.18]

Complex 105 enters the pyrazoleAriphenylphosphine ligand substitution reaction with PPha to give 108 (910M3123). Further reaction with triphenylphosphine and silver tetrafluoroborate gives the heterodinuclear complex 109 (94IC2196). [Pg.182]

Oxidative addition of XY substrates to [IrL2(/x-pz)]2 [La = (CO)2, cod] and [Ir(CD)(PPh3)(/i,-pz)]2 occurs via a two-center, two-electron route toward the iridium-iridium bond-containing species 131 (960M3785 980M2743). Complex 132, which is prepared by the ligand-substitution reaction from [Ir(CO)2 (/x-pz)]2, adds methyl iodide to give 133. [Pg.190]

The electrochemical behavior of niobium in different types of molten electrolytes and the influence of ligand substitution in niobium-containing complex ions on the reduction mechanism is comprehensively reviewed by Polyakov [555]. [Pg.323]

Square planar complexes of palladium(II) and platinum(II) readily undergo ligand substitution reactions. Those of palladium have been studied less but appear to behave similarly to platinum complexes, though around five orders of magnitude faster (ascribable to the relative weakness of the bonds to palladium). [Pg.237]

The cis- and trans-isomers of [Pt(NH3)(N02)Cl2]- have been synthesized from PtCl - merely by choice of the order of ligand substitution (Figure 3.87). (In the second step, chloride trans to chloride is more labile.) The second substitution is dictated by N02 having a higher position in the trans-effect series than chloride [144],... [Pg.240]

Ligand substitution reactions at low-valent four-, five- and six-coordinate transition metal centres. J. A. S. Howell and P. M, Burkinshaw, Chem. Rev., 1983, 83, 557-599 (468). [Pg.62]

The definition is also useful when the order changes with concentration, as different values of the concentrations are used. The following ligand substitution reaction5 is an example, because the order with respect to [H+] depends upon [H+] ... [Pg.6]


See other pages where Ligand substitutions is mentioned: [Pg.256]    [Pg.546]    [Pg.343]    [Pg.12]    [Pg.184]    [Pg.62]    [Pg.170]    [Pg.171]    [Pg.1027]    [Pg.1030]    [Pg.1188]    [Pg.51]    [Pg.28]    [Pg.36]    [Pg.141]    [Pg.151]    [Pg.177]    [Pg.163]    [Pg.166]    [Pg.188]    [Pg.197]    [Pg.213]    [Pg.216]    [Pg.152]    [Pg.153]    [Pg.25]    [Pg.171]    [Pg.171]    [Pg.175]    [Pg.190]    [Pg.195]    [Pg.197]    [Pg.208]    [Pg.215]    [Pg.226]    [Pg.199]    [Pg.202]    [Pg.35]    [Pg.68]    [Pg.115]    [Pg.167]    [Pg.130]    [Pg.235]   
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18-electron complexes ligand substitution

18-electron complexes ligand substitution mechanism

Acetylene complexes ligand substitution

Alkyl-Substituted Ligands

Arene ligand reactivity nucleophilic substitution

Aryl-Substituted Ligands

Assisted Ligand Substitution Reactions

Associative Ligand Substitution Reactions and the Berry Rearrangement

Associative Substitution by Pentadienyl Ligand Ring Slip

Associative ligand exchange square-planar substitution reactions

Associative ligand substitution

Associative ligand substitution Kinetics

Associative ligand substitution Mechanism

Associative ligand substitution Stereochemistry

Associative ligand substitution reactions

Associative ligand substitution trans Effect

Asymmetric ligands allylic derivatives, substitution reactions, chiral

Axial ligand substitution reactions

Axial ligands, substitution properties

Blood substitutes ligand binding

Bond dissociation energies ligand substitution process

Bridging ligands substitution

CARBONYLS, PHOSPHINE COMPLEXES, AND LIGAND SUBSTITUTION REACTIONS

Carbonyl ligands substitution reactions

Carboxamido substituted heterocyclic ligands

Catalysts/catalysis ligand substitution

Catalysts/catalysis ligand substitution reactions

Catalytic processes ligand substitution

Catalyzed ligand substitution reactions

Cationic metal carbonyls ligand substitution reactions

Chemical reactivity ligand substitution

Chiral ligands allylic derivatives, substitution reactions

Chromium complexes ligand substitution reactions

Chromium ligand substitution reactions

Cobalamins ligand substitution reactions

Cobalt complexes ligand substitution

Cobalt complexes, ligand substitution reactions

Cobalt ligand substitution reactions

Conformations, ligand ring substitution

Coordination chemistry ligand substitution reactions

Coordination compounds ligand substitution

Copper ligand substitution

Dissociative ligand substitution

Dissociative ligand substitution reactions

Dissociative ligand substitution reactions aqua ions

Electrocatalysis ligand substitution

First order kinetics ligand substitution reactions

Formation Involving Unsubstituted Metal Ions Multidentate Ligand Substitution

Further Ligands Used in Ir-Catalyzed Allylic Substitutions

Germanium compounds ligand substitution

Gold compounds ligand substitution

Group 5 metal halide clusters ligand substitution

Grubbs ligand substitution

Halides ligand substitution

Heteroatom-substituted secondary phosphine oxide ligands

Hydride complexes ligand substitutions

INDEX ligand substitution

Induced ligand substitution

Interchange ligand substitution reactions

Intimate mechanisms of ligand substitution

Iridium ligand substitution reactions

Iron complex ligand substitution

Iron complexes ligand substitution reactions

Iron compounds ligand substitution

Iron-sulfur clusters ligand substitution

Kinetics ligand substitution

Labile transition-metal ions, ligand substitution

Lanthanides ligand substitutions

Ligand Dissociation and Substitution

Ligand Exchange and Substitution

Ligand Substitution Reactions in Aqueous Solution

Ligand Substitution Reactions in Carbonyl Metal Clusters

Ligand Substitution in Transition Metal ir-Complexes

Ligand Substitution in Transition Metal w-Complexes

Ligand Substitution on Labile Transition-Metal Ions

Ligand exchange/substitution

Ligand exchange/substitution associative

Ligand exchange/substitution dissociative

Ligand exchange/substitution interchange

Ligand interactions substitution

Ligand substitution by ion exchange in non-aqueous solvents

Ligand substitution in octahedral complexes

Ligand substitution in square planar complexes

Ligand substitution labile terminal ligands

Ligand substitution linker ligands

Ligand substitution mechanisms

Ligand substitution mechanisms complexes

Ligand substitution mechanisms factors controlling

Ligand substitution mechanisms square-planar, 16-electron

Ligand substitution organometallic systems

Ligand substitution rate constant

Ligand substitution reactions

Ligand substitution reactions aluminum

Ligand substitution reactions associative mechanism

Ligand substitution reactions bismuth

Ligand substitution reactions cadmium

Ligand substitution reactions compounds

Ligand substitution reactions coordinated ligands

Ligand substitution reactions copper

Ligand substitution reactions dissociative mechanism

Ligand substitution reactions exchange

Ligand substitution reactions gallium

Ligand substitution reactions gold

Ligand substitution reactions high oxidation state complexes

Ligand substitution reactions indium

Ligand substitution reactions inert octahedral complexes

Ligand substitution reactions interchange mechanism

Ligand substitution reactions iron

Ligand substitution reactions lanthanides

Ligand substitution reactions mercury

Ligand substitution reactions model mechanisms

Ligand substitution reactions nickel

Ligand substitution reactions nonsymmetrical

Ligand substitution reactions nucleophilic attack

Ligand substitution reactions osmium

Ligand substitution reactions photochemical

Ligand substitution reactions platinum

Ligand substitution reactions rhodium

Ligand substitution reactions rhodium complexes

Ligand substitution reactions ruthenium

Ligand substitution reactions ruthenium complexes

Ligand substitution reactions square-planar complexes

Ligand substitution reactions supramolecular chemistry

Ligand substitution reactions transition metal complexes

Ligand substitution reactions zinc

Ligand substitution reactions, classification

Ligand substitution reactivity

Ligand substitution solvent exchange reactions

Ligand substitution stereochemistry

Ligand substitution, kinetic control

Ligand substitution, metals/metal complexes

Ligand substitution, photo

Ligand substitutions abstractions

Ligand substitutions defined

Ligand substitutions overview

Ligand substitutions some general points

Ligand sugar-substituted

Ligand synthesis nucleophilic substitution

Ligand-assisted substitution

Ligands nonbridging, substitution

Ligands perfluoroalkyl-substituted

Ligands substituted cyclopentadienyl

Ligands substitution, nitric oxide

Ligands substitutive-type nomenclature

Ligands with fluorine-substituted aryl groups

Mechanisms of ligand substitution reactions

Mechanisms of ligand substitution reactions general considerations

Mechanisms of ligand substitution reactions postscript

Metal carbonyls ligand substitution reactions

Metal complexes ligand substitution mechanisms

Metal ions ligand substitution

Metal-carbene complexes ligand substitution reactions

Mixed-ligand complexes substitution

Mixed-metal clusters ligand substitution

Molybdenum complexes ligand substitution

Multidentate ligand, substitution

Multidentate ligand, substitution reactions

Multidentate ligands, lead substitution

Multidentate ligands, lead substitution reactions

New Chiral Ligands Based on Substituted Heterometallocenes

Nickel complexes ligand substitution reactions

Nucleophilic substitution ligand attacks

Nucleophilic substitutions ligands

Olefin complexes dissociative ligand substitutions

Organosilyl-substituted w-ligands migration of silyl groups

Other Assisted Ligand Substitutions

Other Ligand Substitutions

Overview of Ligand Substitution

Oxide ligand substitution

Palladium associative ligand substitutions

Palladium asymmetric allylic substitutions, phosphine ligands

Palladium complexes ligand substitutions

Palladium ligand substitutions

Phosphine ligands nucleophilic substitution

Phosphoramidite ligands substitution

Phosphorus ligands, alkyl substituted

Photochemical ligand substitution

Photochemical ligand substitution changes

Photochemical ligand substitution isomerization

Photochemical ligand substitution mechanisms

Photochemical ligand substitution photophysical properties

Photochemical ligand substitution spectra

Pseudo-first order kinetics, ligand substitution

Pseudo-first order kinetics, ligand substitution reactions

Quadruple bonds ligand substitution

Second order kinetics ligand substitution reactions

Selenium ligands substitution reactions

Solution methods ligand substitution reactions

Sonochemical ligand substitution

Sonochemical ligand substitution temperatures

Square-planar substitution reactions ligand exchange

Square-planar substitution reactions nucleophilic ligand

Statistical Ligand Substitution

Stereospecific ligand substitution

Substituted Carbonyls Containing Four-Electron Group IVB Ligands

Substituted Carbonyls Containing Six-Electron Group IVB Ligands

Substituted Carbonyls Containing Three-Electron Group IVB Ligands

Substituted Carbonyls Containing Two-Electron Group IVB Ligands

Substituted pyrrolyl ligands

Substitution Reactions of Noncarbene Ligands

Substitution and Exchange Reactions of CO Ligands

Substitution in Carbonyls Replacement of other Ligands

Substitution ligand rearrangement

Substitution of CO ligands

Substitution of Coordinated Ligands with Olefins

Substitution of Ligands at the Transition Metal

Substitution of Unidentate Ligands

Substitution of Weakly Bound Ligands in 18-Electron Complexes

Substitution of carbonyl ligands

Substitution of ligand

Substitution reactions ligand field effect

Substitution reactions without metal-ligand bond cleavage

Substitutions of Other Ligands

Thallium complexes ligand substitutions

Transition metal ions ligand substitution

Transition metal ions ligand substitution reactions

Triruthenium complexes, axial ligand substitution

Trispyrazolylborate substituted ligands

Vinylidene ligand substitution

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