Early stages of the hydrolysis of chromium(III) in aqueous solution—XII. Kinetics of cleavage of the trimer and tetramer in acidic solution

The use of chromium(III) complexes to enhance peptide protonation by electrospray ionization mass spectrometry

“…Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement . The residence time of a water molecule in the first hydration shell of Cr(III) is 23 days.…”

“…aqueous solution. [11][12][13] Chromium(III) is a hard Lewis acid that preferentially binds to oxygen rather than nitrogen. 14 In addition, Cr(III) has the ability to bind to carboxylic acid groups in peptides.…”

“…The Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement. [11][12][13] The residence time of a water molecule in the first hydration shell 74 77 Therefore, the Z-spray ionization process may destabilize the peptide-Cr(III)-water complex before an "extra" proton is transferred to peptide ions. The absence of enhanced protonation in the Z-spray source further supports our hypothesis that this is a gas-phase or desolvation-phase effect, as opposed to a solution-phase effect occurring before the ESI event.…”

The use of chromium(III) complexes to enhance peptide protonation by electrospray ionization mass spectrometry

“…Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement . The residence time of a water molecule in the first hydration shell of Cr(III) is 23 days.…”

“…aqueous solution. [11][12][13] Chromium(III) is a hard Lewis acid that preferentially binds to oxygen rather than nitrogen. 14 In addition, Cr(III) has the ability to bind to carboxylic acid groups in peptides.…”

“…The Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement. [11][12][13] The residence time of a water molecule in the first hydration shell 74 77 Therefore, the Z-spray ionization process may destabilize the peptide-Cr(III)-water complex before an "extra" proton is transferred to peptide ions. The absence of enhanced protonation in the Z-spray source further supports our hypothesis that this is a gas-phase or desolvation-phase effect, as opposed to a solution-phase effect occurring before the ESI event.…”

Minerals as Molecules—Use of Aqueous Oxide and Hydroxide Clusters to Understand Geochemical Reactions

“…[48][49][50][51] These bridge-formation reactions generally involve the nucleophilic substitution of a water ligand coordinated to one metal center by a hydroxide ligand attached to a second metal center. Hydroxides are important, because the coordinated water ligands are generally poor nucleophiles and unlikely to be involved.…”

“…[52] The analysis of the kinetic data took into account the possibility of multiple reaction pathways, all of which involve deprotonated forms of the reacting aqua ion and/or oligomers. [48][49][50][51] Individual bridge-formation reactions leading to each oligomer, and their respective rates of formation, have been summarized in the Supplemental Information. In these reactions, the rate-determining step is difficult to ascertain, since some intermediates may be present in undetectably low concentrations and may undergo rapid intramolecular condensation.…”

The use of chromium(III) complexes to enhance peptide protonation by electrospray ionization mass spectrometry

“…Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement . The residence time of a water molecule in the first hydration shell of Cr(III) is 23 days.…”

“…aqueous solution. [11][12][13] Chromium(III) is a hard Lewis acid that preferentially binds to oxygen rather than nitrogen. 14 In addition, Cr(III) has the ability to bind to carboxylic acid groups in peptides.…”

“…The Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement. [11][12][13] The residence time of a water molecule in the first hydration shell 74 77 Therefore, the Z-spray ionization process may destabilize the peptide-Cr(III)-water complex before an "extra" proton is transferred to peptide ions. The absence of enhanced protonation in the Z-spray source further supports our hypothesis that this is a gas-phase or desolvation-phase effect, as opposed to a solution-phase effect occurring before the ESI event.…”

Minerals as Molecules—Use of Aqueous Oxide and Hydroxide Clusters to Understand Geochemical Reactions

“…[48][49][50][51] These bridge-formation reactions generally involve the nucleophilic substitution of a water ligand coordinated to one metal center by a hydroxide ligand attached to a second metal center. Hydroxides are important, because the coordinated water ligands are generally poor nucleophiles and unlikely to be involved.…”

“…[52] The analysis of the kinetic data took into account the possibility of multiple reaction pathways, all of which involve deprotonated forms of the reacting aqua ion and/or oligomers. [48][49][50][51] Individual bridge-formation reactions leading to each oligomer, and their respective rates of formation, have been summarized in the Supplemental Information. In these reactions, the rate-determining step is difficult to ascertain, since some intermediates may be present in undetectably low concentrations and may undergo rapid intramolecular condensation.…”

The use of chromium(III) complexes to enhance peptide protonation by electrospray ionization mass spectrometry

“…Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement . The residence time of a water molecule in the first hydration shell of Cr(III) is 23 days.…”

“…aqueous solution. [11][12][13] Chromium(III) is a hard Lewis acid that preferentially binds to oxygen rather than nitrogen. 14 In addition, Cr(III) has the ability to bind to carboxylic acid groups in peptides.…”

“…The Water ligands have an unusually long lifetime around Cr(III) due to a kinetic inertness to displacement. [11][12][13] The residence time of a water molecule in the first hydration shell 74 77 Therefore, the Z-spray ionization process may destabilize the peptide-Cr(III)-water complex before an "extra" proton is transferred to peptide ions. The absence of enhanced protonation in the Z-spray source further supports our hypothesis that this is a gas-phase or desolvation-phase effect, as opposed to a solution-phase effect occurring before the ESI event.…”

Minerals as Molecules—Use of Aqueous Oxide and Hydroxide Clusters to Understand Geochemical Reactions

“…[48][49][50][51] These bridge-formation reactions generally involve the nucleophilic substitution of a water ligand coordinated to one metal center by a hydroxide ligand attached to a second metal center. Hydroxides are important, because the coordinated water ligands are generally poor nucleophiles and unlikely to be involved.…”

“…[52] The analysis of the kinetic data took into account the possibility of multiple reaction pathways, all of which involve deprotonated forms of the reacting aqua ion and/or oligomers. [48][49][50][51] Individual bridge-formation reactions leading to each oligomer, and their respective rates of formation, have been summarized in the Supplemental Information. In these reactions, the rate-determining step is difficult to ascertain, since some intermediates may be present in undetectably low concentrations and may undergo rapid intramolecular condensation.…”