Dataset Information

Solvent dependence of the monomer-dimer equilibrium of ketone-substituted triscatecholate titanium(IV) complexes.

ABSTRACT: Hierarchical helicates based on ketone-substituted titanium(IV)triscatecholates show different monomer-dimer behavior depending on different solvents. The dimerization constants of a whole series of differently alkyl-substituted complexes is analyzed to show that the solvent has a very strong influence on the dimerization. Hereby, effects like solvophobicity/philicity, sterics, electronics of the substituents and weak side chain-side chain interactions seem to act in concert.

SUBMITTER: Kwamen ACN

PROVIDER: S-EPMC7496165 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Solvent Dependence of the Monomer-Dimer Equilibrium of Ketone-Substituted Triscatecholate Titanium(IV) Complexes.

Kwamen A Carel N ACN Jenniches Judith J Oppel Iris M IM Albrecht Markus M

Chemistry (Weinheim an der Bergstrasse, Germany) 20200720 46

Hierarchical helicates based on ketone-substituted titanium(IV)triscatecholates show different monomer-dimer behavior depending on different solvents. The dimerization constants of a whole series of differently alkyl-substituted complexes is analyzed to show that the solvent has a very strong influence on the dimerization. Hereby, effects like solvophobicity/philicity, sterics, electronics of the substituents and weak side-chain-side-chain interactions seem to act in concert. ...[more]

PMID: 32222003

Similar Datasets

Project description:Although bovine beta-lactoglobulin assumes a monomeric native structure at pH 3 in the absence of salt, the addition of salts stabilizes the dimer. Thermodynamics of the monomer-dimer equilibrium dependent on the salt concentration were studied by sedimentation equilibrium. The addition of NaCl, KCl, or guanidine hydrochloride below 1 M stabilized the dimer in a similar manner. On the other hand, NaClO(4) was more effective than other salts by about 20-fold, suggesting that anion binding is responsible for the salt-induced dimer formation, as observed for acid-unfolded proteins. The addition of guanidine hydrochloride at 5 M dissociated the dimer into monomers because of the denaturation of protein structure. In the presence of either NaCl or NaClO(4), the dimerization constant decreased with an increase in temperature, indicating that the enthalpy change (DeltaH(D)) of dimer formation is negative. The heat effect of the dimer formation was directly measured with an isothermal titration calorimeter by titrating the monomeric beta-lactoglobulin at pH 3.0 with NaClO(4). The net heat effects after subtraction of the heat of salt dilution, corresponding to DeltaH(D), were negative, and were consistent with those obtained by the sedimentation equilibrium. From the dependence of dimerization constant on temperature measured by sedimentation equilibrium, we estimated the DeltaH(D) value at 20 degrees C and the heat capacity change (DeltaC(p)) of dimer formation. In both NaCl and NaClO(4), the obtained DeltaC(p) value was negative, indicating the dominant role of burial of the hydrophobic surfaces upon dimer formation. The observed DeltaC(p) values were consistent with the calculated value from the X-ray dimeric structure using a method of accessible surface area. These results indicated that monomer-dimer equilibrium of beta-lactoglobulin at pH 3 is determined by a subtle balance of hydrophobic and electrostatic effects, which are modulated by the addition of salts or by changes in temperature.

Dataset Information

Solvent dependence of the monomer-dimer equilibrium of ketone-substituted triscatecholate titanium(IV) complexes.

Publications

Solvent Dependence of the Monomer-Dimer Equilibrium of Ketone-Substituted Triscatecholate Titanium(IV) Complexes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets