Ligands, hydrophobicity

Complex aminoacid sequences structure Thiophilic like ligands Hydrophobic charge transfer effect... 

Zhong, D., Douhal, A., and Zewail, A.H. (2000) Femtosecond studies of protein-ligand hydrophobic binding and dynamics human serum albumin Proc. Natl. Acad. Sci. 97, 14056-14061. 

A series of 4-alkylamido-2-hydroxybenzoic acids containing a different number of carbon atoms in the alkyl-amido group has been studied as model ligands for metal ion extraction in aqueous micellar solutions of nonionic surfactants. Their acid-base properties and reactivity towards metal ions in the presence of micelles were investigated. By operating at a proper temperature, the separation of the iron (III) chelate complexes into a micellar rich phase was achieved and the extraction efficiency was correlated with the ligand hydrophobicity. 

The results obtained with the reported extraction model showed that the separation of charged species is possible, provided a suitable ligand hydrophobicity. Further analytical developments of these multiphase extraction systems will require an accurate investigation of the equilibria and kinetic processes occurring at the interfaces, as well as the study of the micellar structure and properties of the host aggregates. 

Comparison of calculated desolvation free energies with IQ, values suggested the importance of ligand hydrophobicity (low desolvation free energy) for effective cation-ir interaction of the homodimer (245) with peripheral site(s). 

The summary conclusion drawn was that overall ligand hydrophobicity is important for BZR binding and that for the classical benzo-diazepinone chemotype the hydrophobicl steric effects of moieties appended to positions C7 and C2 are positively associated with receptor affinity. 

In addition to a proper choice of ligand hydrophobicity, the surfactant used is also critical. In general, non-ionic surfactants were found to be efficient for colloidal stabilization of the polymer particles [221]. This is to be expected, as, owing to the ionic nature of the catalyst, and the corresponding ionic strength, electrostatic stabilization is likely to be poor. Adequate hydrophilic/lipophilic balance (HLB) [222] is also a necessary criterion to ensure latex stability in ATR emulsion polymerization [223]. 

MMA MbiB dNbPy D PMMA Brij 78 Methyl methacrylate 2-Bromo-2-methylpropionic acid methyl ester 4,4 -Dinonyl-2,2 -bipyridine Decane Poly(methyl methacrylate) (7H, Rohm) Poly(oxyethylene stearyl ether) Monomer Initiator Ligand Hydrophob/GC-Standard Co-hydrophob Emulsifier ... 

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