L-histidin modifiye nanopartiküllerin kiral ligand ve Cu ’nin merkez iyon olarak kullanılması ile yeni bir kiral ligand değişim kapiler elektroforez yöntemi geliştirildi. İlk olarak, MAH ve EDMA’nın polimerizasyonu ile polimerik nanopartiküller hazırlandı. Nanopartiküller atomik kuvvet mikroskobu (AFM), FTIR ve elemental analiz ile karakterize edildi. Nanopartiküllerin elementel analizi sonucu ...

Chiral recognition mechanism and enantioseparation conditions of tryptophan enantiomers using ligand exchange chromatography are reported here. The effect of different kinds and concentration of ligands, bivalent copper ion, organic modifier, pH of mobile phase, and temperature on enantioseparation has been evaluated. The results show that the enantioselectivity is strongly affected by the pH a...

Mechanistic studies show the importance of iodide displacement by additives that accelerate reactions of samarium diiodide. The key feature important for acceleration of reaction rate is the use of proton donors and other additives that have a high enough affinity for Sm(II) to displace iodide yet do not saturate the coordination sphere inhibiting substrate reduction.

In the quest for single molecule magnets (SMMs), several new homo- and heterometallic (Co, Mn, Ni, Zn) paramagnetic coordination compounds have been synthesized, based on a rigid diimine-pyridine pincer ligand. X-ray crystallography reveals their structure, while magnetic studies reveal ferromagnetic exchange interactions in some of them.

To explore the displacement of Zn(2+) by Ni(2+) from within N-, S-, and O-chelate ligands, (N-(3-thiabutyl)-N'-(3-thiapentaneoate)-1,4-diazacycloheptane)zinc(II), Zn-1'-Ac, and 1,4-diazacycloheptane-1,4-diylbis(3-thiapentanoato) zinc(II), Zn-1'-Ac(2), were reacted with Ni(BF(4))(2) in a methanol solution and were found to yield, in both cases, the bright blue, hexa-coordinate Ni-1'-Ac(2) metal-...

Synthetic chemists have provided a wide array of supramolecular assemblies able to encapsulate guest molecules. The scope of this tutorial review focuses on supramolecular host molecules capable of reversibly encapsulating polyatomic guests. Much work has been done to determine the mechanism of guest encapsulation and guest release. This review covers common methods of monitoring and characteri...

We have studied the structural elements that affect ligand exchange between the two high affinity biotin-binding proteins, egg white avidin and its bacterial analogue, streptavidin. For this purpose, we have developed a simple assay based on the antipodal behavior of the two proteins toward hydrolysis of biotinyl p-nitrophenyl ester (BNP). The assay provided the experimental basis for these stu...

Introduction: Recently, the classic theory of stable isotope fractionation of the Bigeleisen-Mayer equation [1] has been expanded by the original author to include the mass-independent term named the nuclear field shift effect [2]. The improved theory successfully explained the observed non-linear isotope effect on U in a chemical exchange system [2]. Since then, researchers have applied the ne...

The mechanism of intermolecular ligand exchange has been studied using transition path sampling (TPS) based molecular dynamics (MD) simulations. Specifically, the exchange of solvent molecules bound to unsaturated Cr(CO)5 in methanol solution has been investigated. The results of the TPS simulations have shown that there are multiple steps in the reaction mechanism. The first involves partial d...

Site-specific mutants of human myoglobin have been prepared in which lysine 45 is replaced by arginine (K45R) and aspartate 60 by glutamate (D60E), in order to examine the influence of these residues and their interaction on the dynamics of the protein. These proteins were studied by a variety of methods, including one and two-dimensional proton nuclear magnetic resonance spectroscopy, exchange...