We investigated the complexation of valinomycin (VM) in different solvent environments with the aid of the UVRR spectroscopy. By probing the 206.5 and 229 nm excited Raman spectra, we showed that new bands are observed around 1700 and 1290 cm(-1). We assigned the 1700 cm(-1) band to the hydrogen bonded ester carbonyl stretching vibration. In a polar solvent, VM-K(+) complexation shows significa...

Cucurbit[8]uril (CB[8])-mediated complexation of a dicationic azobenzene in water allows for the light-controlled encapsulation of a variety of second guest compounds, including amino acids, dyes, and fragrance molecules. Such controlled guest sequestration inside the cavity of CB[8] enables the regulation of the thermally induced phase transition of poly(N-isopropylacrylamide)-which is not pho...

Complexation of chlorogenic acid (CA) by b-cyclodextrin (b-CD) at mildly acidic pH, was studied by fluorescence spectroscopy, isothermal titration calorimetry (ITC), cyclic voltammetry (CV) and NMR spectroscopy. Thermodynamic parameters (DH°, DS° and K) determined by both fluorescence and ITC, showed that the complexation of CA by b-CD is an enthalpy-driven process. Results show that CA molecul...

Crown ether complexation solubilizes organic and inorganic salts in nonpolar media. Induction of crystallization from such solutions can result in crystallization of the free salt rather than the complex. This affords the opportunity to examine solvent effects on the crystallization of salts and other polar materials, leading to the modification of crystal shape and lattice. This approach, whic...

The complexation of Cm(III) with the recombinant N-lobe of human serum transferrin (hTf/2N) is investigated in the pH range from 4.0 to 11.0 using TRLFS. At pH ≥ 7.4 a Cm(III) hTf/2N species is formed with Cm(III) bound at the Fe(III) binding site. The results are compared with Cm(III) transferrin interaction at the C-lobe and indicate the similarity of the coordination environment of the C- an...

We report the noncovalent linkage of terminally substituted oligo(dimethylsiloxanes) bearing α-cyclodextrins (α-CD) as host end groups for the cyclopentadienyl rings of ferrocene. This double complexation of unsubstituted ferrocene leads to a supramolecuar formation of the siloxane strands. Structural characterization was performed by the use of (1)H NMR and IR spectroscopy and by mass spectrom...

We have designed and synthesized a new ligand, 6-(2-pyridinyl)-4-[3'-(3-pyridinyl)[1,1'-biphenyl]-3-yl]-2,2'-bipyridine (2). 2 reacted with Pt(cod)(MeCN)(2)(BF(4))(2) to quantitatively give the molecular dimer, 1.BF(4) (2(2).Pt(II)(2).4BF(4)(-)), by self-assembly. The (1)H NMR and UV-vis titration showed that the complexation affinity of 1.BF(4) toward benzenediol guests decreases in the order ...

The synthesis of a new linear bis-tetraamine ligand L1, based on two 1,4,8,11-tetraazaundecane units grafted at the 2 and 6 positions of a pyridinyl linker substituted by an anthracenyl fluorophore in the para position, is described and anion complexation studies of L1 with anionic substrates are reported. The protonation pattern and the study of the binding properties of L1 in an aqueous mediu...

Receptor-mediated endocytosis can be exploited for improving the transcellular delivery of therapeutic proteins. Insulin conjugated to transferrin by forming disulfide bonds has been shown to improve insulin oral bioavailability in diabetic rats. We are developing a combination strategy involving complexation hydrogels as delivery vehicles for insulin-transferrin conjugates. The complexation hy...

The sorption of copper ions onto natural bamboo sawdust with cellulose-lignin polymeric structure strongly depends on pH. The adsorption capacity for copper ions increases as increasing pH and copper loadings. The fitting of copper pH boundary curve by NEM surface complexation models shows that: three-sites model including the ion exchange reaction of permanent charge fits better than two-sites...