Tadao Hakushi

Bio: Tadao Hakushi is an academic researcher from Osaka University. The author has contributed to research in topics: Crown ether & Photoisomerization. The author has an hindex of 23, co-authored 106 publications receiving 2043 citations. Previous affiliations of Tadao Hakushi include National Presto Industries.

Thermodynamics of molecular recognition by cyclodextrins. 1. Calorimetric titration of inclusion complexation of naphthalenesulfonates with .alpha.-, .beta.-, and .gamma.-cyclodextrins: enthalpy-entropy compensation

Abstract: Calorimetric titrations have been performed at 25 o C in buffered aqueous solution (pH 7.20) to give the complex stability constants and the thermodynamic parameters for the inclusion complexation of naphthalenesulfonates 1-6 and naphthaleneacetate 7 with α-, β-, and γ-cyclodextrins (CDs). Data analyses assuming 1:1 stoichiometry were successfully applied to all of the host-guest combinations employed, except for the inclusion of 2-naphthalenesulfonate 2 with γ-CD, where both 1:1 and 1:2 host-guest complex formations were observed

Molecular design of crown ethers. 1. Effects of methylene chain length: 15- to 17-crown-5 and 18- to 22-crown-6

Abstract: Synthese des ethers crown et evaluation de leur aptitude a former des cations par extraction par solvant des picrates alcalins aqueux. La stabilite des complexes cation-ether crown est gouvernee par la variation d'enthalpie

Convenient and efficient tosylation of oligoethylene glycols and the related alcohols in tetrahydrofuran-water in the presence of sodium hydroxide

Abstract: Oligoethylene glycols and some related alcohols were efficiently tosylated with p-toluenesulfonyl chloride in a tetrahydrofuran–water (1:1) mixture in the presence of excess sodium hydroxide. This method is advantageous over the conventional tosylation in pyridine both regarding the work-up procedure, the yield, and the purity of the product, and may be potentially useful for the tosylation of certain acid-labile alcohols.

Enthalpy–entropy compensation in complexation of cations with crown ethers and related ligands

Abstract: Thermodynamic parameters indicate that the enthalpy–entropy compensation effect holds in general for complexation of cations with glymes/podands, crown ethers, cryptands, and macrocyclic antibiotics in various solvents. Thus the ΔH–TΔS plots give fairly good linear relationships for each type of ligand, with different slopes (α) and intercepts (TΔS0) characteristic of the type. The nature of the cation–ligand interaction is discussed in terms of α and TΔS0 values.

Molecular design of crown ethers. 4. Syntheses and selective cation binding of 16-crown-5 and 19-crown-6 lariats

Abstract: Les pouvoirs d'extraction des ethers lariat 16-crown-5 pour les cations mono- et divalents augmentent avec la longueur du bras oxyethylene lateral

Anion Recognition and Sensing: The State of the Art and Future Perspectives

Abstract: Anion recognition chemistry has grown from its beginnings in the late 1960s with positively charged ammonium cryptand receptors for halide binding to, at the end of the millennium, a plethora of charged and neutral, cyclic and acyclic, inorganic and organic supramolecular host systems for the selective complexation, detection, and separation of anionic guest species. Solvation effects and pH values have been shown to play crucial roles in the overall anion recognition process. More recent developments include exciting advances in anion-templated syntheses and directed self-assembly, ion-pair recognition, and the function of anions in supramolecular catalysis.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Abstract: Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.