History of Solution Chemistry of Japan

A historical view of the solution chemistry of Japan is described for a wide range of fields of solution chemistry, which relates to physical chemistry, inorganic chemistry, analytical chemistry, biochemistry and bioinorganic chemistry, and colloid and polymer chemistry. The works by pioneers of Japanese solution chemistry are introduced, some of which are not well recognized internationally. The influences of Japanese solution chemistry on the world and vice versa are discussed on the basis of a rather personal viewpoint. Recent activities of Japanese solution chemists at the national and international levels are also reviewed.     

Hafnium(IV)-nitrilotriacetate and hafnium(IV)-fluoride complexes investigated using an ion-selective electrode

Models of plutonium solution chemistry in vivo require formation constants which are difficult to obtain but hafnium(IV) is biochemically similar t     

Processes that affect electrospray ionization-mass spectrometry of nucleobases and nucleosides

Due to the complexity of electrospray ionization processes and the many factors that affect the ion signal, optimization of electrospray ionization methods to gain ultimate sensitivity for analysis of nucleobases and nucleosides may not be straightforward. In this work, we investigated the effect of the pK _a and the gas-phase basicity of analyte and other electrolytes on the [M+H]⁺ ion signal for 11 select nucleobases and nucleosides in 50% methanol:water solution. Solution chemistry plays a role in the electrospray signal for all analytes, but gas-phase chemistry may be important for compounds with pK _a <3 depending on the solution composition. For compounds with pK _a <3, gas-phase proton transfer reactions can be promoted to increase analyte electrospray response by the addition of ammonium acetate to the solution.     

Fragmentation of chloroperoxides: hypochlorite-mediated dehydration of hydroperoxyacetals to esters

Hypochlorites efficiently dehydrate hydroperoxyacetals to furnish the corresponding esters. The reaction, which can be accomplished with stoichometric Ca(OCl)₂ or with catalytic amounts of t-BuOCl, appears to involve formation and heterolytic fragmentation of secondary chloroperoxides, species not previously described in solution chemistry.     

HOA (Heaviside Operational Ansatz) revisited: recent remarks on novel exact solution methodologies in wavefunction analysis

A viable methodology for the exact analytical solution of the multiparticle Schrodinger and Dirac equations has long been considered a holy grail of theoretical chemistry. Since a benchmark work by Torres-Vega and Frederick in the 1990s, the QPSR (Quantum Phase Space Representation) has been explored as an alternate method for solving various physical systems. Recently, the present author has developed an exact analytical symbolic solution scheme for broad classes of differential equations utilizing the HOA (Heaviside Operational Ansatz). An application of the scheme to chemical systems was initially presented in Journal of Mathematical Chemistry (Toward chemical applications of Heaviside Operational Ansatz: exact solution of radial Schrodinger equation for nonrelativistic N-particle system with pairwise 1/r(I) radial potential in quantum phase space. Journal of Mathematical Chemistry, 2009; 45(1):129–140). It is believed that the coupling of HOA with QPSR represents not only a fundamental breakthrough in theoretical physical chemistry, but it is promising as a basis for exact solution algorithms that would have tremendous impact on the capabilities of computational chemistry/physics. The novel methods allow the exact determination of the momentum [and configuration] space wavefunction from the QPSR wavefunction by way of a Fourier transform. In this note some remarks, examples and further directions, concerning HOA as a tool to solve and provide analytical insight into solutions of dynamical systems occurring in, but not limited to Mathematical Chemistry, are also posited.     

Water-soluble supramolecular polymers constructed by macrocycle-based host-guest interactions

Water soluble supramolecular polymers are especially important due to their superior biocompatibility and environmental adaptation, which determined they have wide applications in various areas, such as drug delivery, self-healing, shape memory. On the other hand, macrocyclic compounds are the most used building blocks in the preparation of supramolecular polymers. Macrocycle-based supramolecular polymers, which introduce the host-guest interaction in the system, endow these polymers with interesting and smart physicalchemical properties. In this review, we summarized recent studies about supramolecular polymers in aqueous solution based on macrocyclic compounds.     

Some developments in the phosphitetriester method for synthesis of oligonucleotides

1,l-Dimethyl-2,2,2-trichloroethyl has merit as a protecting group for P-O in the phosphite-triester synthesis of oligonucleotides. Use of this group enables one to simplify procedures for preparing active nucleoside phosphorochloridite reagents, to remove oligonucleotide phosphotriester intermediates intact from a solid support, and to conduct block syntheses in solution or on a silica support viaphosphite chemistry. Deprotection can be achieved by warming the trihaloethyl phosphotriesters with tributylphosphine. The high efficiency of the coupling and deprotection reactions for oligomers bound to an insoluble support make this chemistry especially attractive.     

Functionalized fluorenes via dicationic electrophiles

Dicationic fluorenyl cations are shown to react with nitriles to provide amide-functionalized fluorenes. A similar reaction with alcohols gives ether derivatives. The chemistry is initiated by the reactions of N-heterocyclic ketones in a superacidic solution. This leads to cyclizations involving 2-biphenyl groups and formation of the reactive fluorenyl cations.     

A new (R)-hydroxynitrile lyase from Prunus mume: asymmetric synthesis of cyanohydrins

A new hydroxynitrile lyase (HNL) was isolated from the seed of Japanese apricot (Prunus mume). The enzyme has similar properties with HNL isolated from other Prunus species and is FAD containing enzyme. It accepts a large number of unnatural substrates (benzaldehyde and its variant) for the addition of HCN to produce the corresponding cyanohydrins in excellent optical and chemical yields. A new HPLC based enantioselective assay technique was developed for the enzyme, which promotes the addition of KCN to benzaldehyde in a buffered solution (pH=4.5).     

晚清时期译日化学教科书述评*——以1907年版《中等最新化学教科书》为例

晚清时期由日本吉田彦六郎著、何燏时翻译的《中等最新化学教科书》是癸卯学制颁布后第一本较有影响的译日中等学校化学教科书。从出版背景发现其是效法日本教育的产物,内容体系意在传递给学生较完备的化学知识,化学名词术语翻译趋向标准化,晚清时期译日化学教科书使我国中学化学教材的编制上升了一个新台阶。     

Optimization of spiroimidazolidinone derivatives synthesis on solid phase using SynPhase™ Lanterns

We report the synthesis of 1,4,8-triazaspiro[4.5]decan-2-one derivatives from N-benzyl-4-piperidone and N-protected amino acid amides on solid support. We have translated the chemistry from solution to solid phase using a backbone amide linker (BAL) mimic. Using a parallel combinatorial approach, we performed the optimization of the synthesis on SynPhase™ Lanterns.     

Self-assembly of graphene oxide nanosheets in t-butanol/water medium under gamma-ray radiation

Graphene oxide (GO) nanosheets dispersed in strong acidic t-butanol/water medium can be reduced and self-assembled into a self-standing graphene hydrogel under γ-ray radiation, providing a facile and economical preparation method for hydroxylalkylated graphene-based aerogel.     

Fundamental problems of the chemistry of supramolecular and nanosized structures

A series of problems presently being solved in the framework of two new complementary directions of chemistry, viz., supramolecular chemistry and chemistry of nanosized systems, which have been formed and intensively developed for the recent 2–3 decades, are discussed.     

From chemical topology to molecular machines

The chemistry of molecules displaying novel topologies has experienced an explosive development in the course of the last 25 years. The fast growth of this field originates to a large extent from the new templated synthetic methods which allow one to prepare these compounds at a real macroscopic level. Our group, in particular, has proposed a particularly efficient copper(I)-based template synthesis of a large variety of catenanes and rotaxanes at an early stage, participating in the revival of molecular topology. One of the highlights of the field has been the synthesis of the trefoil knot, a particularly challenging target. This object is not only an aesthetically attractive molecule but it also displays interesting properties in relation to coordination chemistry and chirality. A highly promising extension of molecular topology is that of molecular machines. By combining the specific properties of catenanes and rotaxanes, i.e., marked flexibility and propensity to undergo large amplitude motions, and coordination chemistry, it has been possible to elaborate and study a large variety of molecular machines. A recent example is that of an adjustable receptor, based on a [3]rotaxane attached to two mobile porphyrinic plates. This compound and related molecules will lead to “molecular presses” and, eventually, to molecular machines usable in solution to catalyse reactions or change the conformation of given substrates.     

Prediction of aqueous solubilities of solid carboxylic acids with COSMO-RS

The methodology for the prediction of aqueous solubilities of solid organic compounds, and their temperature dependence, based on the Conductor-like Screening Model for Real Solvents (COSMO-RS/COSMOtherm) procedure, is presented and evaluated. The predictive capability of the quantum chemistry based program and the applied methodology was tested on the most common solid carboxylic acids. From the temperature dependence of the solubilities, the mean apparent enthalpies of solution were derived. The results obtained for a set of 27 carboxylic acids, consisting of aromatic carboxylic acids, dicarboxylic acids, as well as hydroxycarboxylic acids, are in good agreement with the experimental solubility data and their dependence with the temperature. The mean apparent enthalpies of solution, although of the same order of magnitude of the experimentally values, seem to be systematically underestimated.     

Stabilization of hydrated AcIII cation: the role of superatom states in actinium-water bonding

²²⁵Ac-based radiopharmaceuticals have the potential to become invaluable in designated cancer therapy. However, the limited understanding of the solution chemistry and bonding properties of actinium has hindered the development of existing and emerging targeted radiotherapeutics, which also poses a significant challenge in the discovery of new agents. Herein, we report the geometric and electronic structural properties of hydrated Ac^III cations in the [Ac^III(H₂O)_n]³⁺ (n = 4–11) complexes in aqueous solution and gas-phase using density functional theory. We found that nine water molecules coordinated to the Ac^III cation is the most stable complex due to an enhanced hydration Gibbs free energy. This complex adopts a closed-shell 18-electron configuration (1S²1P⁶1D¹⁰) of a superatom state, which indicates a non-negligible covalent character and involves H₂O → Ac^III σ donation interaction between s-/p-/d-type atomic orbitals of the Ac atom and 2p atomic orbitals of the O atoms. Furthermore, potentially existing 10-coordinated complexes need to overcome an energy barrier (>0.10 eV) caused by hydrogen bonding to convert to 9-coordination. These results imply the importance of superatom states in actinide chemistry generally, and specifically in Ac^III solution chemistry, and highlight the conversion mechanism between different coordination numbers.

The stable 9-coordinated complex adopts a closed-shell 18-electron configuration of a 1S²1P⁶1D¹⁰ jellium state, while potential 10-coordinated complexes need to overcome an energy barrier (>0.10 eV) caused by hydrogen bonding to convert to 9-coordination.     

The preparation and selected properties of Mg-doped p-type iron oxide as a photocathode for the photoelectrolysis of water using visible light

Stable Mg-doped iron oxides that exhibit p-type character have been synthesized. These have been utilized in the form of sintered polycrystalline disks for the photodissociation of water. We report the influence of sintering temperature, surface oxygen deficiency, Mg-doping level, and solution chemistry on the photoactivity of the Mg-doped iron oxide photocathodes.     

Immobilization of proteins on carboxylic acid functionalized nanopatterns

The immobilization of proteins on nanopatterned surfaces was investigated using in situ atomic force microscopy (AFM) and ex situ infrared reflectance–absorption spectroscopy (IRAS). The AFM-based lithography technique of nanografting provided control of the size, geometry, and spatial placement of nanopatterns within self-assembled monolayers (SAMs). Square nanopatterns of carboxylate-terminated SAMs were inscribed within methyl-terminated octadecanethiolate SAMs and activated using carbodiimide/succinimide coupling chemistry. Staphylococcal protein A was immobilized on the activated nanopatterns before exposure to rabbit immunoglobulin G. In situ AFM was used to monitor changes in the topography and friction of the nanopatterns in solution upon protein immobilization. Complementary studies with ex situ IRAS confirmed the surface chemistry that occurred during the steps of SAM activation and subsequent protein immobilization on unpatterned samples. Since carbodiimide/succinimide coupling chemistry can be used for surface attachment of different biomolecules, this protocol shows promise for development of other aqueous-based studies for nanopatterned protein immobilization.     

Solution Coordination Chemistry of Organotin(IV) Cations with Bio-relevant Ligands

A comprehensive review of organotin(IV) ⁿ⁺ hydrolysis and complex formation equilibria with amino acids, peptides and DNA constituents is presented with special reference to solution and coordination chemistry studies. The review focuses on results obtained in the author??s laboratory and related work of other groups. Also, published studies on these complexes were reviewed with emphasis on their biological aspects.     

Synthesis of S-glycosyl amino acids and S-glycopeptides via photoinduced click thiol-ene coupling

We report on the photoinduced addition of glycosyl thiols to alkenyl glycines (thiol-ene coupling) to give S-glycosyl amino acids in high yields (53-90%). One of the amino acids thus prepared was used in the construction of a tripeptide via solution phase chemistry. Moreover, a one-pot two-step approach to an S-glycopeptide was developed using glutathione (GSH) as model starting material. This approach involved GSH S-alkenylation followed by photoinduced hydrothiolation by a glycosyl thiol.