充满生机和科学机遇的磷化学研究所

简要地综述了第十五届国际磷化学会议的报告内容，介绍了目前磷化学的主要 研究领域，包括不对称合成、配合化学，生物碱化学，药物化学，农业化学等相关 领域的研究动态及新进展。     

Novel arylpyridine‐based 1,3,4‐oxadiazoles: Synthesis,antibacterial, and anti‐inflammatory evaluation

In view of developing novel bioactive compounds, a series of 2‐(5‐[2‐methyl‐6‐arylpyridin‐3‐yl]‐1,3,4‐oxadiazol‐2‐ylthio)‐1‐arylethanones (6a–n) were designed and synthesized in good yield. Novel compounds were evaluated for their antibacterial and anti‐inflammatory activities. All synthesized compounds were screened for their antibacterial activity against Staphylococcus aureus, Bascillus subtilis, Eschericia coli, and Pseudomonas aeruginosa strains. Compounds 6a , 6b , 6c , 6h , and 6i displayed the highest antibacterial activity with minimal inhibitory concentration (MIC) values ranging from 6.25–12.5 μg/mL in comparison with the standard Ciprofloxacin. The results of anti‐inflammatory activity of carrageenan‐induced footpad edema assay indicated that tested compounds exhibited remarkable anti‐inflammatory activity with percentage of inhibition of 63.9–70.1% (potency 96.8–106.20% of indomethacin activity) after 3 hr. Particularly, 6c – e and 6j – l were found to be excellent inhibitors of inflammation, with potential higher than that of the standard, Indomethacin.     

Pharmaceutical Chemistry Today—Changes,Problems, and Opportunities

Dissatisfaction with empirical methods, high expectations of the public, poorly harmonized international regulations, and rising costs have induced pharmaceutical research to search for new approaches. As a consequence, the medicinal chemist's professional activity is in a state of change. His synthetic strategy is being increasingly influenced by the reasoning of molecular biology. Novel classes of biologically active compounds demand the development of new synthetic methods beyond the scope of modern preparative organic chemistry: enzymes and microorganisms, cell cultures, and genetic engineering are harnessed to supply highly complex structures. Major efforts are devoted to the development of reliable structure-activity relationships to rationalize his work. Thus the field of medicinal chemistry stretches from physical and physical organic chemistry far into the realm of biosciences, and the interdisciplinary character of this research is rapidly increasing. The author endeavors to convey an impression of this complex subject with the aid of selected examples.     

Effect of titanium,antimony, and ruthenium doping on tin dioxide adsorption properties. Quantum-chemical modeling

The influence of the composition of oxides supports on the specific electroactive surface area of Pt in the catalysts, the platinum nanoparticles dispersion, and Pt contents in the catalysts was studied. The Sb-doped SnO₂ oxides with various Sb-doping levels were prepared as a supports of platinum catalysts in polymer electrolyte membrane fuel cells. Density functional theory simulation of Ti, Sb, and Ru doping of tin dioxide and interaction of the doped surfaces with platinum cluster Pt₁₉ have been carried out. All calculations were performed in PBE exchange–correlation functional, with periodic boundary conditions and projector-augmented waves (PAW) basis set. The calculation results were compared with the experimental data X-ray diffraction and transmission electron microscopy (TEM). It was shown that Sb doping of tin dioxide (in quantity of less than 10%, that is, the quantity which cannot provoke significant defects of crystal structure of the supports) leads to a significant increase in a number of platinum clusters adsorbed from the colloidal solution onto the supports surface which results to an increase of the platinum cluster interaction with the supports. The calculated and experimental results are in close fit.     

Multifunctional "clickates" as versatile extended heteroaromatic building blocks: efficient synthesis via click chemistry, conformational preferences, and metal coordination

Click chemistry has been utilized to access 2,6-bis(1-aryl-1,2,3-triazol-4-yl)pyridines (BTPs) as versatile extended heteroaromatic building blocks for their exploitation in supramolecular chemistry, in particular foldamer and ligand design. In addition to their high-yielding synthesis using Cu(I)-catalyzed Huisgen-type 1,3-dipolar cycloaddition reactions the formed triazole moieties constitute an integral part of the BTP framework and encode both its pronounced conformational preferences as well as its chelating ability. A diverse set of symmetrical and non-symmetrical BTPs carrying electron-donating and -withdrawing substituents at both terminal aryl and the central pyridine moieties has efficiently been synthesized and could furthermore readily be postfunctionalized with amphiphilic side chains and porphyrin chromophores. In both solution and solid state, the BTP scaffold adopts a highly conserved horseshoe-like anti-anti conformation. Upon protonation or metal coordination, the BTP scaffold switches to the chelating syn-syn conformation. Iron and europium complexes have been prepared, successfully characterized by single-crystal X-ray diffraction analysis, and investigated with regard to their spin state and luminescent properties. The extended heteroaromatic BTP scaffold should prove useful for the design of responsive foldamer backbones and the preparation of new magnetic and emissive materials.     

Pt(II) Complexes with Azolate‐containing Bidentate Chelate: Design,Photophysics, and Application

This review is aimed at the current research progression of a unique class of Pt(II ) metal complexes bearing at least one azolate‐containing bidentate chelate. The azole fragment can link to a neutral heteroaromatic entity or another azole and form bidentate chelates, such as monoanionic 3‐pyridyl‐1H ‐pyrazole and derivatives, dianionic 3,3′‐bi‐1H ‐pyrazole, 3,3′‐(1‐methylethylidene)‐bis‐1H ‐pyrazole, and their analogs. These azole‐containing chelates readily react with a variety of Pt(II) reagents to afford the corresponding bis‐bidentate Pt(II) complexes. Most of them were highly emissive in solution, doped polymer matrix, thin film, and even as crystal or powder, due to the high ligand field strength exerted by these chelates and their high propensity in forming the singular square‐planar architecture and intermolecular aggregates with substantially strengthened Pt⋯Pt interaction, according to their structural design. Therefore, they hold bright prospects in academic research and future optoelectronic applications such as organic light‐emitting diodes.     

Disulfides, imines, and metal coordination within a single system: interplay between three dynamic equilibria

We report a system in which three distinct dynamic linkages, disulfide (S-S), imine (C=N), and coordinative (N-->metal) bonds were shown to be capable of simultaneous reversible exchange. The "disulfide layer" of the system under study consists of two homo-disulfides, bis(4-aminophenyl) disulfide 1 and bis(4-methoxyphenyl) disulfide 2 that equilibrate in the presence of catalytic amount of triethylamine to favor the formation of a hetero-disulfide product, 4-aminophenyl-4'-methoxyphenyl disulfide 3. The addition of 2-formylpyridine and a metal salt strongly perturbed this 1+2<-->3 equilibrium through the formation of metal complexes incorporating disulfide 1 as a subcomponent. CuI perturbed the equilibrium by a factor of 3.3, and FeII by a factor of 179, in both cases in favor of the homo-disulfides. The disulfide equilibrium could be further modified, following metal-complex formation, by coordinative (transmetallation: substitution of FeII for CuI) or covalent (imine exchange: the substitution of one amine residue for another) exchange. Thus, although the three kinds of dynamic linkages were demonstrated to be mutually compatible, changes at one kind of linkage could be used to predictably perturb an equilibrium involving another.     

Synthesis of symmetrically and unsymmetrically substituted S,S-dialkyl phosphonodithioates

Herein, we report the synthesis of a range of S,S-dialkyl phosphonodithioates. Symmetrically substituted analogues were readily prepared from the corresponding phosphonic dichlorides in good to moderate yields, while unsymmetrically substituted variants were obtained by a sequential alkylation-deprotection-alkylation strategy.     

Synthesis, structural features, absorption spectra, redox behaviour and luminescence properties of ruthenium(ii) rack-type dinuclear complexes with ditopic, hydrazone-based ligands

The isomeric bis(tridentate) hydrazone ligand strands 1 a-c react with [Ru(terpy)Cl3] (terpy=2,2':6',2'-terpyridine) to give dinuclear rack-type compounds 2 a-c, which were characterised by several techniques, including X-ray crystallography and NMR methods. The absorption spectra, redox behaviour and luminescence properties (both in fluid solution at room temperature and in rigid matrix at 77 K) of the ligand strands 1 a-c and of the metal complexes 2 a-c have been studied. Compounds 1 a-c exhibit absorption spectra dominated by intense pi-pi* bands, which, in the case of 1 b and 1 c, extend within the visible region, while the absorption spectra of the rack-type complexes 2 a-c show intense bands both the in the UV region, due to spin-allowed ligand-centred (LC) transitions, and in the visible, due to spin-allowed metal-to-ligand charge-transfer (MLCT) transitions. The energy position of these bands strongly depends on the ligand strand: in the case of 2 a, the lowest energy MLCT band is around 470 nm, while in 2 b and 2 c, it lies beyond 600 nm. Ligands 1 a-c undergo oxidation processes that involve orbitals based mainly on the CH3--N--N== fragments. The complexes 2 a-c undergo reversible metal-centred oxidation, while reductions involve the hydrazone-based ligands: in 2 b and 2 c, the bridging ligand is reduced twice and in 2 a once before reduction of the peripheral terpy ligands takes place. Ligands 1 a-c exhibit luminescence from the lowest-lying 1pi-pi* level. Only for complex 2 a does emission occur; this may be attributed to a 3MLCT state involving the bridging ligand. Taken together, the results clearly indicate that the structural variations introduced translate into interesting differences in the spectroscopic, luminescence and redox properties of the ligand strands as well as of the rack-type metal complexes.     

ChemInform Abstract: Complexes of Sulfuric Acid with Hydrogen Chloride,Water, Nitric Acid,Chlorine Nitrate,and Hydrogen Peroxide: An ab initio Investigation.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

Diphenylberyllium Reinvestigated: Structure,Properties, and Reactivity of BePh2, [(12-crown-4)BePh]+, and [BePh3]−

The first synthesis of BePh₂ was accomplished almost a century ago. However, its structure has remained unknown so far, while the corresponding aryls of the elements adjacent to beryllium in the periodic table are well investigated. Herein, we present an improved synthesis for diphenylberyllium and show by X-ray diffraction that it forms a trinuclear complex in the solid state. NMR spectroscopy revealed that this structure is also retained in solution but exhibits dynamic behavior. Its stability against heat and coordinating solvents is discussed and the possible obstacles to the synthesis of BePh₂ from BeCl₂ are examined. In the process of this study two ether adducts, BePh₂⋅Et₂O and Be₂Ph₄⋅Et₂O, have been characterized as well as the previously unknown triphenylberyllate anion. From the latter several single-crystal structures were obtained under various conditions, in which [BePh₃]⁻ is either isolated or acts as a ligand for Li⁺. Furthermore, the crown ether induced selfionization of BePh₂ is described and the resulting [(12-crown-4)BePh]⁺ cation was isolated, which shows an unusual 4+1 coordination around the Be atom.     

Catalytic,Mild, and Selective Oxyfunctionalization of Linear Alkanes: Current Challenges

Selective catalysts for sustainable oxidation of alkanes are highly demanded because of the abundance of these molecules in the environment, the possibility to transform them into higher‐value compounds, such as chemicals or synthetic fuels, and the fact that, kinetically speaking, this is a difficult reaction. Numerous chemical and biological catalysts have been developed in the lasts decades for this purpose, rendering the overview over this field of chemistry difficult. After giving a definition of the ideal catalyst for alkane oxyfunctionalization, this review aims to present the catalysts available today that are closest to ideal.     

The Relationship of William Henry Perkin,Jr. and Sir Robert Robinson: Teacher and Student,then Student and Teacher

William Henry Perkin, Jr. FRS, the son of the inventor of mauve and other commercial dyes and credited for initiating the industrialization of chemistry, was himself a notable chemist. He was the Professor of Organic Chemistry at Manchester from 1892–1912 and then was the Waynflete Professor of Chemistry at Oxford and the first Head of the Dyson Perrins Laboratory from 1912–1929. One of Perkin's graduate students and research assistants at Manchester was Robert Robinson, subsequently Sir Robert Robinson, FRS and recipient of the 1947 Nobel Prize in Chemistry. Perkin and Robinson had perhaps the most productive and broad collaboration between a professor and one's student. Together, during and after Robinson's student days, they had 71 joint publications, 25 of which involved just the two of them, 17 of which involved the structure determination of strychnine, and eight of which were published after Perkin's death in 1929. Upon Perkin's early death, Robinson succeeded him as the fourth Waynflete Professor of Chemistry at the Dyson Perrins Laboratory, Oxford University. This Essay will examine the professional relationship of Perkin, Jr. and Robinson as revealed in their joint publications on the structure of strychnine.     

Planar,Stair-Stepped,and Twisted: Modulating Structure and Photophysics in Pyrene- and Benzene-Fused N-Heterocyclic Boranes

Because of their rigidity, polycyclic aromatic hydrocarbons (PAHs) have become a significant building block in molecular materials chemistry. Fusion or doping of boron into PAHs is known to improve the optoelectronic properties by reducing the LUMO energy level. Herein, we report a comprehensive study on the syntheses, structures, and photophysical properties of a new class of fused N-heterocyclic boranes (NHBs), pyrene- and benzene-linked in a “Janus-type” fashion ( 2 – 4 , 6 – 9 , and 11 ). Remarkably, these examples of fused NHBs display fluorescent properties, and collectively their emission spans the visible spectrum. The pyrene-fused NHBs all display blue fluorescence, as the excitations are dominated by the pyrene core. In notable contrast, the emission properties of the benzene-fused analogues are highly tunable and are dependent on the electronics of the NHB fragments (i.e., the functional group directly bound to the boron atoms). Pyrene-fused 2 – 4 and 11 represent the only molecules in which the K-region of pyrene is functionalized with NHB units, and while they exhibit distorted (twisted or stair-stepped) pyrene cores, benzene-fused 6 – 9 are planar. The electronic structure and optical properties of these materials were probed by computational studies, including an evaluation of aromaticity, electronic transitions, and molecular orbitals.