Band 78, Heft 5

"Creativity is the soul of a nation and an inexhaustible source of a country's prosperity." Original innovation, as the major source of new technologies, will not only bring about technological breakthroughs, but give rise to new industries and new economic structures, offering unlimited opportunities for later starters to overtake the frontrunners. "Innovation in Chemistry" is the specific theme for the 40th International Union of Pure and Applied Chemistry (IUPAC) Congress, which was held on 14-19 August 2005 in Beijing, China. The Congress provided an excellent forum for presenting the latest innovative achievements in the chemical sciences and in the practice of chemistry. A total of 1083 participants from 64 countries attended the Congress. With 412 of the participants from mainland China and 556 from other countries and regions, the Congress helped to build a bridge between Chinese chemists and the world, encouraging cooperation and excellence in fundamental research and industrializations. The high-scientific value of the Congress was evident in the plenary lectures, which were delivered by eight distinguished chemists, including three Nobel Laureates and one Einstein Award Winner. A total of 1145 papers and 622 posters were presented in the eight sessions of the Congress: (1) Environmental Chemistry and Green Chemistry; (2) Chemistry in the Life Sciences and Chemical Biology; (3) Materials Chemistry, Supermolecular Chemistry, and Nanochemistry; (4) Information Technology in Chemistry and Computational Chemistry; (5) Innovation in Physical Chemistry and Biophysical Chemistry: Research Methods and Techniques; (6) Innovation in Methodology, Technique, and Instrumentation and Analytical Chemistry; (7) Innovation in Chemical Education and Teaching Methods; (8) Innovation in the Chemical and Petrochemical Industries and "Responsible Care" for Society. Fourteen papers selected from the plenary and invited lectures from the 40th IUPAC Congress are published in this special issue of Pure and Applied Chemistry (PAC) , which cover a spectrum from theoretical chemistry to chemical engineering, from micro/nanoscale studies to industrial-scale process/equipment evaluations. The review on the study of single molecules and their assembly provides a comprehensive, up-to-date summary of the field based on the fundamental research; much of the information presented falls within the special expertise of the group. The paper on the superheavy element describes the latest developments in a field that has shown higher activity in recent years as the predicted "island of stability" comes within the reach of the available hardware. This area is always of special interest to international scientists owing to the special synthesis techniques for superheavy elements employed by the Dubna group. Green chemistry is becoming a characteristic area in China that plays a significant role in motivating the development of new synthetic techniques, such as cross-dehydrogenative coupling. Other papers in this issue address a variety of topics from novel instrumentation for electrochemical impedance spectroscopy to synthesis of oxide nanomaterials; from catalysts to waste water treatment. These papers give a snapshot of the research reported at the 40th IUPAC Congress. I sincerely hope that this special issue of PAC brings some fresh ideas, novel concepts, and useful data to the readers. The International Organizing Committee contributed to the shaping of an important area of emerging science and technology. Thanks and appreciations are due to the Local Organizing Committee for the efficiency and excellence of the local arrangements and for the gracious hospitality. I am grateful to those who contributed their latest research work to this issue, and the support from Dr. John W. Jost, IUPAC Executive Director. Chunli Bai President of the 40th IUPAC Congress, President of the Chinese Chemical Society, and Executive Vice President of the Chinese Academy of Sciences

A fundamental outcome of modern nuclear theory is the prediction of the "island of stability" in the region of hypothetical superheavy elements. A significant enhancement in nuclear stability at approaching the closed shells with Z = 114 (possibly 120 and 122) and N = 184 is expected for the nuclei with large neutron excess. For this reason, for the synthesis of nuclei with Z = 112-116 and 118, we chose the reactions 238 U, 242,244 Pu, 243 Am, 245,248 Cm, and 249 Cf + 48 Ca, which are characterized by fusion products with a maximal neutron excess. The formation and decay properties of the heaviest nuclei were registered with the use of a gas-filled recoil separator installed at a 48 Ca-beam of the heavy-ion cyclotron. The new nuclides mainly undergo sequential α-decay, which ends with spontaneous fission (SF). The total time of decay ranges from 0.5 ms to ~1 d, depending on the proton and neutron numbers in the synthesized nuclei. The atomic number of the new elements 115 and 113 was confirmed also by an independent radiochemical experiment based on the identification of the neutron-rich isotope 268 Db ( T SF ~ 30 h), the final product in the chain of α-decays of the odd-odd parent nucleus 288 115. The comparison of the decay properties of 29 new nuclides with Z = 104-118 and N = 162-177 gives evidence of the decisive influence of the structure of superheavy elements on their stability with respect to different modes of radioactive decay. The investigations connected with the search for superheavy elements in Nature are also presented. The experiments were carried out at the Flerov Laboratory of Nuclear Reactions (JINR, Dubna) in collaboration with the Analytical and Nuclear Chemistry Division of the Lawrence Livermore National Laboratory (USA).

The recent rapid advances in nanotechnology, especially those based on molecules, are due in large part to our newly acquired abilities to measure and manipulate individual molecules and their assemblies. Among all the approaches for the study of single molecules, scanning tunneling microscopy (STM) is unique and powerful owing to its ability to accurately probe and control single molecules. High-resolution spatial imaging combined with scanning tunneling spectroscopy (STS) helps scientists investigate and resolve many chemical and physical problems at the molecular level. In this paper, we review our recent studies of single molecules and their assemblies by combining STM experiments and theoretical simulations based on the density functional theory (DFT).

Social, economic, and environmental concerns about chemical production have been increasing. These concerns all originate from the inefficiency of conventional chemical syntheses. On the basis of the "E-factor", a concept of the "extended E-factor" is proposed in the article and is used to correlate various industrial sectors and the average number of synthetic steps involved in those sectors. Based on this analysis, the most fundamental way to eliminate waste formation is to develop new chemical reactivity that can greatly shorten the steps involved in a chemical synthesis. In classical organic transformations, a "functional group" is required. In efforts to develop new chemical reactivities that do not need extra steps for generating functional groups, we have recently developed various cross-dehydrogenative coupling (CDC) methodologies to construct functional molecules by directly using C-H bonds. This article describes the progress of our group's research endeavor.

After providing a brief overview of the various phenomena that anthropogenic organic pollutants (AOPs) of various nature and origin are subjected to in soil, the paper focuses on an important class of these, the endocrine disruptor compounds (EDCs), which are hormone-like substances able to alter (i.e.) disrupt, the normal endocrine functions in animals and humans. EDCs may enter the soil through current agricultural practices andor disposal of urban and industrial effluents, sludges, and wastes. The estrogenic risk of EDCs is generally related to their distribution and speciation in the various soil phases, in which adsorption/desorption processes play a very important role. Adsorption kinetics and adsorption/desorption isotherms of the EDCs: bisphenol A (BPA), octylphenol (OP), 17-α-ethynilestradiol (EED), and 17-β-estradiol (17ED), onto four samples collected from the surface (depth 0-30 cm) and deep (depth 30-90 cm) horizons of two acidic sandy soils in Portugal (P) and Germany (G) (P30 and G30, and P90 and G90, respectively) were determined using a batch equilibrium method and the high-performance liquid chromatography (HPLC) technique. Adsorption of EDCs onto all soils examined occurs in two phases, a rapid one in less than 10 h of contact, and corresponding to more than 90 % of total adsorption, and a slow one that may need several hours until attainment of equilibrium. Experimental adsorption data fit best in a linear isotherm for BPA, in a nonlinear, L-shaped Freundlich isotherm for EED, in either a linear or a nonlinear Freundlich isotherm for OP, and in a Langmuir isotherm for 17ED. Thus, no limiting adsorption is observed for soils examined over the concentration range tested for BPA, OP, and EED, whereas a maximum adsorption (i.e., saturation) is reached only by 17ED. In general, the values of the Freundlich constant, K , and of the distribution coefficient, K d , calculated from the experimental isotherms of the four EDCs onto soils examined follow the same trend, that is: G30 > P30 > P90 > G90. Further, the K and K d values of any EDC are positively correlated with the soil organic carbon (OC) content, which is larger for surface horizon soils than deep horizon soils. Adsorption of BPA is generally reversible, and its desorption occurs quickly and completely, thus, it is expected to move down the soil profile, and possibly contaminate the groundwater. On the contrary, OP and EED are adsorbed almost irreversibly, and are slowly and only limitedly desorbed, thus are expected to accumulate, especially in the top soil layer, and cause soil contamination.

Murine myelomonocytes WEHI-3 and human erythroid leukemia K562 cells were shown to release peptides into the surrounding medium. Four N-terminal sequences of the peptides derived from unknown protein precursors were identified in the conditioned medium of WEHI-3 culture. Twelve N-terminal sequences of the peptides released by K562 cells were established. K562 cells were shown to release long hemoglobin α- and ε-chains fragments, as well as peptides derived from carbonic anhydrase XI, melanophilin, cadherin EGF LAG G-type receptor 2, aldolase A, melastatin 1, peptide homologous to ryanodine receptor fragment, and a few peptides derived from the proteins with unknown function. Comparative analysis of the peptides released by the intact erythroid leukemia K562 cells and the same cells after differentiation (induced by guanosine monophosphate, GMP, and accompanied by start of hemoglobin biosynthesis), has demonstrated that the level of six components, including all established hemoglobin fragments, carbonic anhydrase fragment, and the fragment of the unknown protein significantly increased in the course of differentiation. The spectrum of the peptides released by K562 cells strongly differed from that of the mature erythrocytes: (1) in contrast to the mature erythrocytes, K562 cells release long α-globin fragments and the fragment of ε-globin; (2) erythrocytes almost exclusively release the products of hemoglobin proteolysis; in the case of K562 cells the fragments of enzymes, receptors, and other functional proteins were found. So, the concentration and the content of the individual peptides released by the cells depend on the differentiation state. The comparative analysis of the dynamics of peptide secretion by human erythrocytes performed in the presence and the absence of the 3 % glucose has shown that the rate of the peptide release strongly depends on cell metabolism. In summary, peptidomic studies of cell cultures provide valuable information on the mechanisms of peptide pool formation in tissues and the whole organism.

Chiral Al(salen) is used as catalyst for enantioselective cyanosilylation of aldehydes and ketones.

Our earlier investigations culminated in the discovery of a unique membrane-bound enzyme in mammalian cells catalyzing the transfer of acetyl group from polyphenolic acetates (PAs) to certain functional proteins, resulting in the modulation of their activities. This enzyme was termed acetoxy drug:protein transacetylase (TAase) since it acted upon several classes of PAs. TAase was purified from rat liver microsomes to homogeneity and exhibited the molecular weight of 55 KDa. TAase-catalyzed protein acetylation by PAs was evidenced by the demonstration of immunoreactivity of the acetylated target protein such as nitric oxide synthase (NOS) with anti-acetyl lysine. The possible acetylation of human platelet NOS by PA as described above resulted in the enhancement of intracellular levels of nitric oxide (NO). PAs unlike the parent polyphenols were found to exhibit NO-related physiological effects. The N-terminal sequence was found to show 100 % homology with N-terminal sequence of mature calreticulin (CRT). The identity of TAase with CRT, an endoplasmic reticulum (ER) protein, was evidenced by the demonstration of the properties of CRT such as immunoreactivity with anti-calreticulin, binding to Ca 2+ ions and being substrate for phosphorylation by protein kinase c (PKC), which are the hallmark characteristics of CRT. These observations for the first time convincingly attribute the transacetylase function to CRT, which possibly plays an important role in protein modification by way of carrying out acetylation of various enzymes through a biochemical mechanism independent of acetyl CoA.

The antisense or antigene properties are exerted not only by natural oligonucleotides, but also by their different analogs. Among them, phosphorothioate oligonucleotides (PS-DNA), in which the sugar-phosphate backbone is modified due to substitution of the sulfur atom for one of the nonbridging oxygens, are much more resistant toward nucleases and, simultaneously, maintain good hybridization properties. However, the substitution induces the P-chirality of dinucleoside phosphorothioate moiety and even short PS-DNA synthesized using standard chemical methods exist as a mixture of hundreds or thousands of diastereoisomers. Diastereomerically pure oligomers of [PS]-d(CG) 4 and [PS]-d(GC) 4 series, obtained using the oxathiaphospholane method, were investigated with respect to their ability to adopt the left-handed conformation at high sodium chloride concentration. Obtained data allow us to postulate the formation of a strong intramolecular hydrogen bond with anionic sulfur atom as an acceptor. Homopurine [All-R P -PS]-oligos, but not [All-S P -PS]-oligos, form with the RNA templates extremely stable triplex structures, so far not described in the literature. Most likely, the triplexes are stabilized by hydrogen bonds or water bridges with the participation of sulfur atoms of internucleotide linkage. Notably, target RNA molecules are "arrested" by properly designed [All-R P -PS]-DNA probes at submicromolar concentration, and as the result, they are not recognized by reverse transcriptase.

One-pot reaction of iron(III) acetylacetonate, Fe(acac) 3 , [or Fe(acac) 3 and M(acac) 2 where M = Mn and Co], with 1,2-alkanediol, oleic acid, and oleylamine in high boiling organic solvent leads to monodisperse ferrite MFe 2 O 4 nanoparticles. Depending on the concentration of the metal precursors, surfactant-to-metal precursor ratio and the solvent used in the reaction, the particle size from this one-pot reaction can be tuned from 4 to 15 nm. The as-synthesized iron oxide nanoparticles have an inverse spinel structure, and their magnetic properties are controlled by particle size and M in the MFe 2 O 4 structure. The hydrophobic iron oxide nanoparticles are readily transformed into hydrophilic ones by functional phospholipid addition to the as-synthesized particles and as a result, the monodisperse nanoparticles are readily functionalized with biotin, -COOH, -SH, and -NH 2 , facilitating their link to biomolecules for biomedical applications.

This presentation describes the surface micelles formed by self-organization of amphiphilic molecules at the solid/liquid interface, and reviews the methods of stabilizing the surface micelles by enhancing the intermolecular interaction or introducing covalent bonds in self-assemblies. This type of work may provide new avenues for fabricating organic nanostructure materials, as well as possible applications arising from the mimicry of biomineralization processes.

Molecular monolayers adsorbed to solid surfaces such as graphite are distinct from the bulk in their physicochemical properties because of the 2D nature. In most cases, they form a well-defined 2D crystalline solid. We have been investigating such systems of various simple molecules by means of the synergetic use of X-ray diffraction, neutron scattering, and calorimetry. Selected examples illustrate that the reduced dimensionality has important consequences for the structure, dynamics, and phase behavior in the condensed state. In some cases, the similar solid monolayers are formed at the liquid-graphite interfaces, where they also show a rich variety of the structure and phase behavior. For the multicomponent system of those monolayers, mixing behavior is particularly interesting from both the structural and thermodynamic points of view. We also investigated ice crystallization from the solution, where a 2D nature was found in structure in the initial stage of crystallization.

This contribution presents the molecular approach used to investigate the different preparation steps of important catalytic systems, based on Mo, Ni, and Co. The first preparation step consists of impregnating oxide supports by aqueous solutions of transition-metal complexes (TMCs), called precursor complexes, and involves the liquid-solid (wet) interface. The following steps consist of thermal activation treatments, involving the gas-solid (dry) interface. The molecular approach is based on (i) the use of the TMC to monitor and probe the nature of its own interactions with the oxide support, (ii) the selection of the most appropriate techniques to monitor such interactions, and (iii) the design of experiments to identify and isolate the key parameters controlling the "TMC-oxide support" interactions. Physical techniques play a key role in the characterization of catalyst preparation both at the macroscopic [temperature-programmed reduction (TPR), X-ray diffraction (XRD)] and molecular [Raman, X-ray absorption near-edge spectroscopy-extended X-ray absorption fine structure (XANES)-EXAFS, diffuse reflectance UV-vis] levels, particularly when they are used simultaneously. They give some insight into the structure of the species existing on the surface, with the oxide support behaving as a solid ligand, when exposed for a short time to the precursor complex solution or after thermal treatment, or, for longer contact times, as a reactant.

To increase the detection sensitivity of capillary electrophoresis (CE) and thereby widen its application to biomolecular analyses, we have developed a number of on-line preconcentration strategies, i.e., techniques to increase sample loading without compromising resolution and efficiency. Two such techniques, namely, dynamic pH junction and field-enhanced sample injection (FESI) are covered in this work. Dynamic pH junction is predicated on a sharp reduction in an analyte's migration velocity following a reversal of its electrophoretic direction from the acidic sample zone to the basic background solution (BGS) zone. FESI, on the other hand, depends on the retardation of analyte velocity as it transits from the low-conductivity sample zone to the high-conductivity milieu of the BGS zone. Their applications to high-sensitivity analyses of peptides and proteins are discussed.

The evolution of impedance measurement methods into the current state of the art is reviewed briefly, and recent efforts to develop new instruments to make electrochemical impedance spectroscopy (EIS) measurements faster and more accurate are described. The most recent approach for impedance measurement uses a multichannel detection technique, which is analogous to a spectroscopic measurement such as in Fourier transform infrared spectroscopy. This method, which is capable of making impedance measurements in real time during an electrochemical experiment, allows us to come up with a new integrated equation that makes a full description of an electrochemical system possible.

Herein, we describe how pesticide leaching is assessed in Europe in order to fulfill EU Directive 91/414. The assessment schemes were developed to protect groundwater from unacceptable effects caused by pesticide use. They presently focus on chromatographic flow processes, which are dominant in sandy soils. Nevertheless, important regions in Europe are characterized by structured soils where transport through macropores is most relevant. Comparison of parallel field studies with isoproturon performed in sandy and silty soils showed that maximum concentration in the structured soil at a soil depth of 1 m may exceed respective concentrations in sandy soils by a factor of 60. Similar results were obtained by lysimeter studies using silty soil cores with maximum concentration of 40 μg/l at the soil bottom. These results demonstrate that preferential flow is more the rule than the exception in well-structured fine-textured soils, and pesticide losses via macropore flow may exceed losses via matrix transport considerably. All present information available for macropore flow suggest the need for greater regional assessments. Other recommendations include analysis of the influence of different soil management practices on the formation of macropores.

In the original article.