Volume 82, Issue 12

Among many global responsibilities, IUPAC recognizes in particular the importance of encouraging, supporting, and fostering the career development of young scientists throughout the world. The imminent International Year of Chemistry 2011 (IYC 2011) is a very special period not only for IUPAC but also for the whole world chemistry community. IYC 2011 was declared by the UN General Assembly in December 2008, to celebrate the achievements of chemistry and its contributions to the well-being of humankind. Under the theme “Chemistry - our life, our future”, IYC 2011 will offer a wide range of interactive activities across the globe. IUPAC feels strongly that encouragement of young research scientists is critical to the future of chemistry. Therefore, one of the most important aims of IYC 2011 is to increase the interest of young people in chemistry. Since 2000, IUPAC has sought to encourage outstanding young research chemists at the beginning of their careers by making annual awards of the IUPAC Prize for Young Chemists. The prizes are given for the most outstanding Ph.D. theses in the area of the chemical sciences, as described in 1000-word essays. For details, please refer to IUPAC Prizes for Young Chemists. IUPAC awards up to five prizes annually, each comprising USD 1000 and travel expenses to the next IUPAC Congress. As immediate Past President of IUPAC, I was honored to chair the prize selection committee of eminent chemists, who enjoyed reading essays of 29 applicants from 15 countries. After critical evaluation of the originality and excellence of the essays, the committee decided unanimously to award 2010 Prizes to the following five chemists: - Guangbin Dong , Stanford University, Palo Alto, CA, USA: “Synthetic efficiency: Using atomeconomical and chemoselective approaches towards total syntheses of Agelas alkaloids, terpestacin, and bryostatins” - Viktoria Gessner , Technical University Dortmund, Dortmund, Germany: “Lithium-organic compounds: From the structure–reactivity relationship to versatile synthetic building blocks and their application” - Rafal Klajn , Northwestern University, Evanston, IL, USA: “Self-assembly of nanostructured materials” - Jason M. Spruell , Northwestern University, Evanston, IL, USA: “Molecular recognition and switching via radical dimerization” - Guihua Yu , Harvard University, Cambridge, MA, USA: “Assembly and integration of semiconductor nanowires for functional nanosystems” The 43rd IUPAC World Chemistry Congress will take place in San Juan, Puerto Rico, 30 July-7 August 2011. Each awardee is invited to present a poster on his/her research and to participate in a plenary award session. The prize winners are also invited to offer review papers on their research topics for consideration as publications in Pure and Applied Chemistry (PAC) . Four of the five winners have taken advantage of this offer, and their refereed articles appear in this issue of PAC . Finally, it is an honor and a pleasure to congratulate each of the winners and their supervisors for winning the 2010 IUPAC Prize for Young Chemists. It is hoped that each of them will continue to contribute to a bright future for chemical sciences and technologies. Jung-Il Jin IUPAC Immediate Past President and Chair of the IUPAC Prize Selection Committee

Agelastatins represent an important family of marine alkaloids in terms of both exceptional biological activity and intriguing chemical structure. In this article, the isolation and biological activity of agelastatins are reviewed, and proposed biosynthetic pathways are summarized. The main focus is given to comparative evaluation of recent total syntheses, mainly of agelastatin A. To date, this has been accomplished by 11 research groups. Their synthetic routes are analyzed and summarized, with a view to furnishing the reader with insight into different strategic design approaches to assembly of a densely functionalized and compact structure.

The immobilization of molecular switches onto inorganic supports has recently become a hot topic as it can give rise to novel hybrid materials in which the properties of the two components are mutually enhanced. Even more attractive is the concept of “transferring” the switchable characteristics of single layers of organic molecules onto the underlying inorganic components, rendering them responsive to external stimuli as well. Of the various molecular switches studied, azobenzene (AB) has arguably attracted most attention due to its simple molecular structure, and because its “trigger” (light) is a noninvasive one, it can be delivered instantaneously, and into a precise location. In order to fully realize its potential, however, it is necessary to immobilize AB onto solid supports. It is the goal of this manuscript to comprehensively yet concisely review such hybrid systems which comprise AB forming well-defined self-assembled monolayers (SAMs) on planar and curved (colloidal and nanoporous) inorganic surfaces. I discuss methods to immobilize AB derivatives onto surfaces, strategies to ensure efficient AB isomerization, ways to monitor the switching process, properties of these switchable hybrid materials, and, last but not least, their emerging applications.

This article highlights the emerging use of the interactions of radical π-dimers to drive both molecular recognition and switching processes within supramolecular systems and mechanically interlocked molecular architectures. The enhanced stability experienced by dimers of radical cation species when encapsulated, as compared to when they are free in solution, is driving their useful incorporation into functional systems. The redox stimulation used in the production of radical cation species provides the ideal trigger for molecular switching events. Moreover, the nature and strength of the radical dimerization events introduces a completely novel recognition motif within supramolecular and mechanically interlocked molecular systems, complementing well-established techniques and enabling new research opportunities to blossom.

Central to the bottom-up paradigm of nanoscience, which could lead to entirely new and highly integrated functional nanosystems, is the development of effective assembly methods that enable hierarchical organization of nanoscale building blocks over large areas. Semiconductor nanowires (NWs) represent one of the most powerful and versatile classes of synthetically tunable nanoscale building blocks for studies of the fundamental physical properties of nanostructures and the assembly of a wide range of functional nanoscale systems. In this article, we review several key advances in the recent development of general assembly approaches for organizing semiconductor NW building blocks into designed architectures, and the further integration of ordered structures to construct functional NW device arrays. We first introduce a series of rational assembly strategies to organize NWs into hierarchically ordered structures, with a focus on the blown bubble film (BBF) technique and chemically driven assembly. Next, we discuss significant advances in building integrated nano-electronic systems based on the reproducible assembly of scalable NW crossbar arrays, such as high-density memory arrays and logic structures. Lastly, we describe unique applications of assembled NW device arrays for studying functional nanoelectronic–biological interfaces by building well-defined NW-cell/tissue hybrid junctions, including the highly integrated NW–neuron interface and the multiplexed, flexible NW–heart tissue interface.

Chromophore-based fluorescence standards for the characterization of photo-luminescence measuring systems and the determination of relevant fluorometric quantities are classified according to their scope and area of application. General and type-specific requirements for suitable standards are derived for each class of standards. Metrological requirements linked to the realization of comparable measurements are addressed and recommendations on selecting, using, and developing fluorescence standards are given.