When considering new sensory technologies one should look to nature for guidance. Indeed, living organisms have developed the ultimate chemical sensors. Many insects can detect chemical signals with perfect specificity and incredible sensitivity. Mammalian olfaction is based on an array of less discriminating sensors and a memorized response pattern to identify a unique odor. It is important to recognize that the extraordinary sensory performance of biological systems does not originate from a single element. In actuality, their performance is derived from a completely interactive system wherein the receptor is served by analyte delivery and removal mechanisms, selectivity is derived from receptors, and sensitivity is the result of analyte-triggered biochemical cascades. Clearly, optimal artificial sensory sys-

Conjugated polymer-based chemical sensors.

/pdf/aryl-aryl-bond-formation-one-century-after-the-discovery-of-1jdyxlkwix.pdf

Aryl-aryl bond formation one century after the discovery of the Ullmann reaction.

The widespread use of controlled molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular systems, which by and large rely upon electronic and chemical effects to carry out their functions, and the machines of the macroscopic world, which utilize the synchronized movements of smaller parts to perform specific tasks. This is a scientific area of great contemporary interest and extraordinary recent growth, yet the notion of molecular-level machines dates back to a time when the ideas surrounding the statistical nature of matter and the laws of thermodynamics were first being formulated. Here we outline the exciting successes in taming molecular-level movement thus far, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion. We also highlight some of the issues and challenges that still need to be overcome.

Synthetic molecular motors and mechanical machines.

Synthetic Principles for Bandgap Control in Linear pi-Conjugated Systems.

Electrochemical energy storage systems (batteries) have a tremendous role in technical applications In this review the authors examine the prospects of electroactive polymers in view of the properties required for such batteries Conducting organic polymers are considered here in the light of their rugged chemical environment: organic solvents, acids, and alkalis The goal of the present article is to provide, first of all in tabular form, a survey of electroactive polymers in view of potential applications in rechargeable batteries It reviews the preparative methods and the electrochemical performance of polymers as rechargeable battery electrodes The theoretical values of specific charge of the polymers are comparable to those of metal oxide electrodes, but are not as high as those of most of the metal electrodes normally used in batteries Therefore, it is an advantage in conventional battery designs to use the conducting polymer as a positive electrode material in combination with a negative electrode such as Li, Na, Mg, Zn, MeH{sub x}, etc 504 refs

Electrochemically Active Polymers for Rechargeable Batteries.

Two series of thiophene monomers 3-substituted with linear and branched alkyl chains have been synthesized, and their electropolymerization has been investigated together with the properties of the resulting polymers. An analysis of the effects of the electrosynthesis conditions by visible absorption spectroscopy shows that the mean conjugation length presents an increasing dependence on the applied electrical conditions as the length of the alkyl chain increases. In the case of linear alkyl substituents (R3 = CH/sub 3/ to C/sub 18/H/sub 37/), the length of the alkyl chain affects slightly the polymerization reaction but produces important modifications on the structure and on the properties of the polymers. Thus, the mean conjugation length and the electrochemical reversibility admit an optimum for the polymers containing 7-9 carbons in the alkyl chain while the polymer films remain highly conductive up to R3 = C/sub 10/H/sub 21/. In contrast, the steric hindrance to conjugation caused by branched alkyl substituents totally inhibits the polymerization (isopropyl) or leads to weakly conjugated polymers (isobutyl). It is shown that the distance between the thiophene ring and the branched alkyl chain is the determining parameter which governs the aptitude for electropolymerization and the properties of the resulting polymer.

Effects of steric factors on the electrosynthesis and properties of conducting poly(3-alkylthiophenes)

Poly mono-, bi- and trithiophene: effect of oligomer chain length on the polymer properties

Chiral poly(thiophenes) have been synthesized by electropolymerization; they exhibit high specific rotation, stability, and conductivity and can stereoselectively recognize chiral anions used as doping agents during voltammetric cycles.

Enantioselective chiral poly(thiophenes)

Poly[3-(3,6-dioxaheptyl)thiophene] has been synthesised by electropolymerisation; this highly conducting electroactive polymer exhibits specific interactions with lithium cations.

Robert Garreau

Papers

Effects of steric factors on the electrosynthesis and properties of conducting poly(3-alkylthiophenes)

Poly mono-, bi- and trithiophene: effect of oligomer chain length on the polymer properties

Enantioselective chiral poly(thiophenes)

Modification of the structure and electrochemical properties of poly(thiophene) by ether groups

A molecular approach of poly(thiophene) functionalization