MICROMECHANICS OF MACROELECTRONICS

The advent of flat-panel displays has opened the era of macroelectronics. Enthusiasm is gathering to develop macroelectronics as a platform for many technologies, ranging from paper-like displays to thin-film solar cells, technologies that aim to address the essential societal needs for easily accessible information, renewable energy, and sustainable environment. The widespread use of these large structures will depend on their ruggedness, portability and low cost, attributes that will come from new material choices and new manufacturing processes. For example, thin-film devices on thin polymer substrates lend themselves to roll-to-roll fabrication, and impart flexibility to the products. These large structures will have diverse architectures, hybrid materials, and small features; their mechanical behavior during manufacturing and use poses significant challenges to the creation of the new technologies. This paper describes ongoing work in the emerging field of research - the mechanics of macroelectronics, with emphasis on the mechanical behavior at the scale of individual features, and over a long time.     

2D supramolecular structures of a shape-persistent macrocycle and co-deposition with fullerene on HOPG

Two 2D supramolecular structures of macrocycle 1 and 1/C60 have been obtained on HOPG by self-assembly under ambient conditions and investigated by high-resolution STM. The monolayers of 1 are characterized by structures with perfect ordering over relatively large areas. In the case of 1/C60, the size of the macrocycle 1 and the presence of two individual bithiophene units per ring lead in the final superstructure to a 1:2 stoichiometry. The fullerenes are not trapped at the graphite surface inside the macrocyclic holes but are located around the periphery of the bithiophene units. This clearly shows that the donor-acceptor interaction between C60 and the electron-rich units of the ring is the dominant factor for the structure formation.     

Cationic shape-persistent macrocycles: the unexpected formation of a nano-size supramolecular dimer

Shape-persistent macrocycles with a rigid pyridyl core and a flexible oligo-alkyl corona aggregate to some extent in nonpolar solvents to form large (tubular) aggregates. To increase the assembling tendency, the intraannular pyridyl groups of the macrocycles were alkylated. Unexpectedly, the quarternized macrocycles show no tendency at all to form tubular micellar-like structures but form well-defined dimers, as determined by X-ray and dynamic light scattering.     

Chemie polyfunktioneller liganden: LXXIII. Synthese,struktur und reaktionsverhalten von cryptanden (bzw. spheranden) mit den heteroelementen arsen,sauerstoff, schwefel und stickstoff

The reaction of N(CH₂CH₂Cl)₃ (I) with KAs(C₆H₅)₂·dioxane ($\text{1}\text{2}$) in THF yields, as Sacconi et al. reported earlier, 80% of N[CH₂CH₂As(C₆H₅)₂]₃ (II). II is now obtained in a still higher quantity from the reaction of [HN(CH₂CH₂Cl)₃]Cl (III) with NaAs(C₆H₅)₂ in liquid ammonia. Treatment of II with gaseous HI in dry CH₂Cl₂ results in the formation of [HN(CH₂CH₂AsI₂)₃]I (IV), which is isolated by recrystallisation from THF as [HN(CH₂CH₂AsI₂)₃]I · THF ($\text{1}\text{1}$) (IVa). IVa reacts with H₂O/NH₃ or H₂S/N(C₂H₅)₃ to give the novel cryptands [N(CH₂CH₂)₃]₈-(As₄O₄)₆ (V) or [N(CH₂CH₂)₃]₈(As₄S₄)₆ (VI), which also can be denoted as spherands. The reaction of V with dry gaseous HCl in benzene leads to [HN(CH₂-CH₂AsCl₂)₃]Cl (VII). All the new compounds are characterized, as far as possible, by their IR, FIR, Raman, ¹H NMR and mass spectra. To determine the structure of V a single X-ray crystal study was carried out. Moreover II, which is already well-known but not completely characterized, is included in this discussion only for spectroscopic comparison.     

Evaporation rates of alkanes and alkanols from acoustically levitated drops

Evaporation constants of acoustically levitated drops from the homologue series of n-alkanes and 1-alkanols in ambient air have been evaluated by size and temperature measurements. The size of the pure liquid drops, within a diameter range of 0.1 to 2.5 mm, was monitored using a CCD camera, while temperature measurements were carried out by IR thermography. During drop evaporation, water from a humid environment with a relative humidity between 5 and 80% was condensed on the drop surface and in the case of n-pentane, the condensed water froze as a result of the evaporative cooling.     

Über das Kalium des Serums

Zusammenfassung Die Wanderung von Kalium, Natrium, Chlor und Eiwei? des Serums wurde in der Fürthschen Hochspannungsapparatur untersucht. Das Kalium wandert zum überwiegendenTeil anodisch. Nach Ans?uern des Serums auf p_H 4 wandert bei kathodischer Eiwei?überführung das Kalium weiter anodisch, so da? eine Bindung des im Serum befindlichen Kaliums an das Serumeiwei? bei diesem p_H nicht in Frage kommt.     

Partial correctness of exits from concurrent structures

A rudimentary exit-mechanism from the parallel command of the language fragment CSP is introduced. A method for embedding invariants in a standard partial correctness system with pre-and postconditions is presented. Proof rules for exits from concurrent systems are introduced, and a simple data flow system is verified.