Ciba Specialty Chemicals Corporation

Roche Vitamins Inc.

Hans-Jürgen Hansen

Hansjorg Grundler

The present application describes a method for information storage and data processing comprising the steps of thermo inducing or photo inducing double-bond shifts (DBS) in substituted (4)-annulenes thus generating transitions between two different conjugation states with at least one substituent. The two different conjugation states are the conjugation on-state and conjugation off-state of the annulene core &#x3c0;-electrons with the substituent &#x3c0;-electrons. The present invention is furthermore related to novel substituted (4)-heptalenes being optically and/or thermally switchable, based on thermal or photochemical double-bond shifts (DBS) as well as methods for their preparation. The (4)-heptalenes can be used for information storage and data processing devices.

Double-bond shifts of substituted (4n)-annulenes for information storage and data processing

A process for the manufacture of 4,4-disubstituted 5-methylene-1,3-dioxolan-2-ones ('cyclocarbonates') of the formula: ##STR1## wherein R.sup.1 and R.sup.2 each independently signify a saturated or olefinically-unsaturated aliphatic group or an aromatic group, or R.sup.1 and R.sup.2 together form tetra- or pentamethylene, by reacting a corresponding 3,3-disubstituted prop-1-yn-3-ol of the formula HC.tbd.C--C(R.sup.1)(R.sup.2)--OH (II) with carbon dioxide in the presence of a quaternary ammonium or phosphonium salt as the catalyst comprises using a silver salt as a further catalyst. An alkali metal or quaternary ammonium or phosphonium salt of a carboxylic acid can also be used to increase the catalytic performance of the silver salt catalyst. Moreover, the addition of triphenylphosphine serves to accelerate the reaction to some extent. The silver salts catalyze this process significantly better than the previously utilized copper salts. Advantageously, the process uses much smaller amounts of catalyst, significantly shortens reaction times, and mandates less drastic reaction conditions. Cyclocarbonates produced by this process are valuable intermediates for the production of polymerizates and other useful substances, such as dyestuffs and carotenoids.

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Zurich, Switzerland

Hans-Jürgen Hansen