The outstanding feature of materials research in the eighties has been the convergence of basic research and practical application, leading to ever shorter cycles of innovation. This is especially true of materials which form the basis of key technologies. The mass storage units of the next generations of computers will be based on optical processes having a storage density which exceeds that of all hitherto known storage techniques that are practicable from the technical standpoint. In view of the fact that since 1982 read-only memories in the form of compact discs (CD-ROM) have become very successful in the field of audio electronics, research and development are now concentrated on materials for write-once (WORM) and erasable (EDRAW) storage systems. Suitable materials for optical data storage are substances in which data markings can be recorded and deleted respectively using semiconductor lasers. Materials development is centered on the synthesis of infrared-absorbing dyes for WORM memories and the production of rare earth/transition metal alloys for magneto-optical data recording. An introduction to CD-ROM technology will be followed by an overview of the state of development of the most important storage materials which are currently available commercially, and then the properties of these materials will be discussed with reference to selected examples.

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Synthesen in der heterocyclischen Reihe, XV 2) ijber 1-[3-Aryl-isoindolyl-(l)-i1nino]-3-aryl-lH-isoindoleAus o-Cyan-benzophenon und Formamid erhalt man neben 3-Formamino-I-0x0-3-phenylisoindolin (5) das rotviolette I-[3-Phenyl-isoindolyl-(l)-imino]-3-phenyl-lH-isoindol (I).1 sowie an den Phenylkernen substituierte Analoga von 1 entstehen aus Phthalodinitrilen und Arylmagnesiumbromiden. Syntheses in the Heterocyclic Series, XVz) l-(3-Arylisoindol-l-ylimino)-3-aryl-lH-isoindoleso-Cyanobenzophenone reacts with formamide to give 3-formylamino-I-0x0-3-phenylisoindoline (5) and the redviolet 3-phenyl-l-(3-phenylisoindol-l -ylimino)-1 H-isoindole (1). Analogues of 1 substituted in the phenyl rings are obtained by treatment of phthalodinitriles with arylmagnesium bromides.

Es gibt vier Hauptverfahren des Druckens1'4! Hochdruck, Tiefdruck, Flachdruck und Durchdruck. Die Verfahren unterscheiden sich voneinander im wesentlichen durch die Eigenart der Druckform. Die Prinzipien sind in Abbildung I erlautert.Wahrend beim Hochdruck die Farbe von den erhabenen Stellen der Druckform abgenommen wird, ist es beim Tiefdruck umgekehrt: Die relativ dunnflussige Tiefdruckfarbe wird aus den Napfchen der Druckform auf das zu bedrukkende Material, z. B. Papier, ubertragen.

Dedicated to Professor Klaus Weissermel on the occasion of his 60th birthdayBesides its technical meaning, the word "electronics" signifies another industrial revolution. The driving force behind this development is the very rapid progress in the field of integrated semiconductor circuits. An ever-increasing number of structures of ever-decreasing size must be accommodated on the same surface of the semiconductor crystal. This trend towards miniaturization embraces not only the integrated circuit but also its mounting panel, the printed circuit board; integrated circuits with 65 536 storage spaces, i. e. more than 100000 individual functions, on a semiconductor die of less than 1 cm2 are already standard today in industry. This micro-world, the potential of which can hardly be fully appreciated even today, has a direct appeal to all those of scientific inclination. However, the role of chemistry in the creation of this world becomes clear only on closer examination of the manufacturing processes: no mechanical tool is fine enough and no machine is sufficiently precise and rapid to work out complicated structures in the micron range with the required perfection. Chemistry first made possible the mass production of electronic components and consequently their widespread use today, and it is chemistry which will also play a decisive role in the future. Whether in the field of photoresists for the production of printed circuit boards with conductor widths of less than 100 pm, or in overcoming the 1 pm barrier in the manufacture of semiconductors using electron beam-and X-ray-resists, photochemistry, radiation chemistry, and polymer chemistry will have to develop new manufacturing processes and provide industrially utilizable materials.