Hoechst Aktiengesellschaft

Uwe Falk

Ude Scheunemann

Werner Hickel

Donald Lupo

Ivan Cabrera

Peter Boldt

Martin Blenkle

Georg Pawlowski

Werner Prass

Olaf Althoff

Andreas Mayer

Compounds of the formula I ##STR1## in which R is a C.sub.1 - to C.sub.22 -alkyl radical,

Substituted thieno�3,2b!thiophenes and their use

A composite membrane comprises a porous carrier membrane (A) and a fluorine-containing permselective layer (C) which is a copolymer and has a thickness of 10 to 500 nm. The copolymer of layer (C) comprises

Composite membranes and processes for their production

An optical component comprises an electromagnetic radiation-transparent polymeric medium having a second-order susceptibility of at least 10.sup.-9 electrostatic units where this polymeric medium comprises compounds having polar-aligned noncentrosymmetric molecular dipoles which have as structural element an electron acceptor which is bound to an electron donor via a conjugated .pi.-electron system, which makes possible an oscillation of the molecular dipole between a ground state having a first dipole moment and an electronically excited state having a second dipole moment different from the first, and the nonionic polymeric medium comprises an alternating arrangement of at least one Langmuir-Blodgett film each of at least two different nonionic polymers having nonlinear optical properties. Besides high mechanical and chemical stability the optical component of the invention has excellent nonlinear optical properties, for example frequency-doubling.

Optical component based on Langmuir-Blodgett layers

Substituted thieno[3,2-b]thiophenes, processes for their preparation and their use Compounds of the formula I ##STR1## in which R is a C.sub.1 - to C.sub.22 -alkyl radical,

Substituted thieno[3,2-b]thiophenes and their use

A layer element comprises a plurality of monomolecular layers in a regular and alternating arrangement ABABAB . . . on a substrate, wherein A is a layer of a dye whose chromophore has a donor-acceptor structure and B is a layer of cellulose whose hydroxyl groups are at least partly substituted by the radical ##STR1## where R.sup.1 and R.sup.2 are each independently of the other an alkyl radical of from 1 to 4 carbon atoms and R.sup.3 is an alkyl radical of from 1 to 18 carbon atoms or phenyl, tolyl or benzyl. It is useful for nonlinear optics.

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Wiesbaden, Germany

Uwe Falk