Abstract: Osmium complexes having the formula [Os(II) (N—N)2L—L]2+ 2A? (or A2?), or [Os(II) N—N(L—L)2]2+ 2A? (or A2?), where N—N is a bipyridine or phenanthroline ligand, L—L is a ?-acid bidentate ligand, and A is counter ion.

Abstract: The present invention provides, as heteroaromatic compounds made functional so as to be used for nonlinear optical materials, compounds represented by the following general formula (1), and also provides polymers obtained from these and nonlinear optical parts comprising such polymers. In the formula, Ar.sup.1 and Ar.sup.2 each represents a divalent aromatic group; R.sup.1, R.sup.2 and R.sup.3 each represents an atom or a group independently selected from a hydrogen atom or an alkyl group and an aromatic group; X.sup.1 represents a monovalent organic group; n represents an integer of 2 to 12; and Z.sup.1 and Z.sup.2 each represents a group independently selected from electron attractive functional groups.

Abstract: As a heteroaromatic compound made functional so as to be used in nonlinear optical materials, the present invention provides a heteroaromatic compound represented by the following Formula (1), (2), (3) or (4), a polymer obtained from any of these, a nonlinear optical element comprised of the polymer, an optical device having such an element, and a process for producing them. ##STR1## wherein Ar.sup.1, Ar.sup.2 and Ar.sup.3 each independently represent an aromatic group or an aromatic group having a substituent, R.sup.1, R.sup.2 and R.sup.3 each independently represent a hydrogen atom or a monovalent organic group, X represents a monovalent organic group, Y represents a hydrogen atom or a monovalent functional group, and n represents an integer of 2 to 10.

Abstract: A process for intramolecularly condensing a polyamic acid composition containing an NLO compound to form a polyimide host matrix composition containing as a guest the NLO compound, which process includes the step of uniformly heating the polyamic acid composition, in the absence of a solvent or diluent, to a temperature at which the intramolecular condensation will occur without thermal degradation of the NLO compound, so that the temperature differential within the polyamic acid is below that which will produce localized thermal degradation temperatures, until the intramolecular condensation of the polyamic acid composition to the polyimide host matrix composition is substantially complete. Polyimide host matrix compositions containing guest NLO compounds prepared by the inventive process are also disclosed, wherein the NLO compounds have external field-induced molecular alignments.

Abstract: Nonlinear optical compounds which contain a heteroaromatic ring and may further comprise a tricyanovinyl group attached to the heteroaromatic ring.

Abstract: A method for forming a polyamic acid having nonlinear optical (NLO) or pre-NLO side chains, which method includes the steps of:(1) providing a bis-(aromatic dicarboxylic acid anhydride) containing at least one NLO or pre-NLO side chain having the structure represented by:D-R-Awherein D, R and A form a delocalized resonance configuration in which R is a pi-conjugated non-centrosymmetric moiety, A is hydrogen or an electron withdrawing moiety and D is an electron donating moiety covalently linked to the bis-(aromatic dicarboxylic acid anhydride); and(2) reacting the bis-(aromatic dicarboxylic acid anhydride) with an aromatic diamine to form a polyamic acid having NLO or pre-NLO side chains. Methods for preparing polyamic acids having NLO or pre-NLO side chains by reacting aromatic diamines having NLO or pre-NLO side chains with bis-(aromatic dicarboxylic acid anhydrides) are also disclosed. Methods of forming the polyamic acids into polyimides having NLO side chains are also included.

Abstract: A composition exhibiting a second order nonlinear optical properties containing a non-centrosymmetric aromatic nonlinear optical compound possessing a delocalized resonance configuration as a guest in a host polyquinoline polymer matrix.