Abstract: Nonlinear optic chromophores comprising stabilized radical structures, mixtures thereof, methods for their production, nonlinear optical materials containing such chromophores, and the use of such materials in electro-optic, solar conversion, photovoltaic and all-optical nonlinear devices are described.

Abstract: A novel solventless process is described for the preparation of imidazole-2-thiones. The new solventless process tolerates a variety of bases as co-reactants which introduces feedstock flexibility into the process while the solventless feature renders the process more environmentally friendly by eliminating volatile organic solvents from the process, reducing energy consumption (associated with solvent recovery and/or recycling), and allows shorter reaction time and workup. Furthermore, the elimination of solvents enhances workplace safety by obviating the need for flammable and/or toxic solvents.

Abstract: Imidazoles may be manufactured by reacting a glyoxal, ammonia, an aldehyde, and optionally a primary amine, in the presence of a Bronsted acid whose pKa is approximately equal to the pKa of the ammonium cation of the primary amine, or if the primary amine is not present, to the pKa of the ammonium (NH4+) cation. The reaction may be used to make in relatively high yields a wide variety of imidazoles using relatively inexpensive starting materials. The imidazoles are useful as chemical intermediates.

Abstract: This invention concerns cyclic aromatic amide oligomer compositions and a process for preparing such cyclic oligomers.

Abstract: A strengthened polyimide film is described, which has improved adhesion when bonded to a metal foil through a heat-resistant adhesive, containing from 0.02 to 1% by weight, based on the weight of the film, of an organo-metallic compound wherein the metal is tin, bismuth or antimony. A process for preparing a strengthened polyimide film is also described wherein an organometallic compound is introduced into a film-forming polyamic acid polymer prior to the casting step.

Abstract: A process for the production of glyoxylic acid by reacting glycolic acid and oxygen in an aqueous solution at pH 7-10 in the presence of the enzyme glycolate oxidase and a non-enzymatic catalyst for the decomposition of hydrogen peroxide, and an amine buffer capable of forming a chemical adduct with glyoxylic acid.

Abstract: An environmentally innocuous effective replacement for thiourea is disclosed for use as a complexing agent in displacement plating processes in which the plating solution is applied to the substrate surface to be plated by immersion or by spraying, cascading, pouring and the like. The replacement complexing agent is an imidazole-2-thione compound having the formula: ##STR1## wherein A and B are the same or different --R--Y groups, wherein R is linear, branched or cyclic alkenyl group containing 1 to 12 carbon atoms and Y is a hydrogen, halogen, cyano, vinyl, phenyl, or ether moiety. Of this class of compounds, 1-methyl-3-propyl-imidazole-2-thione is preferred for immersion tin plating. This class of complexing agents is particularly useful in spray displacement tin plating for the manufacture of printed circuit boards wherein free tin metal is added to the plating solution.

Abstract: A process for the preparation of 1,3-disubstituted imidazolium salts that comprises reaction of an .alpha.-dicarbonyl compound, an aldehyde, an amine and an acid is disclosed.

Abstract: The present invention discloses 1,3-dialkylimidazole-2-thiones catalysts for epoxy/anhydride reactions (and other reactions) and a method of making these catalysts. Epoxy/anhydride coatings containing these improved catalysts offer the following advantages: improved appearance (especially since even weeks after application the coatings still have a "wet" look); better pot-life; improved resistance to alkaline substances which will improve durability; improved solubility; and coatings which have a reduced volatile organic content (VOC).

Abstract: The present invention discloses 1,3-dialkylimidazole-2-thiones catalysts for epoxy/anhydride reactions (and other reactions) and a method of making these catalysts. Epoxy/anhydride coatings containing these improved catalysts offer the following advantages: improved appearance (especially since even weeks after application the coatings still have a "wet" look); better pot-life; improved resistance to alkaline substances which will improve durability; improved solubility; and coatings which have a reduced volatile organic content (VOC).

Abstract: The present invention describes the use of 1,3-dialkylimidazole-2-thiones as a catalyst for epoxy/anhydride reactions (and other reactions) and a method of making these catalysts. Epoxy/anhydride coatings containing these improved catalysts offer the following advantages: improved appearance (especially since even weeks after application the coatings still have a "wet" look); better pot-life; improved resistance to alkaline substances which will improve durability; improved solubility; and coatings which have a reduced volatile organic content (VOC).

Abstract: A process for the preparation of 1,3-disubstituted imidazolium salts that comprises reaction of an .alpha.-dicarbonyl compound, an aldehyde, an amine and an acid is disclosed.