Abstract: There is disclosed novel colorless ferric di-alkylphosphates of the general formulaFe[OOP(OR).sub.2 ].sub.3.XorFe[OOP(OR).sub.2 ].sub.3in which each R is independently a branched chain alkyl group and X is an anion selected from F.sup.-, PF.sub.6.sup.-, BF.sub.4.sup.-, Ph.sub.4 B.sup.-, CH.sub.3 COO.sup.-, C.sub.2 H.sub.5 COO.sup.-, C.sub.14 H.sub.29 SO.sub.4.sup.-. These compounds react with chelates to give intense and dark colored results and find utility in thermographic materials.

Abstract: A positive-acting thermographic material which is black or dark colored in the unexposed condition turns white or light colored when exposed to elevated temperatures. The material comprises a binder, a dark colored complex of ferric iron with a ligand chosen from organothiophosphorus acids, and a white organophosphorus acid or its alkali or alkaline earth metal salt. At elevated temperatures a double decomposition reaction occurs giving the light colored complex of ferric iron with the organophosphorus acid.

Abstract: Pressure sensitive imaging materials are stable until pressure addressed, but thereafter provide an intense dark image. The materials comprise colorless ferric organophosphate, ferric organophosphinate, or ferric organophosphonate and a colored chelate.

Abstract: A positive-acting thermographic material which is black or dark colored in the unexposed condition turns white or light colored when exposed to elevated temperatures. The material comprises a binder, a dark colored complex of ferric iron with a ligand chosen from organothiophosphorus acids, and a white organophosphorus acid or its alkali or alkaline earth metal salt. At elevated temperatures a double decomposition reaction occurs giving the light colored complex of ferric iron with the organophosphorus acid.

Abstract: Thermographic materials are colorless when unexposed, but provide an intense dark image when thermally addressed. The materials comprise white ferric organophosphate, ferric organophosphinate, or ferric organophosphonate in a clear binder with a colorless catechol or polycatechol held in said binder in solid solution. The choice of substituents on the catechol nucleus can give a change in the color of the thermal image together and provide good near infrared absorption. Use of mixed catechols can give achromatic black images. These combinations of materials show high stability at ambient temperatures.

Abstract: A composite structure and method therefor comprises a metal surface which is coated with a polymer incorporating a bidentate chelating functionality. The polymer provides significant and varied chemical modification to the metal surface and is useful, for example, as a protective coating or a priming layer. Bidentate chelating monomers useful in preparing homopolymers and copolymers with ethylenically-unsaturated non-chelating monomers have structures described by the formula ##STR1## in which R.sup.1 is hydrogen, lower alkyl, chlorinated lower alkyl, CN, or ClP is a connecting linkage of chain length up to to about 75 atoms, andQ is a bidentate chelating group having a high affinity for the ions of the metal of the surface involved.