Abstract: Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

Abstract: Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

Abstract: High molecular weight polysilanes are prepared using highly non-chain-transferring solvents. Certain alloys of sodium can also be used to advantage with such solvents. The high molecular weights are achievable even in the commercially preferred "normal" addition procedure.

Abstract: A method of controlling the yield of polysilane of a desired molecular weight and/or polydispersity prepared in a reductive condensation of corresponding silane monomers on a solid catalyst dispersed in an inert solvent for both the monomers and the growing polymer chains, comprises determining the variation of molecular weight and/or polydispersity of the polysilane as a function of the solubility of the polysilane in reaction solvent, determining thereby a chosen optimum solubility of the polysilane in solvent for obtaining a desired yield of polysilane of said desired molecular weight and/or polydispersity, and thereafter carrying out the preparation of the polysilane in a solvent in which the polysilane has said chosen optimum solubility.

Abstract: Polymerization of acetylenic monomers is achieved by using a catalyst which is the reaction product of a tungsten compound and a reducing agent effective to reduce W(VI) to W(III and/or IV), e.g., WCl.sub.6.(organo-Li, organo-Mg or polysilane). The resultant silylated polymers are of heretofore unachievable high molecular weight and can be used as precursors to a wide variety of new acetylenic polymers by application of substitution reactions.

Abstract: Poly(silyl silanes) have been prepared. They have high photosensitivity and excellent resistance to oxygen-reactive ion etching processes. They are useful as photodepolymerizable photoresists, barrier layers, etc.

Abstract: Polymerization of acetylenic monomers is achieved by using a catalyst which is the reaction product of a tungsten compound and a reducing agent effective to reduce W(VI) to W(III) and/or IV), e.g., WCl.sub.6.(organo-Li, organo-Mg or polysilane). The resultant silylated polymers are of heretofore unachievable high molecular weight and can be used as precursors to a wide variety of new acetylenic polymers by application of substitution reactions.

Abstract: Polysilane polymers in which the Si backbone is interrupted by atoms such as O, Ge, Sn, P, etc., are useful photoresists especially in the solvent development mode.

Abstract: New polysilane copolymers comprise recurring units of --Si(X)(Y)-- and Si(A)(B)--, Si(X)(Y) being different from Si(A)(B),whereinX and Y together have 1-13 carbon atoms, and X and Y each independently is hydrogen, alkyl, cycloalkyl, phenyl, alkylphenyl, or phenylalkyl, with the proviso that only one of X and Y contains a phenyl moiety, or together X and Y are an alkylene group forming a ring with the adjoining Si atom,and whereinA and B together have 3-13 carbon atoms, and A and B each independently is alkyl or cycloalkyl, with the proviso (a) that when one of A and B is ethyl, the other is not methyl or ethyl, and (b) that when one of A and B is n-propyl and the other is methyl, X and Y are not both methyl.Corresponding homopolysilanes are also provided.Upon ultraviolet irradiation, they photodepolymerize to form volatile products. As a result, they represent a new class of photoresists which enable direct formation of a positive image eliminating the heretofore required development step.

Abstract: New polysilane copolymers comprise recurring units of --Si(X)(Y)-- and Si(A)(B)--, Si(X)(Y) being different from Si(A)(B), whereinX and Y together have 1-13 carbon atoms, and X and Y each independently is hydrogen, alkyl, cycloalkyl, phenyl, alkylphenyl, or phenylalkyl, with the proviso that only one of X and Y contains a phenyl moiety, or together X and Y are an alkylene group forming a ring with the adjoining Si atom, and whereinA and B together have 3-13 carbon atoms, and A and B each independently is alkyl or cycloalkyl, with the proviso (a) that when one of A and B is ethyl, the other is not methyl or ethyl, and (b) that when one of A ad B is n-propyl and the other is methyl, X and Y are not both methyl.Corresponding homopolysilanes are also provided.Upon ultraviolet irradiation, they photodepolymerize to form volatile products. As a result, they represent a new class of photoresists which enable direct formation of a positive image eliminating the heretofore required development step.