The synthesis of poly(hydridocarbyne), one of a class of carbon-based random network polymers and a structural isomer of polyacetlyene, is reported. The network backbone of this polymer is primarily composed of tetrahedrally hybridized carbon atoms, each bearing one hydride substituent and linked via three carbon-carbon single bonds into a three-dimensional random network of fused rings. This atomic-level carbon network backbone confers unusual properties on the polymer, including facile thermal decomposition to form diamond or diamond-like carbon high-quality films at atmospheric pressure, by direct deposition or by chemical vapor deposition (CVD), without the use of hydrogen or any other reagent.

A new synthesis of the silicon‐network‐backbone polymer poly(methylsilyne) gives a material that is easily converted by pyrolysis to smooth continous films of stoichiometric silicon carbide (see Figure). The films are adherent to the silicon or alumina substrates, and show root mean square roughness of 169 Å over a 500 μm range. Applications in electronics are envisaged.

Surface-initiated graft polymerization has been shown to be an efficient method for functionalizing solid surfaces for controlled adhesion, lubricity, biocompatibility, and many other purposes. 1 Radical, cationic, anionic, and organometallic-based initiation have all been demonstrated to be successful routes to such surfacegrafted polymer films. 1b-h Surface-bound organometallic ROMP catalysts have been shown to be able to initiate in a "living" manner the polymerization of cyclic olefins with the catalytic site at the end of the growing polymer chain, allowing for possible surface functionalization by selective chain termination, or for possible block copolymerization. 1d This work describes a novel system for initiation of surface-grafted polymerization: the use of lanthanide organometallic catalysts to surface-graft polymer brushes of common, commercially important, noncyclic olefins. These organometallic surface polymerization initiators can also provide the advantages of "living polymerization", block copolymerization of both nonpolar and functionalized monomers, and chemical tailoring of the polymer films' surfaces, for optimized functionality.We have shown previously that homogeneous, robust and uniform silane monolayers can be generated on a variety of oxide surfaces. 2 A layer of 5-hexenylsilane (or any of several vinylterminated silane layers) was generated on a silicon surface by reaction of a 5-hexenyltrichlorosilane precursor with the pretreated surface, as previously described. 2 These functionalized silicon substrates were exposed to a THF solution of (C 10 H 15 ) 2 Sm(THF) 2 3 over a period of 1 to 3 days. It has been shown that, in solution, this complex reduces vinyl groups to form Sm-bound allyls, 4 which are efficient polymerization catalysts for a variety of olefins. 5 The substrates were then removed from the THF solution, rinsed, and placed in an atmosphere of 1200 psi of ethylene. After 12 to 72 h, the substrates were removed from the reaction apparatus, rinsed with methanol, and dried in air.Examination of the silicon surfaces by ATR FTIR spectroscopy and profilometry showed that films of polyethylene had formed on the silicon surfaces, of approximately 90 nm thickness ( Figure 1). The films varied in smoothness, showing average rms roughness of 565 Å over a 2 × 10 6 Å scan range. IR bands at 1098, 1060, and 1016 cm -1 (see inset, Figure 1) demonstrate covalent bonding of the polymer to the silicon surface via Si-O-Si linkages, as well as siloxane network modes. 6 These films could not be removed by application of a pressure-sensitive adhesive, showing strong adhesion to the silicon surface. When a control experiment was performed using a nonfunctionalized silicon substrate, the polyethylene that adsorbed on the silicon surface was completely removed by application of adhesive tape. Better adhesion of polyethylene films to a variety of inorganic substrates has been a topic of intense research; this surfaceinitiated grafting of polyethylene to form robust, strongly attached films may pro...

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