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Two classes of cyclic tin compounds, trioxa-aza-1-stannabicyclo-[3.3.3]-undecanes, also referred to as stannatranes and tetraaza-1-stannabicyclo-[3.3.3]-undecanes also referred to as azastannatranes are described as are methods for their preparation. These cyclic tin compounds are resistant to rearrangement and the generation of dialkyltin impurities is not observed during the synthesis, purification or deposition of these compounds to form oxostannate films.

A new class of compounds known as chalcogenosilacyclopentanes is described. These compounds are five-membered ring structures containing a silicon-selenium or silicon-tellurium bond, as shown in Formulas (I) and (II). In these compounds, the substituents on the silicon and on the ring carbons may be hydrogen, alkyl, alkoxy, aromatic, or ether groups. The chalcogenosilacyclopentane compounds undergo ring-opening reactions with hydroxyl and other protic functionalities and may be used to prepare substrates that are amenable to thin film deposition techniques such as ALD and CVD.

A method for forming a fluorinated oxostannate film involves vaporizing a volatile fluorinated alkyltin compound having at least two hydrolytically sensitive functional groups or at least two reactive functional groups which are sensitive to oxidation at a temperature greater than 200° C.; providing a substrate; physisorbing or chemisorbing the fluorinated alkyltin compound onto the substrate; and exposing the physisorbed or chemisorbed fluorinated alkyltin compound to a sequence of hydrolysis, irradiation, and/or oxidation steps to form the fluorinated oxostannate thin film on the substrate. Fluorinated alkyltin compounds having formula (I) are also described, in which Rf is a fluorinated or partially fluorinated linear or branched alkyl group having about 1 to about 5 carbon atoms, X is a dialkylamino group having about 1 to about 4 carbon atoms, and n is 1 or 2: (RfCH2)nSnX(4-n) (I)., {"references":["US Pat. 11,459,656B1"]}

Novel N-alkyl substituted perhydridocyclic silazanes, oligomeric N-alkyl perhydridosilazane compounds, and N-alkylaminodihydridohalosilanes, and a method for their synthesis are provided. The novel compounds may be used to form high silicon nitride content films by thermal or plasma induced decomposition. Keywords: Organosilicon; Silicon Nitride; Triisopropylcyclotrisilazane

Materials containing the reaction products of a cyclic azasilane with water and a compound or polymer containing an isocyanate or epoxy functional group and methods for their synthesis are provided. Stable mixtures containing a cyclic azasilane and a compound or polymer containing an isocyanate or epoxy functional group according to invention are stored under anhydrous conditions. The invention also provides a novel class of materials, mono and bis(cycloaza)disiloxanes comprising one or two cyclic structures bridged by an Si--O--Si bond.

A new class of compounds known as chalcogenosilacyclopentanes is described. These compounds are five-membered ring structures containing a silicon-selenium or silicon-tellurium bond, as shown in Formulas (I) and (II). In these compounds, the substituents on the silicon and on the ring carbons may be hydrogen, alkyl, alkoxy, aromatic, or ether groups. The chalcogenosilacyclopentane compounds undergo ring-opening reactions with hydroxyl and other protic functionalities and may be used to prepare substrates that are amenable to thin film deposition techniques such as ALD and CVD.

Thiasilacyclopentane (TSCP) and azasilacyclopentane (ASCP) heteroatom cyclics have proven capable of rapidlyconvertinghydroxylated surfaces to functionalized surfaces ininorganic click reactions. In this work, we demonstrate that the useof thesereagents can be extended to“simultaneous double-clicking”when both inorganic and organic substrates are present atthe onset of the reaction. The simultaneous double-click dependson afirst ring-opening click with an inorganic substrate that iscomplete in∼1 s at 30°C and results in the reveal of a crypticmercaptan or secondary amine group, which can then participatein a second click with an organic substrate. TSCPs and ASCPs cantake part in tandem double-click reactions in which the organicsubstrate is added to the reaction mixture after the initial inorganic click reaction is completed. Additionally, ASCPs with exocyclic functionality, specificallyN-alkenyl-,N-aminoalkyl, andN-alkynyl-ASCPs, are shown to be options for tandem double-clicking in which functionalization proceeds in two independent steps and the sequence of the double-click reaction can be reversed.

Cobalt metallic films are the subject of an ever-expanding academic and industrial interest for incorporation into a multitude of new technological applications. This report reviews the state-of-the art chemistry and deposition techniques for cobalt thin films, highlighting innovations in cobalt metal-organic chemical vapor deposition (MOCVD), plasma and thermal atomic layer deposition (ALD), as well as pulsed MOCVD technologies, and focusing on cobalt source precursors, thin and ultrathin film growth processes, and the resulting effects on film composition, resistivity and other pertinent properties.

Cyclic azasilanes have been synthesized for the purpose of developing coupling agents appropriate for a variety of nanotechnologies including surface modification of nanoparticles, nanocrystals, mesoporous materials and substrates. N-methyl-aza-2,2,4-trimethylsilacyclopentane is representative of this class of compounds. Preliminary data for the treatment of inorganic surfaces, including nanoparticles and oxidized silicon wafers, with cyclic azasilanes suggest high density monolayer deposition by a ring-opening reaction. Cyclic azasilanes contain cryptic amine functionality that can perform a subsequent 'tandem' coupling reaction with functional molecules after the surface triggered ring-opening reaction, allowing for a one-pot self-assembly route on nanostructures. Tandem coupling reactions are demonstrated via addition reactions of the cryptic amine with epoxy and acrylate systems.

Heterocyclic silanes containing Si−N or Si−S bonds in the ring undergo a ring opening reaction with−OH groups at the surface of porous Si nanostructures to generate−SH or−NH functional surfaces, grafted via O−Si bonds. The reaction is substantially faster (0.5−2 h at 25°C) and more efficient than hydrolytic condensation of trialkoxysilanes on similar hydroxy-terminated surfaces, and the reaction retains the open pore structure and photoluminescence of the quantum-confined silicon nanostructures. The chemistry is sufficiently mild to allow trapping of the test protein lysozyme, which retains its enzymatic activity upon release from the modified porous nanostructure.

Hydrophilic N-acylamino acid, N-acyl dipeptide, and N-acyl tripeptide substituted silanes are prepared which can be utilized as reactive surface treatments for particles of pigments, minerals, and fillers. These treated particles form stable dispersions in the aqueous phase of oil-in-water mixtures that are suitable for cosmetic applications. The treated particles may also be used in pressed powder and color cosmetic formulations.

The invention relates to silicon compounds having formula (I): (RfCH.sub.2CH.sub.2).sub.2-n[R(OCH.sub.2CHR').sub.mOR''].sub.nSiX.sub.2 (I). In formula (I), Rf is a linear or branched perfluorinated hydrocarbon having 4 or more carbon atoms, R is a methyl or ethyl group, R' is H or CH.sub.3, m is an integer of 1 to about 24, R'' is a hydrocarbon bridge having 1 to about 11 carbon atoms, n is an integer from 0 to 2, and X is H, Cl or an alkoxy group. The inventive materials may be used to produce siloxanes or silicones by hydrolytic condensation and have utility in surface modification.

Organic trihydridosilanes can be grafted to hydrogen-terminated porous Si nanostructures with no catalyst. The reaction proceeds efficiently at 80 °C, and it shows little sensitivity to air or water impurities. The modified surfaces are stable to corrosive aqueous solutions and common organic solvents. Octadecylsilane H3 Si(CH2 )17 CH3 , and functional silanes H3 Si(CH2 )11 Br, H3 Si(CH2 )9 CH=CH2 , and H3 Si(CH2 )2 (CF2 )5 CF3 are readily grafted. When performed on a mesoporous Si wafer, the perfluoro reagent yields a superhydrophobic surface (contact angle 151°). The bromo-derivative is converted to azide, amine, or alkyne functional surfaces via standard transformations, and the utility of the method is demonstrated by loading of the antibiotic ciprofloxaxin (35 % by mass). When intrinsically photoluminescent porous Si films or nanoparticles are used, photoluminescence is retained in the grafted products, indicating that the chemistry does not introduce substantial nonradiative surface traps.

Dipodal silanes possess two silicon atoms that can covalently bond to a surface. They offer a distinctive advantage over conventional silanes in terms of maintaining the integrity of surface coatings, adhesive primers and composites in aqueous and aggressive environments. The improved durability of such dipodal silanes is associated with an increased crosslink density of the interphase and the inherent resistance to hydrolysis, as they can form six, rather than three, Si-O bonds to the substrate. This study examines dipodal silanes with hydrophobic alkyl functionality and compares them with similar functionality on conventional silane coupling agents. It also introduces new structural dipodal silanes containing pendant and bridged functionality and then examines their stability in aqueous environments. In strongly acidic and brine environments, dipodal silanes clearly demonstrate improved resistance to hydrolysis compared to conventional silane coupling agents.

Four different synthetic methods for preparation of aromatic silanes have been developed and the hydrosilylation route has been proved to be one as the most commercially significant. A series of specialty aryl silanes have been synthesized for the potential applications of high performance and high temperature as silane coupling agents. The thermal stabilities of the bridged aromatic silanes have been examined using thermal gravimetric analysis (TGA) and compared against the gamma-substituted alkylsilanes and phenyltrimethoxysilane. These materials have greater thermal stability than the gamma-substituted, but marginally lower than phenyltrimethoxysilane.

The interaction of hydridosilanes with oxide-free metal substrates was evaluated in order to determine their potential for surface modification analogous to alkoxysilanes with metal oxide substrates. Under mild condi- tions, trihydridosilanes interact with a variety of clean, hydrogenated and fresh metal and metalloid surfaces, including titanium, silicon and gold. In contrast, monohydridosilanes appear to have minimal interaction. All classes of hydridosilanes have minimal interaction with anhydrous oxide surfaces. Preliminary results suggest that surface modification with trihydridosilanes may provide a route for generating self-assembled monolayers on metal substrates. The synthesis of new trihydridosilanes is described. Contact angle, FTIR and XPS data for modified surfaces are provided.

Triethoxysilanes having hydrophilic R’ groups (PEG(6-9), carboxyl, aminopropyl, and acetylhydroxyprolyl) were synthesized and studied as surface treatments to improve pigment wetting and dispersion in water-based color cosmetics.