Trapping reactions, matrix isolation and kinetics of a few photogenerated silylenes and silenes have been studied. Several vinylsiliranes, the long sought intermediates from the addition of dimesitylsilylene to various 1,3-dienes, have been made and characterized. The product study by various nmr techniques demonstrates that the silylene addition to the dienes is highly stereospecific and the addition to the cis v bond is about 9 times faster than to the trans one in gis,trans-2,4-hexadiene. High stereospecifity of the addition of dimesitylsilylene to cis and trans-2-pentenes and to cis and trans-4-octenes has also been found. The reinvestigation of dimesitylsilylene to cis and t;rans-2-butene affords the possible explanation for the confusing results and wrong conclusion from the earlier report by Ando and coworkers.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xx, 456 p.; also includes graphics Includes bibliographical references (p. 449-456). Available online via OhioLINK's ETD Center

The incorporation of fluorine into SiO2 has been shown to reduce the dielectric constant of the existing materials by reducing the electrical polarizability. However, the incorporation of fluorine has also been shown to decrease film stability. Therefore, new efforts have been made to find different ways to further decrease the relative dielectric constant value of the existing low-k materials. One way to reduce the dielectric constant is by decreasing its density. This reduces the amount of polarizable materials. A good approach is increasing porosity of the film. Recently, fluorinated silica xerogel films have been identified as potential candidates for applications such as interlayer dielectric materials in CMOS technology. In addition to their low dielectric constants, these films present properties such as low refractive indices, low thermal conductivities, and high surface areas. Another approach to lower k is incorporating lighter atoms such as hydrogen or carbon. Silsesquioxane based materials are among them. However, additional integration issues such as damage to these materials caused by plasma etch, plasma ash, and wet etch processes are yet to be overcome. This dissertation reports the effects of triethoxyfluorosilane-based (TEFS) xerogel films when reacted with silylation agents. TEFS films were employed because they form robust silica networks and exhibit low dielectric constants. However, these films readily absorb moisture. Employing silylation reactions enhances film hydrophobicity and permits possible introduction of this film as an interlayer dielectric material. Also, this work describes the effects of SC-CO2 in combination with silylating agents used to functionalize the damaged surface of the ash-damaged MSQ films. Ashed MSQ films exhibit increased water adsorption and dielectric constants due to the carbon depletion and modification of the properties of the low-k material caused by interaction with plasma species. CO2 is widely used as a supercritical solvent, because of its easily accessible critical point, low cost, and non-hazardous nature. Its unique diffusion and surface tension properties make SC-CO2 a good candidate for treatment of porous ultra low-k materials.

No description available.

Thesis advisor: Kian L. Tan / The acceleration of catalytic asymmetric silylation of syn-diols and triols by use of an azole additive has been developed. By simply adding 7.5-20 mol % of a commercially available small-molecule, 5-ethylthiotetrazole, to a previously reported chiral catalyst, reactions proceed within one hour delivering the desired products with similarly high yields and enantiomeric ratios; there is minimal reaction during the same period when one of the co-catalysts is absent. In an attempt to better understand this silylation mechanism, computational catalyst design and synthetic development were employed. / Thesis (MS) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: Marc L. Snapper / Chapter 1: Brief overview of the catalytic enantioselective functionalization and kinetic resolution of alcohols Chapter 2: Kinetic resolution of syn-diols by catalytic enantioselective sulfonylation Chapter 3: Significant improvement on catalytic enantioselective silylation of syn-diols and triols through the use of a tetrazole additive / Thesis (MS) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

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Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: C. Grant Willson. Vita. Includes bibliographical references.

Thesis advisor: Kian L. Tan / Thesis advisor: James P. Morken / Described herein are four different research projects spanning over two different research groups. The first two projects describe the development and application of scaffolding catalysts for the (1) site-selective silylation of ribonucleosides and (2) the distal and diastereoselective hydroformylation of homoallylic alcohols. These projects emphasize the effectiveness of scaffolding catalysts to bind a hydroxyl-containing substrate and control the site- or regioselectivity of a reaction using said substrate. The third project describes a hydroxyl-directed diboration of homoallylic and bis-homoallylic alcohols. The hydroxyl-containing 1,2-bis(boronates) are valuable intermediates for further synthetic manipulations. One such manipulation, a hydroxyl-directed Suzuki cross-coupling reaction, is the focus of the final project. This directed cross-coupling reaction forges carbon-carbon bonds in a stereoselective manner, highlighted in the total synthesis of the naturally occurring compound, debromohamigeran E. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 208-216). Available also in a digital version from Dissertation Abstracts.