Self-Assembled Monolayers As Models For Silica
| dc.contributor.author | Cavadas, Francisco T. | en |
| dc.contributor.committeechair | Deck, Paul A. | en |
| dc.contributor.committeecochair | Anderson, Mark R. | en |
| dc.contributor.committeemember | Hanson, Brian E. | en |
| dc.contributor.department | Chemistry | en |
| dc.date.accessioned | 2014-03-14T20:33:18Z | en |
| dc.date.adate | 2002-04-18 | en |
| dc.date.available | 2014-03-14T20:33:18Z | en |
| dc.date.issued | 2001-08-15 | en |
| dc.date.rdate | 2012-06-22 | en |
| dc.date.sdate | 2002-04-10 | en |
| dc.description.abstract | The reaction of hydroquinone and 1,12-dibromododecane affords 4-(12-bromo-dodecyloxy)phenol (4, 7% yield). The alkyl bromide (4) was converted to the corresponding thiol with thiourea to afford 4-(12-mercaptododecyloxy)phenol (1) in 52% yield. The reaction of t-butyllithium with 4-bromoanisole followed by reaction with 1-12-dibromododecane affords a mixture of 4-bromoanisole, 1,12-dibromododecane ,and 4-(12-bromododecyl)-anisole (6). Silica gel chromatography resulted in an inseperable mixture of 4-bromoanisole and (6). Reaction of the mixture with BBr3 afforded 4-(12-bromododecyl)phenol (7) in 34% yield. The alkyl bromide (7) was converted to the corresponding thiol with thiourea to afford 4-(12-mercaptododecyl)phenol (2) in 9% yield. Reduction of 16-mercaptohexadecanoic acid with BH3â hTHF afforded 16-mercaptohexadecanol (3) in 53% yield. All new compounds were characterized by ¹H NMR, ¹³C NMR, transmission IR, HRMS, and, where possible, elemental microanalysis. Self-assembled monolayers (SAMs) on gold were prepared using thiols 1, 2, and 3. SAMs were characterized using reflectance-absorbance infrared spectroscopy (RAIRS). Diagnostic vibrational modes were assigned by comparing RAIRS spectra to normal mode frequencies and intensities calculated using DFT methods at the 6-31G* level using commercial software. Water droplet goiniometry found contact angles of 52o, 53o, and 64o for SAMs prepared from 1, 2, and 3, respectively. SAMs of 1 and 2 were found to be hydrophilic. When SAMs prepared from 1, 2, and 3 were silylated with phenyldimethylchlorosilane, the resulting contact angles were 78o, 74o, and 75o respectively. A significant increase in contact angles for silylated SAMs of 1 and 2 indicated facile silanization of the surface hydroxides. RAIRS spectra were also obtained for the functionalized SAMs. Silylated SAMs prepared from 1, 2, and 3 are currently under investigation as models for silica-immobilized metallocene olefin polymerization catalysts. | en |
| dc.description.degree | Master of Science | en |
| dc.identifier.other | etd-04102002-103407 | en |
| dc.identifier.sourceurl | http://scholar.lib.vt.edu/theses/available/etd-04102002-103407/ | en |
| dc.identifier.uri | http://hdl.handle.net/10919/31671 | en |
| dc.publisher | Virginia Tech | en |
| dc.relation.haspart | Mastersthesis2.pdf | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject | silica | en |
| dc.subject | Self-Assembled monolayers | en |
| dc.title | Self-Assembled Monolayers As Models For Silica | en |
| dc.type | Thesis | en |
| thesis.degree.discipline | Chemistry | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | masters | en |
| thesis.degree.name | Master of Science | en |
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