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Full-Text Articles in Chemistry

The Modeling Of Solubility, Frank Christopher Campanell Jan 2006

The Modeling Of Solubility, Frank Christopher Campanell

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In this work the solubilities of gases in liquids and liquids in liquids were modeled using both physical properties and topological descriptors of the solutes. Quantitative structure-activity relationship (QSAR) methods were employed to create single-linear regression (SLR) and multiple-linear regression (MLR) models of the solubilities. Factor analysis was employed to determine the number of significant factors present in the solubilities. The solubilities of monoalcohols in water, halogenated alkanes in water, gases in water, gases in alkanes, and gases in alcohols were examined and modeled.

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Electronic To Vibrational Energy Transfer From Cl* (3 2P1/2) To N2O(Ν1): Failure Of A Simple Kinetic Mechanism, Brian Brumfield Jan 2005

Electronic To Vibrational Energy Transfer From Cl* (3 2P1/2) To N2O(Ν1): Failure Of A Simple Kinetic Mechanism, Brian Brumfield

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Experimental kinetic studies were carried out examining the electronic to vibrational (E-V) energy transfer from spin-orbit excited Cl*(3 2P1/2 , 882 cm-1) to N2O(ν1) (symmetric stretch 1285 cm-1). All studies were carried out in the gas phase at room temperature (298 ± 2 K). Cl* was generated by pulsed laser photolysis of ICl at 532 nm in the presence of various mixtures of N2O, ICl,Ar, and SO2. Time-resolved IR signals of N2O(ν1) fluorescence at 7.8 μm were analyzed to obtain rate coefficients …

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Bismuth Triflate Catalyzed Friedel-Crafts Acylations Of Sydnones, Jennifer Ann Fisher Jan 2005

Bismuth Triflate Catalyzed Friedel-Crafts Acylations Of Sydnones, Jennifer Ann Fisher

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In the present work, suitably functionalized arylsydnones were used to synthesize a variety of 4-acylsydnones and diacyl sydnones, both as potential precursors to novel sydnoquinolines.The approach to the diacyl species is based on the discovery that activated sydnonesbrominate in both the 4 position of the sydnone ring and on the phenyl ring. Thus, it seemed likely that Friedel-Crafts reactions on an activated sydnone would give diacylated species for McMurray coupling to sydnoquinolines. Friedel-Crafts acylations on the 4 position of the sydnone ring have been achieved in high yields using 4 equivalents of various alkyl anhydrides, 25 mol % of bismuth …

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Sonogashira Coupling Routes To Ortho-Alkynl-And- Fused-Ring Sydnones, Andrew John Weisner Jan 2003

Sonogashira Coupling Routes To Ortho-Alkynl-And- Fused-Ring Sydnones, Andrew John Weisner

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In the present work, suitably functionalized arylsydnones were used to synthesize a variety of ortho-alkynyl sydnones both as potential precursors to novel sydnoquinolines and to provide non-linear optical (NLO) species of interest to Wright-Patterson Air Force Base (WPAFB). The versatile intermediate, 3-(2-(trimethylsilylethynyl)phenyl)sydnone, was prepared in good yield by the coupling of 3-(2-iodophenyl)sydnone with trimethylsilyl acetylene under Sonogashira conditions. From this intermediate, several ortho-alkynyl sydnones were prepared via a one-pot desilylation with tetrabutylammonium fluoride and Sonogashira coupling with para-substituted aryl iodides. In addition, a three-reaction-in-one-pot procedure was developed to access some of these species directly from 3-(2- iodophenyl)-sydnone. Subsequent reaction of …

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Selected Synthetic Studies Of Nlo Pi-Bridges And Thermally Stable Monomers, Stacey Marie Fauley Jan 2002

Selected Synthetic Studies Of Nlo Pi-Bridges And Thermally Stable Monomers, Stacey Marie Fauley

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The molecular weights of two series of PEEK polymers were determined using gel permeation chromatography (GPC). The first series contains oxyalkylene linkages. The other series contains oxyethylene linkages. The synthesis of several thermally stable monomers has been investigated. These monomers include 9,9-dihexylfluorene-2,7-dicarboxaldehyde, 2,7-bis(bromomethyl)-9,9- dibutylfluorene and 2,7-bis(hydroxymethyl)-9,9-diethylfluorene. These monomers can be used to form polymers that will contain short conjugated segments separated by nonconjugated segments. The synthesis of 50 g of each of the following monomers was accomplished: bis(3-methylphenyl) phenylphosphine oxide, bis(4-methylphenyl)phenylphosphine oxide, bis(3- carboxyphenyl)phenylphosphine oxide and bis(4-carboxyphenyl)phenylphosphine oxide. These monomers will be used in a polymerization to form polybenzoxazoles. The …

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The Synthesis Of Bromoethoxy And Vinylbenzyloxy Substituted Nlo Chromophores, Michael Joseph Matuszewski Jan 2002

The Synthesis Of Bromoethoxy And Vinylbenzyloxy Substituted Nlo Chromophores, Michael Joseph Matuszewski

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Multiphoton-absorption processes have recently attracted growing interest because of the potential impact on a wide spectrum of applications, ranging from data storage to photodynamic therapy. From the materials standpoint, particular interest is centered in designing chromophores that exhibit a large two-photon cross-section. The current research is focused on establishing synthetic routes that lead to the formation of derivatives of N,N-diphenyl-(7-benzothiazol-2-yl)-9,9-diethyl-9H-fluoren-2-ylamine which contain meta functionalization. A bromoethoxy functionalized chromophore, N-phenyl-N-(3-(2-bromoethoxy)phenyl)-7-(benzothiazol-2-yl)-9,9-diethyl-9H-fluoren- 2-ylamine , was synthesized and used as a polymer pendent while a vinylbenzyloxy chromophore, N-phenyl-N-(3-(4-vinylbenzyloxy)phenyl)-7- (benzothiazol-2-yl)-9,9-diethyl-9H-fluoren-2-ylamine, was synthesized as a hydrosilation substrate. A compound containing three chromophores, 1,3,5-tris(3-(N-phenyl- 4-(7-(benzothiazol-2-yl)-9,9-diethyl-9H-fluoren-2- ylanilino)phenoxymethyl)benzene, has …

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The Functionalization Of Thermally Stable Third-Order Nlo Chromophores, James Richard Sawyer Jan 2001

The Functionalization Of Thermally Stable Third-Order Nlo Chromophores, James Richard Sawyer

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There is a need to functionalize NLO chromophore systems to incorporate them into polymeric matricies by covalent attachment. The functionalization of a series of NLO chromophores based on the N,N-diphenyl-N-[7-(2-benzothiazolyl)-9,9-diethyl-2- fluorenyl ]amine structure has been investigated. All the chromophores were synthesized from the intermediate chromophore N-phenyl-N-[4-(4-bromophenyl)phenyl ]-N-[7-(2- benzothiazolyl)-9,9-diethyl-2-fluorenyl ]amine which was prepared by a six-step process. Bromination of fluorene yielded 2,7-dibromo-fluorene which could be converted to 2,7- dibromo-9,9-diethylfluorene by alkylation with ethyl iodide in DMSO.Reaction of 2,7- dibromo-9,9-diethylfluorene with one equivalent of butyl lithium followed by reaction with DMF provides 2-bromo-7-formyl-9,9-diethylfluorene.Condensation of 2-bromo-7- formyl-9,9-diethylfluorene and 2-aminobenzenethiol in DMSO results in …

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Studies Directed At The Synthesis Of Trialkoxysilyl Substituted Nlo Chromophores, Ida J. Kuhr Jan 2000

Studies Directed At The Synthesis Of Trialkoxysilyl Substituted Nlo Chromophores, Ida J. Kuhr

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The synthesis of trialkoxyalkyl substituted NLO chromophores has been investigated. The chromophore 2-(7-(3-hydroxydiphenylamino)-9,9-diethyl-2-fluorenyl)-benzothiazole was prepared by a five step process. Bromination of fluorene yielded 2,7-dibromo-fluorene which could be converted to 2,7-dibromo-9,9-diethylfluorene by alkylation with ethyl iodide in DMSO.Reaction of 2,7-dibromo-9,9-diethylfluorene with one equivalent of butyl lithium followed by reaction with DMF provides 2-bromo-7-formyl-9,9-diethylfluorene. Condensation of 2-bromo-7-formyl-9,9-diethylfluorene and 2-aminobenzenethiol in DMSO results in the formation of 2-(7-bromo-9,9-diethyl-2-fluorenyl)benzothiazole. The conversion of 3-hydroxydiphenylamine to 3-benzyloxy-diphenylamine was accomplished with benzyl bromide and potassium carbonate in DMF. A palladium catalyzed coupling of 3-benzyloxydiphenylamine and 2-(7-bromo-9,9-diethyl-2-fluorenyl)benzothiazole provided 2-(7-(3-hydroxydiphenyl-amino)-9,9-diethyl-2-fluorenyl)benzothiazole. Several attempts to alkylate 2-(7-(3-hydroxydiphenylamino)-9,9-diethyl-2-fluorenyl)benzothiazole with trimethoxysilylmethyl chloride …

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Synthesis Of Benzoxazoles Containing Allyl Crosslinking Sites Via Claisen Rearrangements, Leslie K. Hutson Jan 1999

Synthesis Of Benzoxazoles Containing Allyl Crosslinking Sites Via Claisen Rearrangements, Leslie K. Hutson

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The reaction of diethyl 2,5-dihydroxyterephthalate with allyl bromide/K2CO3 in DMF followed by hydrolysis provided 2,5-di(allyloxy)terephthalic acid. The conversion of 2,5-di (allyloxy)terephthalic acid to 1,4-di(2-benzoxazolyl)-2,5-di(allyloxy)benzene in PPSE was unsuccessful. However, the reaction of 1,4-di(2-benzoxazolyl)-2,5- dihydroxybenzene with allyl bromide/K2CO3 provided 1,4-di(2-benzoxazolyl)-2,5- di(allyloxy)benzene. DSC analysis indicated that 1,4-di(2-benzoxazolyl)-2,5- di(allyloxy)benzene undergoes a Claisen rearrangement to the corresponding diallyl product. The synthesis of 2-allyloxy-1,4-di(2-benzoxazolyl)benzene was carried out using 2-hydroxy-1,4-di(2-benzoxazolyl)benzene as starting material. DSC analysis was inconclusive with respect to a Claisen rearrangement. The reaction of 2-allyloxybenzoic acid with 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane in PPSE was unsuccessful but the reaction of 2,2-bis(2-(2-hydroxyphenyl)-5-benzoxazolyl)-1,1,1,3,3,3-hexafluoropropane with allyl bromide/K2CO3 in DMF provided 2,2-bis(2-(2- …

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