Nitrosoarenes: magnetic anisotropy, donor-acceptor bonding and host-guest chemistry

dc.contributorShaughnessy, Kevin H.
dc.contributorJennings, Michael P.
dc.contributorPapish, Elizabeth T.
dc.contributorPigza, Julie A.
dc.contributor.advisorBlackstock, Silas C.
dc.contributor.authorKelley, Sarah Ariel
dc.contributor.otherUniversity of Alabama Tuscaloosa
dc.descriptionElectronic Thesis or Dissertationen_US
dc.description.abstractNitrosoarenes (Ar-N=O) were first reported by Baeyer in 1874 after successful synthesis of nitrosobenzene via a diphenyl mercury reaction with nitrosyl bromide. C-nitroso compounds (R-N=O), like nitrosobenzene, fall between hydroxylamines (R-NH-OH) and nitro compounds (R-NO2) on the amine oxidation scale making them common intermediates for many synthetic amine oxidation reactions. Nitrosobenzenes exhibit a number of unique properties, which stem from their structure. A small energy gap between the HOMO (n*) and LUMO (?*) orbitals of the N=O function allows for several unique chemical and spectroscopic properties of nitrosoarenes. Nitrosobenzene and its derivatives have a blue-green color in monomeric form and reversibly dimerize to a colorless form in the solid state, thus yielding a dynamic covalent bonding reaction for this class of compounds. One area of our studies focuses on the very large (2-3 ppm) magnetic anisotropy of the nitroso group, which is evaluated for a series of ortho-substituted nitrosoarenes. The nitroso (-N=O) functions of these molecules are sterically forced into a primary (majority) orientation in the molecule by the ortho substituent, thereby allowing the NMR analysis of the magnetic environment around an oriented -N=O group at room temperature. Multiple substrates have been synthesized, including oriented 1,3-(bis)nitroso compounds, which have double the amount of shielding of the “syn” proton. A series of NMR techniques is employed to prove the NMR signal assignments for these compounds including: 1H, 13C, NOE, COSY, HSQC, and HMBC NMR spectroscopy. Also studied is the electron donor-acceptor (DA) bonding ability of the N=O group of N,N-dimethyl-4-nitrosobenzene (DMANB) and N,N-diethyl-4-nitrosobenzene (DEANB), in the monomeric state, as they complex and co-crystallize with electron-poor alkenes such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tetracyanoethylene (TCNE). Finally, encapsulation of N,N-dimethyl-4-nitrosobenzene (DMANB) and p-nitrosocumene (p-NC) by organic host molecules such as octa-acid (OA), cucurbit[7]uril (CB7), and cyclodextrins (?,?,?-cd) in aqueous solution is studied.en_US
dc.format.extent396 p.
dc.publisherUniversity of Alabama Libraries
dc.relation.hasversionborn digital
dc.relation.ispartofThe University of Alabama Electronic Theses and Dissertations
dc.relation.ispartofThe University of Alabama Libraries Digital Collections
dc.rightsAll rights reserved by the author unless otherwise indicated.en_US
dc.titleNitrosoarenes: magnetic anisotropy, donor-acceptor bonding and host-guest chemistryen_US
dc.typetext of Alabama. Department of Chemistry and Biochemistry University of Alabama
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
80.6 MB
Adobe Portable Document Format