Joshua R. Smith

Cross‐Hyperconjugation: An Unexplored Orbital Interaction between π‐Conjugated and Saturated Molecular Segments

Crossing a barrier: Molecules with saturated ER2 units (E=C or Si, R=electron-releasing group) inserted between two π-conjugated segments have electronic and optical properties that resemble those ...

Preparation of Covalent Long-Chain Trialkylstannyl and Trialkylsilyl Salts and an Examination of their Adsorption on Gold

We report the attachment of alkyl residues to a gold surface through a tin atom. Covalent trialkylstannyl and trialkylsilyl salts of trifluoromethanesulfonic, trifluoroacetic, and p-toluenesulfonic acids containing one to three C(18)H(37) chains and two to no CH(3) groups in the molecule have been synthesized. They were tested for adsorption on gold from solution under ambient conditions using ellipsometry, FTIR spectroscopy, contact angle, and electrode-blocking measurements. All nine trialkylstannyl salts form similar stable monolayers with the loss of the acid residue and form no multilayers. The monolayers differ from those formed from alkanethiols. They are much thinner, less ordered, less hydrophobic, and only slightly electrode-blocking. Their stability to solvents, bases, acids, and reductants is somewhat lower than that of a 1-octadecanethiol monolayer, but their resistance to heat and oxidants, including air, is slightly better. The distinctive properties of these monolayers may be of interest in certain circumstances, but we expect the attachment of molecules to gold through a tin atom to be of the most value in work with single-molecule structures. The trialkylsilyl salts showed no tendency to adsorb onto gold under these conditions.

Indole and 3-chloroindole: The source of the disagreeable odor of Hygrophorus paupertinus

The odor emanating from sporocarps of Hygrophorus paupertinus is disagreeable and fecal-like. Solid phase microextraction (SPME) and analysis by gas chromatography-mass spectrometry (GC-MS) showed 1-octen-3-ol, indole and 3-chloroindole were responsible for the odor. This is the first case in which 3-chloroindole has been identified from a terrestrial organism.

Synthetic approaches to a fluorinated tetrahedrane

Abstract Approaches to tetrakis(2-chlorotetrafluoroethyl)tetrahedrane ( 2 ) from 1,6-dichlorooctafluoro-3-hexyne ( 4 ) have been explored. The synthesis and chemistry are described of cyclopropenyl ketenimines ( 6a , b ), a Dewar thiophene ( 24 ) and a cyclobutadienetricarbonyliron complex ( 33 ) derived from this acetylene.

Synthesis and properties of the strained alkene perfluorobicyclo[2.2.0]hex-1(4)-ene.

The title fluoroalkene has been generated by dehalogenation of dibromide and diiodide precursors and trapped in situ. retro-Diels-Alder reaction of its adduct with N-benzylpyrrole has made the alkene available in high yield and purity. In sharp contrast to its extremely labile hydrocarbon counterpart, the fluoroalkene is very stable yet highly reactive. Its characterization includes its electron affinity, photoelectron spectrum, and the previously reported structure determination by electron diffraction.

Highly fluorinated sulfonium enolates

Abstract A sulfonium enolate (5) was formed upon heating 1,6-dichlorooctafluorohex-3-yne (2) in dimethyl sulfoxide. This crystalline ylid exists in solution as a solvent-polarity-dependent mixture of cis and trans stereoisomers that displays dynamic behavior on the NMR timescale. The compound is easily hydrolyzed to a stable sulfonium β-diketonate (6).