Preparation,Reactions, and NMR Studies of 4-Methyl-4-Phospha-Tetracyclo [3.3.0.02,8.03,8] Octane 4-Oxide and Derivatives

Abstract

The title compound which we¹ and others² have previously synthesized has now been extensively investigated. The tetracyclic phosphonium chloride 1 was prepared by treatment of norbornadiene with CH₃PCl₂ at 65–80°C for one week. Treatment of 1 with AICl₃/CH₂CI₂ gave 2. Direct or “Inverse” addition at water to 2 dictated the stereochemistry of the oxide 3. Stereoassignments of 3 were made based on lanthanide shift ?¹H and ¹³C nmr studies studies. Extensive 2-D nmr studies (HETCOR, COSY) and triple irradiation experiments enabled chemical shift and coupling constant assignments.     

Controllable thermal degradation of 2,4,6-trinitrotoluene (TNT) by absorption and confinement into mixed metal sponges

In this work, we report the absorption and confinement of 2,4,6-trinitrotoluene (TNT) in porous metals (Ag, Ag/Al, and Ag/Cu), and the effect of the physical properties of the metal on the calorimetric properties of TNT using thermogravimetric analysis and differential scanning calorimetry. The surface area and pore size distribution of the confiners were calculated to determine their effect on both the onset temperature and the rate at which TNT volatilizes. Confinement of TNT into the mixed metal sponges was confirmed by scanning electron microscopy. Overall, this study provides an insight into the fundamental factors influencing the properties of energetic materials under confinement that could potentially allow for more controlled and reliable degradation techniques depending on the characteristics of the porous material.     

An Electrochemical Immunobiosensor for Direct Detection of Veterinary Drug Residues in Undiluted Complex Matrices

An electrochemical immunobiosensor is developed that allows the detection of small molecules, such as drugs, in undiluted complex samples, with no washing or rinsing steps via a displacement assay. This is achieved using an interface comprised of a mixed layer of oligo(phenylethynylene) molecular wire (MW), to allow electrochemical communication, and oligo(ethylene glycol) (OEG) to control the interaction of proteins and electroactive interferences with the electrode surface. The mixed layer is formed from in situ‐generated aryl diazonium cations. To the distal end of the MW, a redox probe 1,1′‐di(aminomethyl)ferrocene (FDMA) is attached followed by an epitope (the structural feature the antibody selectively recognizes) to which an antibody would bind. Association or dissociation of the antibody with the sensing interface causes a modulation of the ferrocene electrochemistry. Antibody complexed electrodes are exposed to samples containing spiked enrofloxacin (unbound target analyte), in milk and environmental water and interrogated using square wave voltammetry (SWV). The lowest detected concentration of free enrofloxacin was 10 pg mL^?1 in phosphate buffer, 50 mM, pH 7. For free enrofloxacin detection in undiluted complex matrices, by adding disodium EDTA (50 mM), the recovery obtained was 94.1 % in skim milk and 88.5 % in stream water, respectively as compared to clean phosphate buffer. The immunobiosensor response time was 10–15 minutes. The sensor performance in milk was shown to be superior to a standard method based on Liquid Chromatography Mass Spectroscopy (LC‐MS/MS).