Jack M. Miller

The introduction of SCF3 into aromatic substrates using CuSCF3 and alumina-supported CuSCF3

Abstract Trifluoromethylthiocopper(I) has been readily prepared from the silver analogue, using a metathetical reaction with copper(I) bromide. Homogeneous CuSCF 3 and the supported reagent CuSCF 3 -alumina have been compared in their reactivity towards aryl iodides, in order to form trifluoromethylaryl sulphides in good yields.

19F mas NMR and FTIR analysis of the adsorption of alkali metal fluorides onto alumina

Abstract NaF, KF, RbF and CsF have been adsorbed onto alumina and the resulting reagents have been analysed by IR and 19 F magic-angle spinning NMR spectroscopy. The results show that MF reacts with the alumina surface to form AlF 6 3− , and CO 3 2− is formed as a byproduct due to the adsorption and reaction of atmospheric CO 2 .

Hydrogen bonding in organic synthesis. Part 6. C-Alkylation of β-dicarbonyl compounds using tetra-alkylammonium fluorides

Mono-C-alkylation of a number of β-dicarbonyl compounds using alkyl iodides and tetra-alkylammonium fluorides is described. Yields are high with primary iodides and isopropyl iodide, but much lower with s-butyl and t-butyl iodides. The reactions occur under mild conditions with no apparent O-alkylation or other competing reactions.

Prospects for doubling the range of Advanced LIGO

In the coming years, the gravitational wave community will be optimizing detector performance for a variety of astrophysical sources that make competing demands on the detector sensitivity in different frequency bands. In this paper we describe a number of technologies that are being developed as anticipated upgrades to the Advanced LIGO detector, and quantify the potential sensitivity improvement they offer. Specifically, we consider squeezed light injection for reduction of quantum noise, detector design and materials changes which reduce thermal noise, and mirrors with significantly increased mass. We explore how each of these technologies impacts the detection of the most promising gravitational wave sources, and suggest an effective progression of upgrades which culminate in a factor of two broadband sensitivity improvement.

V2O5 catalysts supported on Al2O3–SiO2 mixed oxide: 51V, 1H MAS solid-state NMR, DRIFTS and methanol oxidation studies

Abstract Alumina–silica mixed oxide, synthesized by the sol–gel technique, was used as a support for dispersing and stabilizing the active vanadia phase. The catalysts were characterized employing 51 V and 1 H solid-state MAS NMR, diffuse reflectance FT-IR, BET surface area measurements. The partial oxidation activities of the catalysts were tested using methanol oxidation as a model reaction. 51 V solid-state NMR studies on the calcined catalysts showed the peaks corresponding to the presence of both tetrahedral and distorted octahedral vanadia species at low vanadia loadings and with an increase in V 2 O 5 content, the 51 V chemical shifts corresponding to amorphous V 2 O 5 like phases were observed. DRIFTS studies of the catalysts indicated the vibrations corresponding tetrahedral vanadia species at low and medium loadings and at high V 2 O 5 contents the vibrations corresponding VO bonds of V 2 O 5 agglomerates were observed. The V/Al–Si catalysts exhibited high selectivity for the dehydration product dimethyl ether in the methanol partial oxidation studies showing the predominance of the acidic nature of the alumina–silica support over the redox properties of the active vanadia phase.

A comparison of the adsorption of KF and NH4F onto silica gel

Abstract Silica gel has been fluorinated with KF, Na2SiF6, NH4F and (NH4)2SiF6, and the resulting reagents have been analysed by 19F and 29Si magic angle spinning NMR and infrared spectroscopy. Fluorination with NH4F and (NH4)2SiF6 results in the formation of (SiO)3SiF groups at the surface, where F has replaced OH, whereas the anion SiF2−6 is formed when silica is fluorinated with KF.

Determination of polycyclic aromatic hydrocarbons by high-performance liquid chromatography-particle beam-mass spectrometry

In this article, we report a high-performance liquid chromatography-particle beam-mass spectrometric (HPLC-PB-MS) method for the determination of polycyclic aromatic hydrocarbons (PAHs). The PB interface consists of a concentric ultrasonic nebulizer with temperature-controlled desolvation chamber and a three-stage momentum separator. The HPLCPB-MS method showed greater sensitivity for PAHs with molecular weights above 178 than for those PAHs with molecular weights below 178. The percent relative standard deviations for the determination of 0.5 ng chrysene, 1.0 ng dibenzo[a,h]anthracene, 1.0 ng benzo[g,h,i]perylene, and 2.5 ng coronene were 20%, 2.5%, 13.7%, and 6%, respectively. The detection limits at signal/noise = 3 were 0.2 ng for chrysene, 1.0 ng for dibenzo[a,h]anthracene, 0.5 ng for benzo[g,h,i]perylene, and 1.5 ng for coronene.

Ion-molecule reaction of alkanenitriles and transition-metal ions in the gas phase: A study on fragmentation mechanism of the adducts

Gas-phase ion-molecule reactions between transition-metal ions (Mn +, Fe+, Co+, Ni +) and propionitri1e and acetonitrile were investigated. Ion-molecule adducts were prepared in a modified fast atom bombardment source and their metastable and collision-induced fragmentations, occurring in the frrst held-free region of an E/B configuration instrument, were studied by means of B/E linked scans. The experimental data suggest a coexistence of both “end-on” and “side-on” coordination modes; the former undergoes ligand detachment alone, whereas the latter loses methyl and ethyl radicals by insertion of M+ into organic substrates and further produces ethylene via a l3-hydrogen transfer. An order for the bonding energy of RCN-M+ is also suggested: RCN-Ni+> RCN-Co+> RCN-Fe+> RCNMn+.

Very facile decarboxylation syntheses of polymethoxyphenylmercury compounds

Abstract The mercurials RHgO 2 CR [R = 2,6-(MeO) 2 C 6 H 3 , 2,3,4-(MeO) 3 C 6 H 2 , or 2,4,6-(MeO) 3 C 6 H 2 ], RHgO 2 CMe and R 2 Hg [R = 2,4,6-(MeO) 3 C 6 H 2 ] have been obtained in good yield from decarboxylation reactions between mercuric acetate and the corresponding polymethoxybenzoic acids in aqueous methanol at room temperature.

A direct presentation of consecutive metastable ion transitions in a double focusing mass spectrometer

Abstract Using a slightly modified AEI MS-30 mass spectrometer, a single chart, direct presentation of consecutive metastable ion transitions has been obtained for the first time. This technique offers a convenient method for the study of fragmentation pathways.