Recent developments in the chemistry of selenoethers and telluroethers

Nature of the parasitic chemistry during AlGaInN OMVPE

Two reaction strategies are developed to promote the highly selective 1,3-isomerization of a variety of allylic alcohols using O3ReOSiPh3 as a catalyst. The first strategy utilizes substrates whose 1,3-regioisomer contains a conjugated alkene, which relies on thermodynamics to obtain high selectivity. The second strategy employs N,O-bis(trimethylsilyl)acetamide as an additive to selectively and irreversibly remove the product from the reaction equilibrium and works well for the isomerization of tertiary allylic alcohols into primary allylic alcohols containing trisubstituted alkene components. High stereoselectivity is also observed in the 1,3-isomerization of enantioenriched allylic alcohols.

Highly selective 1,3-isomerization of allylic alcohols via rhenium oxo catalysis.

A significant improvement in the selectivity of fullerene trifluoromethylation reactions was achieved. Reaction of trifluoroiodomethane with [60]fullerene at 460 °C and [70]fullerene at 470 °C in a flow reactor led to isolation of cold-zone-condensed mixtures of C60(CF3)n and C70(CF3)n compounds with narrow composition ranges:  6 ≤ n ≤ 12 for C60(CF3)n and 8 ≤ n ≤ 14 for C70(CF3)n. The predominant products in the C60 reaction, an estimated 40+ mol % of the cold-zone condensate, were three isomers of C60(CF3)10. Two of these were purified by two-stage HPLC to 80+% isomeric purity. The third isomer was purified by three-stage HPLC to 95% isomeric purity. Thirteen milligrams of this orange−brown compound was isolated (5% overall yield based on C60), and its C1-symmetric structure was determined to be 1,3,7,10,14,17,23,28,31,40-C60(CF3)10 by X-ray crystallography. The CF3 groups are either meta or para to one another on a p-m-p-p-p-m-p-m-p ribbon of edge-sharing C6(CF3)2 hexagons (each pair of adjacent hexago...

Synthesis, structure, and 19F NMR spectra of 1,3,7,10,14,17,23,28,31,40-C60(CF3)10.

Developments in the coordination chemistry of stibine ligands

Chemical vapor deposition (CVD) is a widely used technique for the production of thin semiconductor films such as gallium arsenide (GaAs) and related III-V compounds. These films have applications in such diverse areas as solar energy conversion and microelectronics. The first definitive identification and infrared spectroscopic characterization of the 1:1 molecular complex of (CH{sub 3}){sub 3}Ga with AsH{sub 3} is reported. Matrix isolation is well suited to the study of transient intermediates, particularly weakly bound or reactive molecular complexes. Preliminary photochemical studies of the dissociation/rearrangement of this complex by an excimer laser operating at 193 nm are also reported.

Matrix isolation studies of chemical vapor deposition: Isolation and characterization of the trimethylgallium-arsine adduct

Infrared spectroscopic characterization of the trimethylgallium/arsine adduct

The matrix isolation technique has been employed to isolate and characterize 1:1 molecular complexes of trimethylgallium with group VA bases. Several of these, including the (CH 3 ) 3 Ga-SbH 3 complex, are reported for the first time. All of the complexes were characterized by a red shift of the GaC 3 antisymmetric stretch and an activation of the GaC 3 symmetric stretch. In addition, numerous perturbed vibrational modes of the base subunit were observed

Matrix isolation study of the molecular complexes of trimethylgallium with group V bases

Infrared spectroscopic characterization of the 1:1 molecular complexes of trimethylindium with PH 3 , AsH 3 , and SbH 3 in argon matrices is reported. This represents the first indentification and characterization of these previously proposed intermediates. A number of vibrational modes of the acid and base subunits in these complexes are observed to shift relative to the parent species, although the shifts were generally smaller in magnitude than those observed for the analogous complexes of (CH 3 ) 3 Ga. The InC 3 symmetric stretching mode was not significantly activated in the complex, further indicating that these complexes are quite weakly bound

Elizabeth A. Piocos

Papers

Matrix isolation studies of chemical vapor deposition: Isolation and characterization of the trimethylgallium-arsine adduct

Infrared spectroscopic characterization of the trimethylgallium/arsine adduct

Matrix isolation study of the molecular complexes of trimethylgallium with group V bases

Infrared spectroscopic characterization of the molecular complexes of trimethylindium with group V hydrides

Infrared matrix isolation study of the (CH3)3In·NH3 complex in inert matrices