Palladium Catalyzed Coupling Reactions: Mechanism of Reductive Elimination. Progress Report, June 1, 1978-September 30, 1979 (open access)

Palladium Catalyzed Coupling Reactions: Mechanism of Reductive Elimination. Progress Report, June 1, 1978-September 30, 1979

The coupling reaction of benzyl halides and organolithium, organotin, or Grignard Reagents is catalyzed by palladium. The sequence of events in the catalytic cycle is oxidative addition of the benzyl halide to palladium(0), methathesis by the organometallic reagent to give a benzyl methyl palladium(II) complex, oxidative addition of the benzyl halide to give a palladium(IV) complex, and reductive elimination of benzyl and methyl to give ethylbenzene. The reductive elimination from palladium bearing an optically active ..cap alpha..-deuteriobenzyl group takes place with retention of configuration at carbon, and is therefore concerted or nearly concerted. Since rho is positive in the catalytic reaction with substituted aryl halides, an oxidative addition, probably during the Pd(II) to Pd(IV) reaction, is the slow step in the catalytic cycle. The intermediate diorganopalladium species can be isolated when the two groups attached to palladium are both methyl or methyl and either cis or trans-..beta..-styryl. The decomposition of these species can be followed by NMR. In the case of methylstyrylpalladium(II) complexes, the reductive elimination gives propenyl benzene with stereospecific retention of double bond geometry. Cis-dimethylbis(diphenylmethylphosphine)palladium(II) does not undergo isomerization to the more stable trans isomer in an inert solvent, and is stable toward reductive elimination up to 50/sup …
Date: September 1, 1979
Creator: Stille, J. K.
Object Type: Report
System: The UNT Digital Library
Uranium Hydrogeochemical and Stream Sediment Reconnaissance of the Moab NTMS Quadrangle, Utah/Colorado, Including Concentrations of Forty-Three Additional Elements (open access)

Uranium Hydrogeochemical and Stream Sediment Reconnaissance of the Moab NTMS Quadrangle, Utah/Colorado, Including Concentrations of Forty-Three Additional Elements

Partial abstract: "During the summers of 1976, 1977, and 1978, 442 water and 1755 sediment samples were collected from 1801 locations within the 19 400 km2 area of the Moab quadrangle, Utah and Colorado, by private contractors for the Los Alamos Scientific Laboratory. Water samples were collected from streams, springs, and wells; wet and dry sediment samples were collected both from stream channels and from springs. Each water sample was analyzed for 13 elements, including uranium, and each sediment sample was analyzed for 43 elements, including uranium, thorium, and vanadium. All field and analytical data are listed in the appendixes of this report" (p. 1).
Date: September 1979
Creator: Goff, Sue & Warren, Richard G.
Object Type: Report
System: The UNT Digital Library
Uranium Hydrogeochemical and Stream Sediment Reconnaissance of the Pueblo NTMS Quadrangle, Colorado (open access)

Uranium Hydrogeochemical and Stream Sediment Reconnaissance of the Pueblo NTMS Quadrangle, Colorado

From introduction: This report describes work done in the Pueblo, Colorado, National Topographic Map Series (NTMS) quadrangle (1:250 000-scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).
Date: September 1978
Creator: Shannon, Spencer S., Jr.
Object Type: Report
System: The UNT Digital Library
Drinking-Water Quality and Variations in Water Levels in the Fractured Crystalline-Rock Aquifer, West-Central, Jefferson County, Colorado (open access)

Drinking-Water Quality and Variations in Water Levels in the Fractured Crystalline-Rock Aquifer, West-Central, Jefferson County, Colorado

From abstract: From parts of the area, water for domestic use obtained from the fractured crystalline-rock aquifer contained excessive concentration of dissolved fluoride, dissolved nitrite plus nitrate, dissolved solids, dissolved iron, dissolved manganese, dissolved zinc, coliform bacteria, gross alpha radiation, and gross beta radiation. Based on water-quality analyses from 26 wells located in small urbanized areas, water from 21 of the wells contained excessive concentrations of one of more constituents.
Date: September 1979
Creator: Hall, Dennis C. & Johnson, Carl J.
Object Type: Report
System: The UNT Digital Library
NURE Aerial Gamma Ray and Magnetic Reconnaissance Survey: Craig NK 13-10 Quadrangle, Volume 1 - Narrative Report (open access)

NURE Aerial Gamma Ray and Magnetic Reconnaissance Survey: Craig NK 13-10 Quadrangle, Volume 1 - Narrative Report

The data collected in this report was recorded from a rotary-wing, reconnaissance high sensitivity radiometric and magnetic survey was conducted in the Craig quadrangle in north-west Colorado.
Date: September 1979
Creator: LKB Resources, Inc.
Object Type: Report
System: The UNT Digital Library
NURE Aerial Gamma Ray and Magnetic Reconnaissance Survey: Craig NK 13-10 Quadrangle, Volume 2 (open access)

NURE Aerial Gamma Ray and Magnetic Reconnaissance Survey: Craig NK 13-10 Quadrangle, Volume 2

This is the second volume in a series of reports documenting radiometric and magnetic survey results for the Craig quadrangle in northwest Colorado. This volume contains profile plots of the data recorded from the survey.
Date: September 1979
Creator: LKB Resources, Inc.
Object Type: Report
System: The UNT Digital Library
The Yampa River Basin, Colorado and Wyoming--A Preview to Expanded Coal-Resource Development and Its Impacts on Regional Water Resources (open access)

The Yampa River Basin, Colorado and Wyoming--A Preview to Expanded Coal-Resource Development and Its Impacts on Regional Water Resources

This report presents the likely and substantial impact that expanded coal production and conversion will have on water in the Yampa River Basin, Colorado and Wyoming. It contains maps and graphs.
Date: September 1979
Creator: Steele, Timothy Doak; Bauer, Daniel P.; Wentz, Dennis A. & Warner, James W.
Object Type: Report
System: The UNT Digital Library

[Craig Quadrangle: Average Record Data Listings]

Average record data listings taken during aerial gamma-ray and magnetic surveys of the Craig quadrangle in Colorado.
Date: September 1979
Creator: LKB Resources, Inc.
Object Type: Dataset
System: The UNT Digital Library

[Craig Quadrangle: Single Record Data Listings]

Single record data listings taken during aerial gamma-ray and magnetic surveys of the Craig quadrangle in Colorado.
Date: September 1979
Creator: LKB Resources, Inc.
Object Type: Dataset
System: The UNT Digital Library