Now showing items 461-470 of 483
4,14-divinyl-(,)-[4.4]paracyclophane-1, 11-diene. An unusual product from a 1,10-Hofmann elimination
(Elsevier, 1986)
The isolation of 4,14-divinyl-(,)-[4.4]paracyclophane-1,11-diene from the cyclodimerization reaction of 7,8-divinyl--quinodimethane and its characterization are described. The title compound features head-to-tail, cofacially ...
Comment on enhanced Raman scattering from adsorbates on semiconductor surfaces
(Elsevier, 1984-11-02)
A recently published model of surface enhanced Raman scattering from adsorbed molecules on semiconductor surfaces is compared to our experimental results for amorphous carbon on PbTe. The model fails to account for the ...
The stereochemistry of ethylene-1,2-d2 epoxidation over silver catalysts
(Elsevier, 1980-10)
The stereochemistry of the catalytic epoxidation of cis-ethylene-1,2-d2 to ethylene oxide over four unsupported and two supported silver catalysts as well as over Ag2O and AgO was studied. Variations of the stereochemistry ...
Structure of the dextran of Leuconostoc mesenteroides B-1355
(Elsevier, 1980-09-15)
The structure of dextran B-1355-S (soluble fraction) has been investigated. Acid hydrolysis of the methylated dextran yielded 2,3,4,6-tetra-, 2,3,4-tri-, 2,4,6-tri-, and 2,4-di-O-methyl--glucose, in the molar ratios of ...
Analysis of cancer-associated colonic mucin by ion-exchange chromatography: evidence for a mucin species of lower molecular charge and weight in cancer
(Elsevier, 1989-05-31)
Cancer-associated mucins in the colon are antigenically distinct and glycosylated differently from their normal counterparts. Mucin-rich glycoconjugate preparations were made from nine non-neoplastic colons, seven colon ...
Toughened ceramics in the system Al2O3:Cr2O3/ZrO2:HfO2
(Elsevier, 1986)
Composites of Al2O3:Cr2O3 solid solution matrix with ZrO2:HfO2 solid solution dispersed particles were prepared and their properties studied. Thermal conductivity of compositions containing 20 mol% or more of chromia was ...
Vibrational analysis of crystalline diketopiperazine--I. Raman and i.r. spectra
(Elsevier, 1984)
Raman and i.r. spectra have been obtained of diketopiperazine and five of its isotopic derivatives: (CONDCH2)2, (CONHCD2)2, (CONDCD2)2, (13CONHCH2)2 and (13CONDCH2)2. In addition to solution spectra and powder spectra at ...
Determination of glucocerebroside, sphingomyelin, free fatty acid and total lipid by thin-layer chromatography and charring-scintillation quenching
(Elsevier, 1982-11-12)
A previously described method has been extended to various specific lipids of liver and brain. The basic method involves thin-layer chromatography followed by charring to reveal the bands. The intensity of each band is ...
Synthesis and rearrangements of ortho-selenonium phenoxides
(Elsevier, 1987)
A new class of selenonium zwitterions is prepared from the ortho- substitution of phenols with diphenylselenium bis(trifluoroacetate) 1. The zwitterions undergo a novel thermal rearrangement to produce diaryl ethers.
A general procedure for mild and rapid reduction of aliphatic and aromatic nitro compounds using ammonium formate as a catalytic hydrogen transfer agent
(Elsevier, 1984)
Various aliphatic and aromatic nitro compounds were selectively and rapidly reduced to their corresponding amino derivatives in very good yield using anhydrous ammonium formate as a catalytic hydrogen transfer agent.