In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 44, No. 6 ( 1989-6-1), p. 699-714
Abstract:
Raney nickel, a highly reactive and air-sensitive solid, if prepared and investigated under oxygen-free conditions, exhibits interesting catalytic properties. Using photoelectron spectroscopy for real-time gas analysis in a flow reactor, the following results are obtained with alkyl and acylhalides: Dehydrohalogenation temperatures are lowered relative to thermal HHal elimination up to 350 K. Monochloro and bromo propanes and butenes yield propene and butadiene, respectively. 1,1-Dichloro ethane or 1,1-dibromo propane only split off one HHal and form chloroethene or l-brom opropene-2. HCl elim ination from 2-methyl propionic acid chloride, expectedly, produces dimethyl ketene. Most interesting, how ever, is the ring opening of monobromo cyclobutane to 1-brom o-butene-3, observed already at room temperature, which strongly suggests the intermediate formation of a chem isorbed surface carbene at Raney nickel. The formation of hexadiene-1,5 as a by-product in the HCl elim ination of 1-chloropropane, i.e. a surface carbene dimer, indicates their presence also in other dehydrohalogenations heterogeneously catalyzed by Raney nickel
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.1515/znb-1989-0614
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
1989
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
Bookmarklink