Carbonyl halides of the Group VIII transition metals. II. Aquo adducts of Halobis(triphenylphosphine)dicarbonyls of cobalt(I)

1968 ◽  
Vol 21 (4) ◽  
pp. 891 ◽  
Author(s):  
JA Bowden ◽  
R Colton
Keyword(s):  
Solid State ◽  
Transition Metals ◽  
Group Viii ◽  
Exchange Reactions

Aquo adducts of halobis(triphenylphosphine)dicarbonylcobalt(1), Co(CO)2- (PPh3)2(H2O)X (X = Cl, Br, I), have been prepared by direct halogenation of the cation CO(CO)3(PPh3)2+, followed by addition of water. All of the compounds are stable in the solid state but they appear to undergo exchange reactions in solution.

Catalytic deuterium exchange reactions with organics. XLII. The picolines, lutidines, thiophen, and furan on unsupported Group VIII transition metals

1968 ◽  
Vol 21 (5) ◽  
pp. 1221 ◽  
Author(s):  
GE Calf ◽  
JL Garnett
Keyword(s):  
Transition Metals ◽  
Lone Pair ◽  
Nickel Chloride ◽  
Platinum Oxide ◽  
Transition Metal Catalysts ◽  
The Novel ◽  
Group Viii ◽  
Exchange Reactions ◽  
Alkyl Groups ◽  
Nitrogen Lone Pair

The picolines (methylpyridines), lutidines (dimethylpyridines), thiophen, and furan have been exchanged with heavy water on a variety of Group VIII transition metals. Platinum is the most reactive general labelling catalyst for the picolines and lutidines, whereas cobalt catalyses exchange exclusively in the positions α to the nitrogen atom. The labelling pattern in the picolines and lutidines is similar to that of the alkylbenzenes in that (i)positions ortho to a methyl group are severely deactivated and (ii)positions flanked by two methyl groups are completely deactivated. Compensation effects are observed involving steric hindrance to adsorption from the alkyl groups and enhanced strength of adsorption from the nitrogen lone pair. The compensation effect in this charge-transfer adsorption slightly favours the nitrogen lone pair. Thiophen and furan generally do not exchange appreciably with pre-reduced Group VIII transition metal catalysts. Thiophen exchanges rapidly on self-activated platinum oxide whereas self-activated iridium oxide is the most useful for furan. With nickel chloride, furan exchanges exclusively in the or positions. A theory is proposed to account for the novel exchange in both thiophen and furan.

Catalytic deuterium exchange reactions with organics. XL. Pyridine, the quinolines, azines, and aniline on unsupported Group VIII transition metals

1968 ◽  
Vol 21 (4) ◽  
pp. 961 ◽  
Author(s):  
GE Calf ◽  
JL Garnett ◽  
VA Pickles
Keyword(s):  
Charge Transfer ◽  
Transition Metals ◽  
Heavy Water ◽  
Heterocyclic Compounds ◽  
Group Viii ◽  
Borohydride Reduction ◽  
Exchange Reactions ◽  
Catalyst Activation ◽  
Π Complex ◽  
Sodium Borohydride Reduction

Pyridine, the quinolines, pyridazine, pyrimidine, pyrazine, s-triazine, and aniline have been exchanged with heavy water on the following Group VIII transition metals: Fe, Co, Ni, 0s. Ru, Rh, Pd, Ir, and Pt. Three types of catalyst activation have been used, including self-activation, hydrogen and sodium borohydride reduction of the inorganlo salts. Platinum is the most useful catalyst for general exchange whereas cobalt possesses valuable specificity for selective a exchange in a large number of the heterocyclic compounds. A kinetic study of the deuteration of pyridine on platinum has been performed. The exchange results have been rationalized in terms of charge-transfer adsorbed intermediates. E.s.r. has been used to support this conclusion for the interaction between pyridine and potassium chloropalladite. π-Complex mechanisms have been proposed to explain the observed deuteration behaviour.

Catalytic deuterium exchange reactions with organics. XIII. Characteristic reactions of the Group VIII transition metals

1965 ◽  
Vol 18 (7) ◽  
pp. 1003 ◽  
Author(s):  
JL Garnett ◽  
WA Sollich
Keyword(s):  
Transition Metal ◽  
Hydrogen Exchange ◽  
Deuterium Oxide ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Group Viii ◽  
Exchange Reactions ◽  
Substitution Mechanism ◽  
Π Complex ◽  
Complex Adsorption

Activation procedures and hydrogen exchange reactions with six Group VIII transition metal catalysts (Pt, Pd, Ru, Rh, Ir, Ni) are reported for three characteristic reaction systems: (i) deuterium oxide/benzene, (ii) deuterium oxide/naphthalene, and (iii) deuterium oxide/n-octane. Results of these exchange reactions indicate that both π-complex adsorption and the dissociative π-complex substitution mechanism previously established for platinum are applicable to other Group VIII transition metal catalysts. For general catalytic labelling with isotopic hydrogen, platinum was found to be the most efficient of the catalysts investigated.

Butterfly Cluster Complexes of the Group VIII Transition Metals

2007 ◽  
pp. 437-525 ◽  
Author(s):  
Enrico Sappa ◽  
Antonio Tiripicchio ◽  
Arthur J. Carty ◽  
Gerald E. Toogood
Keyword(s):  
Transition Metals ◽  
Group Viii ◽  
Cluster Complexes ◽  
Butterfly Cluster

Reactivity of transition metal fluorides. VIII. Reactions of rhenium heptafluoride and hexafluoride

1971 ◽  
Vol 24 (2) ◽  
pp. 243 ◽  
Author(s):  
JH Canterford ◽  
TA O'Donnell ◽  
AB Waugh
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Exchange Reactions ◽  
Metal Fluorides ◽  
Oxidation Reduction ◽  
Halogen Exchange ◽  
Transition Metal Fluorides

Oxidation-reduction and halogen-exchange reactions of the higher fluorides of rhenium with a series of selected reagents have been investigated. The results correlate with studies of reactivities of higher fluorides of other transition metals previously reported. The reactions reported provide markedly improved preparative routes to the hexachloride, pentabromide, and pentafluoride of rhenium.

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