Graham R. Knox

Tricarbonyl(phenylacetylene)chromium and tricarbonyl(styrene)chromium

Abstract The preparation and several reactions of tricarbonyl(phenylacetylene)chromium and tricarbonyl(styrene)chromium are described.

Organocobalt complexes. Part II. Reaction of acetylenehexacarbonyldicobalt complexes, (R1C2R2)Co2(CO)6, with norbornene and its derivatives

Tetra- and hexa-hydro-4,7-methanoinden-1-ones and the analogous indacenediones (VIII)–(X) are formed stoicheiometrically by the title reaction or catalytically from acetylenes, norbornene derivatives, and carbon monoxide in the presence of octacarbonyldicobalt. The process leads stereoselectively to ketones of theexo-series and methyl or phenyl groups derived from the appropriate monosubstituted acetylenes are always found adjacent to the carbonyl group. The 1H n.m.r. spectra of the products are discussed and the use of an europium shift reagent together with spin decoupling is shown to allow clear distinction of the isomeric methanoindacenediones (VIII) and (IX).

Hydrocarbon metal sulphide complexes : I. Cyclopentadienylcarbonyliron mercaptides

Abstract Stable monomeric cyclopentadienyl dicarbonyliron alkyl(aryl)mercaptide complexes have been isolated and the controlled decompositions of these into pairs of isomeric binuclear di-μ-mercaptido-bis(carbonylcyclopentadienyliron) complexes studied. Specific methods are described for the kinetic or thermodynamic control of these decompositions. Improved procedures for the preparation of di-μ-mercaptido-bis(carbonylcyclopentadienyliron) are described. The stereochemistry of these complexes are discussed in relation to IR and PMR spectra.

Hydrocarbon metal sulphide complexes III. The stereochemistry of some rhodium derivatives

The preparations of [RSRh(CO)2]2 (R = CH3, C6H5, p-FC6H4, C6F5) are reported, and their stereochemistry investigated. Rapid cleavage of the thio bridge by triphenylphosphine leads to complexes of the type cis-RSRh(CO) (PPh3)2. The slow isomerisation of these to the trans-isomer can be followed spectrometrically.

Organocobalt complexes : VII. The role of butenolide complexes in the cobalt-catalysed synthesis of bifurandiones from acetylenes and carbon monoxide☆

Abstract The butenolide cobalt complexes derived from monosubstituted acetylenes are shown to be substituted in the α-position of the lactone ring. Their intermediacy in the catalytic formation of 2,6-disubstituted bifurandiones is demonstrated, and shown to require addition of both free acetylene and carbon monoxide.

A cobalt induced cleavage reaction and a new series of arenecobalt carbonyl complexes

Reaction of bicyclo[2,2,1]hepta-2,5-diene with alkynedicobalt hexacarbonyls in inert solvents gives dicarbonylcyclopentadienylcobalt, but in aromatic hydrocarbons arene-nonacarbonyltetracobalt complexes are formed.

Hydrocarbon metal sulphide complexes : VI. A new type of rearrangement of a cyclopentadienylruthenium complex

The complexes C5H5Ru(CO)2SR (R = C6F5 or CH3) undergo photochemical conversion to binuclear and trinuclear derivatives which exhibit isomerism. A novel rearrangement has been detected for [C5H5Ru(CO)(SC6F5)]2.

Organocobalt complexes. Part I. Arene complexes derived from dodecacarbonyltetracobalt

A series of tetranuclear arenecobalt carbonyls, ArHCo4(CO)9, are formed by treating hexacarbonylacetylenedicobalt complexes, (R1C2R2)Co2(CO)6, with arenes in the presence of norbornene derivatives, or from the cobalt carbonyls Co4(CO)12 and Co2(CO)8 by direct reaction with arenes. Stable complexes are obtained from alkyl- and alkoxy-benzenes, but not from halogeno- or acyl derivatives. The spectroscopic properties of the new complexes are reported.

Hydrocarbon metal sulphide complexes : II. Cyclopentadienylcarbonyliron trithiocarbonate complexes

Abstract Sodium alkyl or aryl trithiocarbonates react with cyclopentadienyldicarbonyliron halide, producing cyclopentadienyldicarbonyliron alkyl or aryl trithiocarbonates [C5H5Fe(CO)2CS3R] which readily lose carbon monoxide. UV irradiation converts these dicarbonyls (R  CH3, C2H5, C6H5) into chelated monocarbonyls, (alkyl- or aryltrithiocarbonato)cyclopentadienyliron carbonyl [C5H5Fe(CO)CS3R], which suffer carbon disulphide elimination in refluxing toluene yielding the known di-μ-mercaptido-bis(cyclopentadienylcarbonyliron) [C5H5Fe(CO)SR]2. The IR and PMR spectra of these complexes are discussed.

Hydrocarbon metal sulphide complexes IV. Some observations on the isomerisation of bis-μ-(arylthio)bis(carbonylcyclopentadienyliron)

Some observations on the stereochemistry of bis-μ-(arylthio)bis(carbonylcyclopentadienyliron) complexes are correlated with the NMR spectra of these materials. The kinetics and mechanism of isomerisation of an unstable phenylthio derivative to a stable form have been investigated in CS2 and in THF solutions.