G. Cetini

Reactions of Ru3(CO)12 with asymmetrically substituted acetylenes. A new type of interaction between acetylenes and a metal-atom cluster

Abstract The compounds Ru 3 (CO) 9 X (where XC 2 (t-Bu)H and C 2 (Ph)H) have been obtaned from the reactions of Ru 3 (CO) 12 with t-BuCCH and PhCCH. Their IR, NMR and mass spectra are reported and discussed. A hydrido signal in the NMR spectrum and other evidence point to a new type of structure, different from that proposed by Blount and his coworkers for Fe 3 (CO) 9 C 2 Ph 2 .

The chemistry of dodecacarbonyltriruthenium I. Acetylene derivatives of dodecacarbonyltriruthenium

Abstract Substitutions of carbonyl groups in Ru 3 (CO) 12 by diphenylacetylene and tetraphenylcyclopentadienone are described. Nine compounds, six of which are trinuclear ruthenium carbonyl acetylenes, were isolated from the reaction with diphenylacetylene in inert solvents. In methyl alcohol two Ru 3 (CO) 8 (C 2 Ph 2 ) 2 isomers were obtained, a violet one having only terminal carbonyls and an orange-yellow one with bridging carbonyl groups. The thermal decomposition of the products and replacements of carbonyl groups with basic ligands (mainly triphenylphosphine) were studied. A compound Ru 3 (CO) 5 (C 2 Ph2) 2 (PPh 3 ) 3 , containing bridging carbonyl groups, is also described. The greater tendency of the ruthenium carbonyl than of iron carbonyl to retain the trinuclear cluster in these reactions is discussed, with emphasis on the fact that the ruthenium carbonyl can give rise to bridged carbonyl compounds even when such groups are not present in the original structure.

Reactions of Ru3(CO)12 with chalcogen compounds

Abstract Attempts to synthesize the compounds Ru3(CO)9X2(X = S,Se,Te) bytreating Ru3(CO)12 in alkaline solution with chalcogen compounds gave the substituted hydrides of the series H2Ru3(CO)9X (X = S,Se,Te), which were isolated and characterised. The same products were obtained under other conditions also. The NMR and mass spectra are discussed, and possible structures for these paramagnetic complexes are suggested.

Acetylenic derivatives of metal carbonyls I. Substitution reactions of CO2(CO)6C2RR′ complexes

Abstract In this work the substitution reactions were studied, of one acetylenic derivative, by another, in the complexes Co 2 (CO) 6 C 2 RR′ in which R and R′CF 3 , COOCH 3 , C 6 H 5 , CH 2 Cl, CH 3 , CH 2 N(C 2 H 5 ) 2 and H. On the basis of such reactions, relative stabilities of the various acetylenic derivatives were determined and discussed in terms of the acceptor character of the different acetylenes. Also reported are the preparations and properties of some new compounds of this series.

Chalcogen derivatives of iron carbonyls I. Substituted derivatives of Fe3(CO)9X2 Complexes (X=S, Se, Te) with ligands

Abstract Series of mono- and disubstituted derivatives of Fe3(CO)9X2 complexes (X= S, Se, Te) with ligands are prepared. Different reactions are found with the Te compound, which also gives additional derivatives. An explanation is proposed, referred to the difference in electron attracting power of the chalcogen atoms. Also the preparations, the properties and the main infrared absorption frequencies of the new compounds are reported.

Acetylenic derivatives of metal carbonyls XII. Diphenylacetylenic derivatives of dodecacarbonyltriosmium

The reaction of the complex (C6H5C2C6H5)2Os3(CO)8 (I) with CO has been investigated and a structure suggested for the compound, (C6H5C2C6H5)2Os3(CO)9, thus obtained. This consists basically of an Os3 cluster, in which one of the osmium atoms belongs to a osmacyclopentadiene ring, and to which only terminal carbonyl groups are bonded. The formation of this product from (I) and CO was found to be a second-order process. The reactions of complex (I) with halogens have also been investigated, and the resulting binuclear derivatives identified.

Chalcogen derivatives of iron carbonyls. II. Carbon monoxide isotopic exchange and substitution reactions with ligands in Fe3(CO)9X2(X = S, Se, Te,) complexes

Abstract Kinetic results on the CO isotopic exchange and substitution reactions with ligands in Fe 3 (CO) 9 X 2 (X = S, Se, Te) complexes are reported. The reaction rates follow an S N 1 and/or S N 2 mechanism depending upon the electronegativity of X and the nucleophilicity of L. The values of k 1 are in agreement with the ν c-o and are referred to a dissociation mechanism. An explanation in terms of electron distribution within the complex is proposed.

Reactions of triruthenium dodecacarbonyl with diphenylacetylene in alkaline solution

Abstract From the reaction between Ru 3 (CO) 12 and C 2 Ph 2 in aqueous methanolic alkali, the novel substituted hydrido-carbonyl, H 2 Ru 3 (CO) 9 C 2 Ph 2 has been obtained. This product shows structural features similar to those of the previously reported H 2 Ru 3 (CO) 9 E (E = S, Se, Te) and H 2 Ru 3 (CO) 9 (C 8 H 8 ) compounds. The properties of the compound are reported, and its role as intermediate in the formation of Ru 3 (CO) 8 (C 2 Ph 2 ) 2 is discussed.

Acetylenic derivatives of metal carbonyls. XIV. Cyclotrimerization of diphenylacetylene with dodecarbonyltriosmium

Abstract L 2 Os 3 (CO) s complexes, where L = (C 6 H 5 ) 2 C 2 , ( p -ClC 6 H 4 ) 2 ( p -CH 3 C 6 H 4 ) 2 C 2 , react with excess of ligand to yield compounds of general formula L 3 Os 3 (CO) 7 . On the basis of chemical and physical chemical data, a structure is suggested in which only two ligand molecules are linked together. [(C 6 H 5 ) 2 ] 3 Os 3 (CO) 7 reacts with more diphenylacethylene to form hexaphenylbenzene. In the course of this process [C 6 H 5 ) 2 C 2 ] 3 Os 3 (CO) 6 can be isolated. This seems to be the last stable trinuclear intermediate in the cyclotrimerization reaction and seems to contain the three ligand molecules joined together. It does in fact give hexaphenylbenzene readily by thermal decomposition.

Chalcogen derivatives of iron carbonyls. V. Kinetics and mechanism of CO exchange and of substitution reactions of Fe3(CO)9XY complexes (X and Y=S, Se, Te with X≠Y)

Abstract Fe 3 (CO) 9 XY complexes undergo carbonyl substitution with triphenylarsine and triphenylphosphite to give the mono- and di-substituted derivatives, Fe 3 (CO) 8 LXY and Fe 3 (CO) 7 L 2 XY. The preparation and spectra of these compounds are reported. The substitution reactions and the CO exchange reaction proceed according to the two term rate law: rate = k 1 [complex] + k 2 [complex][ligand], in which the relative values of k 1 and k 2 depend on the nature of X, Y, and L. The results are in agreement with the reactivity of the Fe 3 (CO) 9 X 2 complexes.