Vilmos Galamb

AsCo3(CO)9, its cyclic trimer, As3Co9(CO)24 and the phosphorus-containing analog P3Co9(CO)24☆

The AsCo3(CO)9 trigonal pyramidal cluster, its cyclic “trimer” As3Co9(CO)24 and the phosphorus-containing analog of the latter, P3Co9(CO)24 have been prepared and characterized. A reversible equilibrium between the arsenic-containing monomer and trimer was found to depend on p(CO). Such an equilibrium could not be observed in the case of P3Co9(CO)24.

Stable alkylcobalt carbonyls: [(alkoxycarbonyl)methyl]cobalt tetracarbonyl compounds ☆

Abstract Stable alkylcobalt carbonyls of the general formula ROOCCH 2 Co(CO) 3 L(R = alkyl, CH 2 Ph; L = CO, EPh 3 ; E = P, As, Sb) were prepared. The molecular structure of PhCH 2 OOCCH 2 Co(CO) 3 (PPh 3 ) was determined by X-ray diffraction.

Transformations of the heteronuclear clusters En[Co(Co)3]4−n (E = P, As; n = 1–3) when treated with soft lewis acids and bases

Abstract The tetrahedral pnigogenic clusters E n [Co(CO) 3 ] 4 - n (EP, As; n = 1–3) react with soft Lewis acids and bases to give products of substitution and transformation of the cluster. Lewis acids promote transformations to clusters containing more cobalt atoms and Lewis basis to clusters containing fewer such atoms.

η1-and η3-Benzylcobalt carbonyls

η 1 -and η3-Benzylcobalt tetra- and tri-carbonyls were prepared and characterized; their reversible interconversions and transformation to η1-phenylacetylcobalt tetracarbonyls are discussed.

Alkylcobalt carbonyls: XI. Ligand-assisted carbonylation—decarbonylation reactions of alkylcobalt carbonyls

Abstract An [(alkoxycarbonyl)methyl]cobalt tetracarbonyl ( 1 ) derivative (alkyl = Et, 1a ) was treated with tertiary phosphorus ligands. A monosubstituted acyl derivative EtOC(O)CH 2 C(O)Co(CO) 3 L ( 2 ), L = PPh 3 ( 2f ) was isolated, and other new complexes of type 2 were detected spectroscopically (L = PEt 3 , 2a ; P( i Pr) 3 , 2c ; P( t Bu) 3 , 2d ; PMePh 2 , 2e ; P(NEt 2 ) 3 , 2g ; P(OMe) 3 , 2h ; P(OEt) 3 , 2i ; P(OSiMe 3 ) 3 , 2j ; P(S i Pr) 3 , 2k ). The corresponding alkyl derivatives, EtOC(O)CH 2 Co(CO) 3 L( 3 ), were obtained by thermal decarbonylation. Disubstituted acyl-, EtOC(O)CH 2 C(O)Co(CO) 2 L 2 ( 4 ), and alkyl-, EtOC(O)CH 2 Co-(CO) 2 L 2 ( 5 ) derivatives were obtained by direct substitution at ca. 30°C and ca. 70°C, respectively. The geometries of the new complexes were deduced from spectroscopic data. The monosubstituted derivatives 2 and 3 all show a trigonal bipyramidal array with axial organyl an PR 3 ligands. All the disubstituted complexes display a trigonal bipyramidal geometry with axial organyl groups, whereas an axial-equatorial distribution of the phosphines was assigned in the case of compounds 4a , b and 5a , b , e , h , i , and an equatorial-equatorial distribution in the case of complexes 4j and 5g , j . For the alkyl complexes 5 a solvation-like interaction between the ester group and the cobalt atom (autosolvation) was indicated by spectroscopic data.

The behaviour of the AsCo3(CO)9 cluster as a ligand for Cr, Mo, W, and Fe carbonyls and AlCl3

SummaryThe n-donor character of the AsCo3(CO)9 cluster has been tested by reacting it with soft (metal carbonyls) and hard (AlCl3) Lewis acids. The (CO)xM→AsCo3(CO)9 compounds (with M=Cr, Mo or W, x=5; M=Fe, x=4) and Cl3Al → AsCo3(CO)9 have been prepared.

On the reactivity of acetylenes coordinated to cobalt.: V. Unexpected formation of trinuclear μ3-carbyne derivatives from acetylene mono- and dicarboxylic acid esters

Stoichiometric carbonylation of acetylenes (R’CZR2) (I) with Co2(CO)s (II) or of the corresponding (/.I~-R’C~R’)CO~(CO)~ (III) compounds leads to the formation of the p2-carbene type (C402R1, R2)Co2(C0), complexes [3-71. The reaction can be carried out starting from a variety of hydrocarbons and moderately polar acetylenes (e.g. propargyl ethers) in apolar solvents such as n-hexane at 90-100 “C under 2040 MPa CO pressure. As an extension of our studies in this field we tested the behaviour of acetylenes with very polar substituents directly attached to the sp-carbon atom(s). Diiodoacetylene, which forms the corresponding (III) derivative under atmospheric conditions [8],

New Synthesis of 10-Alkoxy-5H-dibenz[b,f]azepines

Abstract The reaction of 5-acetyl-5H-dibenz[b,f]azepines with sodium-hypochlorite led to the 5-acetyl-10,11-epoxy-10,11-dihydro-5H-dibenz[b,f]azepine (1). The lithium iodide induced rearrangement of 1 gave the keton 2 which was reacted with trialkyl-orthoformates leading to the vinyl ethers 3a,b.

Alkylcobalt carbonyls : VI. Reaction of [(ethoxycarbonyl)methyl] cobalt tetracarbonyl with I2 dissolved in MeOH

Abstract Reaction of EtOOCCH2Co(CO)4 with I2 dissolved in MeOH yields XCH2COOEt (X  H, I, COOMe): the product with X  COOMe was formed even in the reaction in Ar.

Reactions of 5-Acetyl-10, 11-epoxy-10, 11-dihydro-5H-dibenz [b,f] Azepine with Alcohols and Trialkyl Orthoformates

Abstract The title compound (1) was reacted with trialkyl orthoformates and alcohols in the presence of boron trifluoride etherate. Depending on the solvent and temperature 10-acetyl-9-(dialkoxy)- methyl-9, 10-dihydroacridines(2) and/or 5-acetyl-10-alkoxy-11-hydroxy-10, 11-dihydro-5H-dibenz[b,f] azepines were formed (3).