18716-94-4Relevant articles and documents
Reactions of N-phenyl-o-semiquinonediimine complexes of nickel and platinum with carbonyl-containing low-valence iron and rhenium compounds
Reshetnikov,Talismanova,Sidorov,Nefedov,Eremenko,Moiseev
, p. 142 - 146 (2001)
The reactions of o-semiquinonediimine complexes M[o-(NH)(NPh)C6H4]2 (M = Ni (1) or Pt (2)) with carbonyl-containing iron and rhenium compounds were studied. The reactions of complexes 1 or 2 with Fe(CO)5 afforde
Azoalkane- and Nitrene-Bridged Carbonyl Metal Clusters of Iron and Ruthenium
Hansert, Bernhard,Powell, Anne K.,Vahrenkamp, Heinrich
, p. 2697 - 2704 (2007/10/02)
By using cluster buildup reactions, the new azoalkane-bridged clusters Ru3(CO)9(RN=NR) (3a, R = Me, 3b, R = Et), Fe2Ru(CO)9(EtN=NEt) (4), Ru4(CO)12(RN=NR) (5a, R = Me, 5n, R = Et), and FeRu3(CO)12(EtN=NEt) (6) were obtained.Upon attempts to prepare further such compounds, the N-N bond was cleaved resulting in nitrene-bridged clusters including the new compound Fe4(CO)11(Μ4-NEt)2 (9).Cluster buildup starting from Ru3(CO)9(μ3-NPh)2 resulted in Ru4(CO)11(μ4-NPh)2 (10) and FeRu3(CO)11(μ4-NPh)2 (11).The crystal structures of 5n and 9 as well as some reactions of the nitrene-bridged clusters are described.Key Words: Clusters, trinuclear and tetranuclear / Iron clusters / Ruthenium clusters / Azoalkane and nitrene bridging
Intramolecular conversion of an azoalkane ligand to two nitrene ligands on a triiron cluster
Wucherer, Edward J.,Tasi, Miklos,Hansert, Bernhard,Powell, Anne K.,Garland, Maria-Theresa,Halet, Jean-Francois,Saillard, Jean-Yves,Vahrenkamp, Heinrich
, p. 3564 - 3572 (2008/10/08)
The azoalkanes R2N2 (1; R = Et, Pr) have been reacted with Fe(CO)3(c-C8H14)2 or Fe3(CO)12 to yield the azoalkane complexes Fe2(CO)6(μ-η2-R2N 2) (2) and Fe3(CO)9(μ3-η2-R 2N2) (3). Thermolysis of the clusters 3 in solution has resulted in N-N cleavage without loss of CO to form the nitrene-bridged clusters Fe3(CO)9(μ3-NR)2 (4). From the reactions of azobenzene with the iron carbonyl starting materials only products resulting from N-N cleavage have been isolated. The crystal and molecular structures of Fe2(CO)6(μ-η2-Et2N 2) (2a), Fe3CO)9(μ3-η2-Et 2N2) (3a), and Fe3(CO)9(μ3-NEt)2 (4a) have been determined and refined to R values of 0.076, 0.046, and 0.058, respectively. (2a, monoclinic, P21/c, a = 7.541 (5) A?, b = 14.609 (5) A?, c = 14.205 (4) A?, β = 106.70 (4)°, Z = 4; 3a, monoclinic, P21/n, a = 8.860 (3) A?, b = 12.900 (2) A?, c = 16.147 (2) A?, β = 92.68 (2)°, Z = 4; 4a, orthorhombic, Pbca, a = 27.214 (8) A?, b = 12.391 (8) A?, c = 11.140 (6) A?, Z = 8). With use of a mixture of the N-Et and N-Pr compounds it was ascertained that the azoalkane-nitrene cleavage is intramolecular. It is inhibited under a CO atmosphere. Kinetic analysis has shown the reaction to be approximately first order with an activation energy of ca. 35 kcal/mol. The observations can be explained by CO elimination as the first step in the rearrangement. A molecular orbital analysis with EH calculations has led to two possible pathways. One is a simple rearrangement between seven-SEP nido-type square-based-pyramidal isomers and involves a reaction intermediate or transition state in which one nitrogen atom caps an Fe3N distorted square. The other one, which is fully consistent with the kinetic experiments, involves two intermediates with a six-SEP closo-type trigonal-bipyramidal structure; the first, resulting from CO loss and an R2N2 slippage, has an Fe2N pyramidal base, while the second, due to rearrangement and N-N cleavage, has an Fe3 pyramidal base. The final reaction step, readdition of a CO ligand, involves the opening of one Fe-Fe bond.
