18716-94-4Relevant academic research and scientific papers
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
Cluster chemistry LIII. Preparation and some substitution reactions of bis(arylimido)triruthenium complexes: X-ray structures of Ru3(μ3-NPh)(μ3-NC6H4F-3)(CO)9 and Ru3(μ3-NPh)2(CO)8(L) (L=CNC6H3Me2-2,6 and PPh3)
Bruce, Michael I.,Humphrey, Mark G.,Shawkataly, Omar bin,Snow, Michael R.,Tiekink, Edward R.T.
, p. 199 - 220 (1987)
Azoarenes, ArN=NAr', react with Ru3(CO)12 to give Ru3(η3-NAr)(μ3-NAr')(CO)9 (Ar=Ph, Ar'=Ph, C6H4Me-3, C6H4CF3-3, C6H4F-3 (11), C6H4F-4; Ar=Ar'=C6H4Me-3) in moderate yields; for Ar=Ar'=Ph or C6H4Me-3, the mononuclear cyclometallated Ru(C6H3RN=NC6H4R-3)2(CO)2 (R=H or Me) were also obtained in low yield.Fe3(CO)12 and azobenzene afford Fe3(μ3-NPh)2(CO)9 in very low yield.An X-ray study of 11 confirms the structural assignments made on the basis of the spectroscopic measurements: an Ru3 triangle with a non-bonded Ru...Ru vector is capped on both sides by a μ3-arylimido moiety.Electron transfer-catalysed reactions with isocyanides, tertiary phosphines and phosphites proceed to give CO-substituted products in moderate yields: complexes Ru3(μ3-NPh)2(CO)8(L) (L=CNC6H3Me2-2,6 (15), PPh3 (16), P(OMe)3), 3-NPh)2(CO)8>2(μ-(PPh2)2C2) and Ru3(μ3-NPh)2(μ-LL)(CO)7 (LL=dppm, dppe) were obtained.X-ray structural studies of 15 and 16 show that the isocyanide ligand occupies an axial position, whereas the tertiary phosphine takes up an equatorial position, both on a terminal ruthenium atom.Crystal of 11, 15 and 16 crystallize in the monoclinic system with space group P21/n, a 11.496(2), b 14.020(2), c 15.735(2) Angstroem, β 99.43(1)o, Z=4 for 11; space group p21/n, a 11.933(2), b 18.952(2), c 14.370(4) Angstroem, β 100.29(2)o, Z=4 for 15; and space group Pc, a 17.507(3), b 11.657(2), c 19.518(4) Angstroem, β 100.41(2)o, Z=4 for 16.The structures were refined by least-squares methods and at convergence R=0.037, Rw=0.048 for 3653 statistically significant reflections for 11; R=0.041, Rw=0.046 for 3903 reflections for 15; and R=0.039, Rw=0.047 for 5291 reflections for 16.
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
Iron Carbonyl Induced o-Semidine Rearrangement of 1-Alkyl-2-aryldiazenes
Kisch, Horst,Reisser, Peter,Knoch, Falk
, p. 1143 - 1148 (2007/10/02)
Key Words: Ironcarbonyl complexes / ortho-Metallation / o-Semidine rearrangement. Irradiation of pentacarbonyl iron in the presence of Me3C-N=N-Ar (Ar= phenyl, p-tolyl, p-CH3OC6H4) produces in the first step ortho-matallated complexes of the type Me3C-(CO)3 (2a-c, R=H, Me, MeO).In a thermal consecutive step these intermediates undergo an o-semidine rearrangement to Me3C-(H)RC6H3 (1a-c).The structure of 1a has been elucidated by X-ray structure analysis.Dynamic 13C-NMR spectra indicate restricted rotation of the Me3C group and hindered carbonyl scrambling for the latter and former complexes, respectively.
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.
