Entity

Time filter

Source Type

London, Canada

Thibault M.E.,University of Guelph | Dimondo D.V.,University of Guelph | Jennings M.,185 Chelsea Avenue | Abdelnur P.V.,University of Campinas | And 2 more authors.
Green Chemistry | Year: 2011

The ruthenium aqua complexes [cp*Ru(OH2)(N-N)](OTf) (cp* = η5-pentamethylcyclopentadienyl, N-N = 2,2′-bipyridine, phen = 1,10-phenanthroline, OTf- = trifluoromethanesulfonate) and the acetonitrile complex [cpRu(CH 3CN)(bipy)](OTf) (cp = η5-cyclopentadienyl) are water-, acid-, and thermally stable (>200°C) catalysts for the hydrogenation of aldehydes and ketones in sulfolane solution. In the presence of HOTf as a co-catalyst, they effect the deoxygenation of 1,2-hexanediol to 1-hexanol and hexane. Glycerol is deoxygenated to 1-propanol in up to 18% yield and under more forcing conditions completely deoxygenated to propene. The structure of the acetonitrile pro-catalyst [cpRu(CH3CN)(bipy)](OTf) has been determined by X-ray crystallography (space group P1 (a = 9.3778(10) Å; b = 10.7852(10) Å; c = 11.1818(13) Å; α = 101.718(5)°; β = 114.717(4)°; γ = 102.712(5)°; R = 3.95%). © 2011 The Royal Society of Chemistry. Source


Sullivan D.J.,University of Guelph | Clerac R.,CNRS Paul Pascal Research Center | Jennings M.,185 Chelsea Avenue | Lough A.J.,University of Toronto | Preuss K.E.,University of Guelph
Chemical Communications | Year: 2012

The first metal coordination complex of a radical ligand based on the 1,2,3-dithiazolyl heterocycle is reported. 6,7-Dimethyl-1,4-dioxo-naphtho[2,3-d] [1,2,3]dithiazolyl acts as a bridging ligand in the volatile trinuclear Mn(hfac)2-Rad-Mn(hfac)2-Rad-Mn(hfac)2 complex (hfac = 1,1,1,5,5,5-hexafluoroacetylacetonato-). The Mn(ii) and radical ligand spins are coupled anti-ferromagnetically (AF) resulting in an ST = 13/2 spin ground state. © 2012 The Royal Society of Chemistry. Source


Fatila E.M.,University of Guelph | Jennings M.C.,185 Chelsea Avenue | Lough A.,University of Toronto | Preuss K.E.,University of Guelph
Acta Crystallographica Section C: Crystal Structure Communications | Year: 2012

A previous analysis [Fatila et al. (2012). Dalton Trans. 41, 1352-1362] of the title complex, [Ce2(C5HF6O2)6(C4H10O2)3], had identified it as Ce(hfac)3(dme)1.5 according to the 1H NMR integration [hfac = 1,1,1,5,5,5-hexa-fluoro-acetyl-ace-ton-ate (1,1,1,5,5,5-hexa-fluoro-4-oxopent-2- en-2-olate) and dme = 1,2-dimethoxyethane]; however, it was not possible to determine the coordination environment unambiguously. The structural data presented here reveal that the complex is a binuclear species located on a crystallographic inversion center. Each CeIII ion is coordinated to three hfac ligands, one bidentate dme ligand and one monodentate (bridging) dme ligand, thus giving a coordination number of nine (CN = 9) to each Ce III ion. The atoms of the bridging dme ligand are unequally disordered over two sets of sites. In addition, in two of the -CF3 groups, the F atoms are rotationally disordered over two sets of sites. This is the first crystal structure of a binuclear lanthanide Β-diketonate with a bridging dme ligand. © 2012 International Union of Crystallography. Source


Fatila E.M.,University of Guelph | Jennings M.C.,185 Chelsea Avenue | Goodreid J.,University of Guelph | Preuss K.E.,University of Guelph
Acta Crystallographica Section C: Crystal Structure Communications | Year: 2010

The crystal structure of a third polymorphic form of the known 4-(2,6-difluoro-phenyl)-1,2,3,5-dithia-diazolyl radical, C7H 3F2N2S2, is reported. This new polymorph represents a unique crystal-packing motif never before observed for 1,2,3,5-dithia-diazolyl (DTDA) radicals. In the two known polymorphic forms of the title compound, all of the mol-ecules form cis-cofacial dimers, such that two mol-ecules are π-stacked with like atoms one on top of the other, a common arrangement for DTDA species. By contrast, the third polymorph, reported herein, contains two crystallographically unique mol-ecules organized such that only 50% are dimerized, while the other 50% remain monomeric radicals. The dimerized mol-ecules are arranged in the trans-antarafacial mode. This less common dimer motif for DTDA species is characterized by π-π inter-actions between the S atoms [S⋯S = 3.208 (1) Å at 110 K], such that the two mol-ecules of the dimer are related by a centre of inversion. The most remarkable aspect of this third polymorph is that the DTDA dimers are co-packed with monomers. The monomeric radicals are arranged in one-dimensional chains directed by close lateral inter-molecular contacts between the two S atoms of one DTDA heterocycle and an N atom of a neighbouring coplanar DTDA heterocycle [S⋯N = 2.857 (2) and 3.147 (2) Å at 110 K]. © 2010 International Union of Crystallography. Source


MacDonald D.J.,University of Guelph | Jennings M.C.,185 Chelsea Avenue | Preuss K.E.,University of Guelph
Acta Crystallographica Section C: Crystal Structure Communications | Year: 2010

In a new polymorphic form of dichloridotriphenyl-antimony, [Sb(C 6H5)3Cl2], there are two crystallographically unique molecules in the asymmetric unit and it has been determined that this polymorph is one of two kinetically favoured phases of pure dichloridotriphenyl-antimony, both of which have Z′ > 1. A third polymorph, corresponding to (C6H5)3SbCl 1.8F0.2, is also known and has Z′ = 2. By contrast, the thermodynamically preferred polymorph of pure (C6H 5)3SbCl2 has Z′ = 1. A brief comparison of the known polymorphic forms of dichloridotriphenyl-antimony is presented. © 2010 International Union of Crystallography. Source

Discover hidden collaborations