Search results for "renium"
showing 8 items of 8 documents
ansa-[(tert-Butylamino)(isodicyclopentadienyl)dimethylsilane]Zr(NMe2)2prepared by an amine-elimination reaction
2003
An amine-elimination reaction was used to obtain the title compound, i.e. (N-tert-butyl-N-[[(1,2,3,3a,7a-eta)-4,5,6,7-tetrahydro-4,7-methano-1H-inden-2-yl]dimethylsilyl]amido-kappaN)bis(N-methylmethanaminato-kappaN)zirconium(IV) or [isodiCpSiMe(2)N-tert-butyl]Zr(NMe(2))(2) (Cp is cyclopentadienyl), [Zr(C(16)H(25)NSi)(C(2)H(6)N)(2)], in very good yield. Treatment of isodiCpHSiMe(2)NH-tert-butyl with Zr(NMe(2))(4) leads to the formation of a yellow solid that can be purified by sublimation. The single-crystal structure of the product shows the exo complexation of the isodicyclopentadienyl ligand to the Zr atom. The Cp portion of this ligand is bonded to the Zr atom in a eta(5) manner, with a …
CCDC 783769: Experimental Crystal Structure Determination
2011
Related Article: V.Blanco, M.D.Garcia, A.Terenzi, E.Pia, A.Fernandez-Mato, C.Peinador, J.M.Quintela|2010|Chem.-Eur.J.|16|12373|doi:10.1002/chem.201002051
CCDC 783766: Experimental Crystal Structure Determination
2011
Related Article: V.Blanco, M.D.Garcia, A.Terenzi, E.Pia, A.Fernandez-Mato, C.Peinador, J.M.Quintela|2010|Chem.-Eur.J.|16|12373|doi:10.1002/chem.201002051
CCDC 783767: Experimental Crystal Structure Determination
2011
Related Article: V.Blanco, M.D.Garcia, A.Terenzi, E.Pia, A.Fernandez-Mato, C.Peinador, J.M.Quintela|2010|Chem.-Eur.J.|16|12373|doi:10.1002/chem.201002051
A Computational Study of Ethylene C−H Bond Activation by [Cp*Ir(PR3)]
2001
It has previously been demonstrated that both [(C5Me5)Ir(PMe3)(CH=CH2)H] and [(C5Me5)Ir(PMe3)(H2C=CH2)] are formed when [(C5Me5)Ir(PMe3)] is thermolytically generated in the presence of ethylene. At higher temperatures, the vinyl hydride is converted to the eta2-ethylene adduct. Density functional theory has now been used to investigate this reaction, using the B3LYP functional, two types of basis sets (LanL2DZ and TZV*), and two models of the [(C5R5)Ir(PR3)] species (R=H and CH3). The study consists of full optimizations of local minima, first-order saddle points, and minimum energy crossing points (MECP). The experimental results are best accounted for by considering both singlet and trip…
Negatively Curved Nanographene with Heptagonal and [5]Helicene Units
2020
Negatively curved nanographene (NG) 4, having two heptagons and a [5]helicene, was unexpectedly obtained by aryl rearrangement and stepwise cyclodehydrogenations. X-ray crystallography confirmed the saddle-shaped structures of intermediate 3 and NG 4. The favorability of rearrangement over helicene formation following radical cation or arenium cation mechanisms is supported by theoretical calculations. NG 4 demonstrates a reversible mechanochromic color change and solid-state emission, presumably benefiting from its loose crystal packing. After resolution by chiral high-performance liquid chromatography, the circular dichroism spectra of enantiomers 4-(P) and 4-(M) were measured and showed …
CCDC 783768: Experimental Crystal Structure Determination
2011
Related Article: V.Blanco, M.D.Garcia, A.Terenzi, E.Pia, A.Fernandez-Mato, C.Peinador, J.M.Quintela|2010|Chem.-Eur.J.|16|12373|doi:10.1002/chem.201002051
ReO as a Brønsted acidic modifier in glycerol hydrodeoxygenation : Computational insight into the balance between acid and metal catalysis
2023
A computational study for the competitive conversion of glycerol to 1,2-propanediol and 1,3-propanediol is presented, considering a two-step sequence of dehydration followed by hydrogenation. The elementary steps for dehydration, i.e., breaking of C–H followed by C–OH or vice versa, were studied computationally both on the Rh metal surface and the acid-modified ReOH–Rh surface in order to understand the role of the acid promoter. While the acid modifier can catalyze the C–OH cleavage, the activation energy for the C–H cleavage was found to be considerably smaller on both pure and acid-doped Rh(111) surfaces, and breaking the secondary C–H bond is kinetically favored over breaking the termin…