Highly Cooperative Tetrametallic Ruthenium-μ-Oxo-μ-Hydroxo Catalyst for the Alcohol Oxidation Reaction

The tetrametallic ruthenium-oxo-hydroxo-hydride complex {[(PCy3)(CO)RuH]4(μ4-O)(μ3-OH)(μ2-OH)} (1) was synthesized in two steps from the monomeric complex (PCy3)(CO)RuHCl (2). The tetrameric complex 1 was found to be a highly effective catalyst for the transfer dehydrogenation of alcohols. Complex 1 showed a different catalytic activity pattern toward primary and secondary benzyl alcohols, as indicated by the Hammett correlation for the oxidation reaction of p-X-C6H4CH2OH (ρ = −0.45) and p-X-C6H4CH(OH)CH3 (ρ = +0.22) (X = OMe, CH3, H, Cl, CF3). Both a sigmoidal curve from the plot of initial rate vs [PhCH(OH)CH3] (K0.5 = 0.34 M; Hill coefficient, n = 4.2 ± 0.1) and the phosphine inhibition kinetics revealed the highly cooperative nature of the complex for the oxidation of secondary alcohols

Synthesis and Molecular Structure of (TTP)Ti(1,2-η2-PhC⋮C−C⋮CPh)

The tetratolylporphyrinato complex, (TTP)TiCl2, oxidatively couples lithium acetylide reagents (LiC⋮CR; R = Ph, SiMe3) to 1,3-butadiyne products. The reduced Ti(II) fragment scavenges the diyne to form an η2-complex involving π-bonding to only one of the alkyne units, (TTP)Ti(1,2-η2-RC⋮C−C⋮CR). Independent syntheses of the diyne complex starting from (TTP)TiCl and (TTP)Ti(η2-EtC⋮CEt) confirm the composition of the π-adduct. The lability of the butadiyne ligand in these Ti porphyrin complexes is readily demonstrated by displacement with pyridine

Detailed example of the identification and crystallographic analysis of a pseudo-merohedrally twinned crystal.

A detailed description of the procedures utilized in the nonroutine X-ray single-crystal structural determination and refinement of a pseudo-merohedrally twinned crystal of an Fe/Ni organometallic complex is presented. It illustrates to the practitioners of crystallography how to properly handle such cases and describes the logic and concrete steps necessary to account for the twinning, pseudo-symmetry and atomic positional disorder

2-[2-(Trimethyl­silyl)eth­yl]isoindoline-1,3-dione

In the course of our studies of silicon-containing anti­cancer compounds, the title compound, C13H17NO2Si, was synthesized. The geometrical parameters including the geometry about the Si atom are typical. The mol­ecules form dimers via a weak C—H⋯O inter­action described by the graph set R 2 2(10). The dimers are assembled in rows stacked in the crystallographic b-axis direction via π–π inter­actions with a 3.332 (3) Å separation between the rows

2-[3-(Methyl­diphenyl­silyl)prop­yl]isoindoline-1,3-dione

In the title compound, C24H23NO2Si, the dihedral angle between the planes of the phenyl rings attached to the Si atom is 80.78 (10)°. In the crystal, the mol­ecules form sheets lying perpendicular to [101] via C—H⋯O inter­actions. These sheets are stacked and linked in a three-dimensional framework by additional C—H⋯O inter­actions in the [10] direction

Dichlorido[2-(3,5-dimethyl-1H-pyrazol-1-yl-ĸN²)ethanamine-ĸN]zinc(II)

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Intramolecular hydrogen bonding in dichloridobis(3,5-di-tert-butyl-1Hpyrazole-kN²)cobalt(II) as a consequence of ligand steric bulk

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Constructor graph description of the hydrogen-bonding supramolecular assembly in two ionic compounds:2-(pyrazol-1-yl)ethylammonium chloride and diaquadichloridobis(2-hydroxyethylammonium)cobalt(II) dichloride

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(3,5-Dimethyl­pyrazol-1-yl)[5-(3,5-dimethyl­pyrazol-1-ylcarbon­yl)-2-thien­yl]methanone

The title compound, C16H16N4O2S, crystallizes with two symmetry-independent half-mol­ecules in the asymmetric unit. All non-H atoms in each molecule lie in a crystallographic mirror plane. The mol­ecules form sheets in the ac plane, which then form stacks along the b axis. The sheets are connected via π–π stacking inter­actions [centroid–centroid distance between pyrazolato rings = 3.6949 (8) Å]