Monodentate Phosphinoamine Nickel Complex Supported on a Metal-Organic Framework for High-Performance Ethylene Dimerization.

Ethylene dimerization is an efficient industrial chemical process to produce 1-butene, with demanding selectivity and activity requirements on new catalytic systems. Herein, a series of monodentate phosphinoamine-nickel complexes immobilized on UiO-66 are described for ethylene dimerization. These catalysts display extensive molecular tunability of the ligand similar to organometallic catalysis, while maintaining the high stability attributed to the metal-organic framework (MOF) scaffold.

N-Alkylation through the Borrowing Hydrogen Pathway Catalyzed by the Metal-Organic Framework-Supported Iridium-Monophosphine Complex.

Further development in the area of medicinal chemistry requires facile and atom-economical C-N bond formation from readily accessible precursors using recyclable and reusable catalysts with low process toxicity. In this work, direct N-alkylation of amines with alcohols is performed with a series of Ir-phosphine-functionalized metal-organic framework (MOF) heterogeneous catalysts. The grafted monophosphine-Ir complexes were studied comprehensively to illustrate the ligand-dependent reactivity.

Ancillary Ligand Effects upon the Photochemistry of Mn(bpy)(CO)X Complexes (X = Br, PhCC).

The photochemistry of two Mn(bpy)(CO)X complexes (X = PhCC, Br) has been studied in the coordinating solvents THF (terahydrofuran) and MeCN (acetonitrile) employing time-resolved infrared spectroscopy. The two complexes are found to exhibit strikingly different photoreactivities and solvent dependencies. In MeCN, photolysis of 1-(CO)(Br) [1 = Mn(bpy)(CO)] affords the ionic complex [1-(MeCN)]Br as a final product.

Palladium-Catalyzed, Multicomponent Approach to β-Lactams via Aryl Halide Carbonylation.

A palladium-catalyzed multicomponent method for the synthesis of β-lactams from imines, aryl halides, and CO has been developed. This transformation proceeds via two tandem catalytic carbonylation reactions mediated by Pd(PBu) and provides a route to prepare these products from five separate reagents. A diverse range of polysubstituted β-lactams can be generated by systematic variation of the substrates.

Synthesis of [Pt(SnBu(t)3)(IBu(t))(μ-H)]2, a Coordinatively Unsaturated Dinuclear Compound which Fragments upon Addition of Small Molecules to Form Mononuclear Pt-Sn Complexes.

The reaction of Pt(COD)2 with one equivalent of tri-tert-butylstannane, Bu(t)3SnH, at room temperature yields Pt(SnBu(t)3)(COD)(H)(3) in quantitative yield. In the presence of excess Bu(t)3SnH, the reaction goes further, yielding the dinuclear bridging stannylene complex [Pt(SnBu(t)3)(μ-SnBu(t)2)(H)2]2 (4). The dinuclear complex 4 reacts rapidly and reversibly with CO to furnish [Pt(SnBu(t)3)(μ-SnBu(t)2)(CO)(H)2]2 (5).

Intramolecular C-C Bond Coupling of Nitriles to a Diimine Ligand in Group 7 Metal Tricarbonyl Complexes.

Dissolution of M(CO)3(Br)(L(Ar)) [L(Ar) = (2,6-Cl2-C6H3-NCMe)2CH2] in either acetonitrile [M = Mn, Re] or benzonitrile (M = Re) results in C-C coupling of the nitrile to the diimine ligand. When reacted with acetonitrile, the intermediate adduct [M(CO)3(NCCH3)(L(Ar))]Br forms and undergoes an intramolecular C-C coupling reaction between the nitrile carbon and the methylene carbon of the β-diimine ligand.

Pendant alkyl and aryl groups on tin control complex geometry and reactivity with H2/D2 in Pt(SnR3)2(CNBu(t))2 (R = Bu(t), Pr(i), Ph, mesityl).

The complex Pt(SnBu(t)3)2(CNBu(t))2(H)2, 1, was obtained from the reaction of Pt(COD)2 and Bu(t)3SnH, followed by addition of CNBu(t). The two hydride ligands in 1 can be eliminated, both in solution and in the solid state, to yield Pt(SnBu(t)3)2(CNBu(t))2, 2. Addition of hydrogen to 2 at room temperature in solution and in the solid state regenerates 1.

Thermal and photochemical reactivity of manganese tricarbonyl and tetracarbonyl complexes with a bulky diazabutadiene ligand.

The manganese tricarbonyl complex fac-Mn(Br)(CO)3((i)Pr2Ph-DAB) (1) [(i)Pr2Ph-DAB = (N,N'-bis(2,6-di-isopropylphenyl)-1,4-diaza-1,3-butadiene)] was synthesized from the reaction of Mn(CO)5Br with the sterically encumbered DAB ligand. Compound 1 exhibits rapid CO release under low power visible light irradiation (560 nm) suggesting its possible use as a photoCORM. The reaction of compound 1 with TlPF6 in the dark afforded the manganese(I) tetracarbonyl complex, [Mn(CO)4((i)Pr2Ph-DAB)][PF6] (2).

Mechanism of CO displacement from an unusually labile rhenium complex: an experimental and theoretical investigation.

The displacement of a CO ligand from an unusually labile rhenium carbonyl complex containing a bidentate carboxyaldehyde pyrrolyl ligand by PPh(3) and pyridine has been investigated. The reaction is found to proceed by an associative, preequilibrium mechanism. Theoretical calculations support the experimental data and provide a complete energetic profile for the reaction.

Ru(x)Pt(y)Sn(z) cluster-derived nanoparticle catalysts: spectroscopic investigation into the nature of active multinuclear single sites.

Cluster-derived Ru(x)Pt(y)Sn(z) nanoparticles are active catalysts in the hydrogenation of nitrobenzene. The nature of the active sites has been elucidated by FTIR spectroscopy using CO and NO as probe molecules. A new metal carbonyl cluster precursor, Pt(2)Ru(2)(SnBu(t)(3))(2)(CO)(9)(μ-H)(2), has been synthesized to obtain a Ru(2)Pt(2)Sn(2)/SiO(2) catalyst, that displayed remarkably high levels of conversion and selectivities compared to other bi-and monometallic analogues.

Reversible hydrogen activation by the Pt complex Pt(Sn(t)Bu3)2(CNtBu)2.

The new platinum complex Pt(Sn(t)Bu(3))(2)(CN(t)Bu)(2)(H)(2), 1, was obtained in 32% yield from the reaction of Pt(COD)(2) with (t)Bu(3)SnH and CN(t)Bu at room temperature. Compound 1 is a mononuclear 18 electron platinum complex in an octahedral geometry which contains two Sn(t)Bu(3)'s, two CN(t)Bu's, and two hydride ligands. The two hydride ligands in 1 can be eliminated, both in solution and in the solid state, to yield the 16 electron complex Pt(Sn(t)Bu(3))(2)(CN(t)Bu)(2), 2.