Structure and dynamics of catalytically competent but labile paramagnetic metal-hydrides: the Ti(iii)-H in homogeneous olefin polymerization

Abstract

Metal hydride complexes find widespread application in catalysis and their properties are often understood on the basis of the available crystal structures. However, some catalytically relevant metal hydrides are only...

Porous oligomeric materials synthesised using a new, highly active precatalyst based on ruthenium(iii) and 2-phenylpyridine

“…1). [9][10][11][12] Ruthenium-based catalysts are mostly used in olefin metathesis, e.g., Grubbs catalysts. 13 To date, few scientific publications relate to ruthenium precatalysts used in olefin polymerization.…”

Synthesis and Tuning of Gold Nanoparticles Supported on Polymorphic Semicrystalline Nanoporous Polymer for Catalytic Aerobic Oxidation of Alcohols

“…[13] Microencapsulation of naked AuNPs in covalently crosslinked polystyrene [8] yielded one of the most efficient gold nanocatalysts suitable in a wide range of organic transformations such as aerobic oxidation of alcohols, direct synthesis of esters, amides via aerobic oxidative reaction couplings. [14] In previous studies, we investigated the catalytic performance of AuNPs embedded in a nanoporous crystalline polymer matrix consisting of syndiotactic polystyrene (sPS) [15][16][17][18][19][20] or of multiblock copolymer with 1,3-butadiene, i. e., syndiotactic polystyrene-co-cis-1,4-polybutadiene (sPSB). [5,9,[21][22][23][24][25] These gold catalysts are efficient and selective in the aerobic oxidation of alcohols [9,23,25] or aldehydes, [21] direct oxidative esterification of alcohols, [21,23,25] reduction of nitroarenes to azobenzenes, oxyazobenzenes or anilines, [22] and the coupling of phenylacetylenes with anilines to ketimines.…”

“…[29] Interestingly both polar and non-polar organic solvents such as methanol, dimethylformamide, dimethylacetamide, acetone, acetonitrile, chloroform, tetrahydrofuran or toluene readily permeate the channels and cavities of the crystalline polymer phase to produce a fast exchange of small molecules in the crystalline phases. [5,9,[21][22][23][24][25]30] Organic solvents such as toluene, tetrahydrofuran, chloroform, dichloromethane and dimethylformamide [15][16][17][18][19][20] act as swelling agents of the sPS and sPSB polymer matrix, thus, facilitating the access to the catalytic sites and thus their reactivity. [24] The efficient aerobic oxidation of alcohols [9,21,23,25] in the presence of inorganic bases and the nitroarene reduction in the presence of sodium borohydride suggest that simple inorganic compounds such as metal hydroxides and hydrides can be conveyed throughout porous polystyrenic support when appropriate solvents and experimental conditions are employed.…”

“…In previous studies, we investigated the catalytic performance of AuNPs embedded in a nanoporous crystalline polymer matrix consisting of syndiotactic polystyrene (sPS) [15–20] or of multiblock copolymer with 1,3‐butadiene, i. e., syndiotactic polystyrene‐ co ‐ cis ‐1,4‐polybutadiene (sPSB) [5,9,21–25] . These gold catalysts are efficient and selective in the aerobic oxidation of alcohols [9,23,25] or aldehydes, [21] direct oxidative esterification of alcohols, [21,23,25] reduction of nitroarenes to azobenzenes, oxyazobenzenes or anilines, [22] and the coupling of phenylacetylenes with anilines to ketimines [24] .…”

Synthesis, structure and functions of discrete titanium-based multinuclear architectures

“…Overall, these Ti(III)-based complexes used on this purpose are dominated by mono-or bimetallic complexes. [37,38] All these domains drive the design, construction and study of molecular titanium-based multinuclear architectures. Nowadays, the rational synthesis of such architectures remains challenging because of the very specific coordination chemistry of titanium, especially at the most widespread oxidation state +IV.…”