(Dicyclopentadiene) platinum(II) dichloride: An efficient catalyst for the hydrosilylation reaction between alkenes and triethoxysilane

Revisiting carboxylic group functionalization of silica sol-gel materials

The carboxylic chemical group is a ubiquitous moiety present in amino acids, a ligand for transition metals, a colloidal stabilizer, and a weak acidic ion-exchanger in polymeric resins and given this property, it is attractive for responsive materials or nanopore-based gating applications. As the number of uses increases, subtle requirements are imposed on this molecular group when anchored to various platforms for the functioning of an integrated chemical system. In this context, silica stands as an inert and multipurpose platform that enables the anchoring of multiple chemical entities combined through several orthogonal synthesis methods on the interface. Surface chemical modification relies on the use of organoalkoxysilanes that must meet the demand of tuned chemical properties; this, in turn, urges for innovative approaches for having an improved, but simple, organic toolbox. Starting from commonly available molecular precursors, several approaches have emerged: hydrosilylation, click thiol-ene additions, the use of carbodiimides or the reaction between cyclic anhydrides and anchored amines. In this review, we analyze the importance of the COOH groups in the area of materials science and the commercial availability of COOH-based silanes and present new approaches for obtaining COOH-based organoalkoxide precursors. Undoubtedly, this will attract widespread interest for the ultimate design of highly integrated chemical platforms.

Borane-Protecting Strategy for Hydrosilylation of Phosphorus-Containing Olefins

Ir-catalyzed hydrosilylation of the alkenyl phosphine borane complex 1 was achieved to give the corresponding products 2. Because the phosphino group coordinates with metals and is unstable under aerobic conditions, the formation of the corresponding borane adduct was effective not only to promote the target hydrosilylation but also to keep 1 stable under aerobic conditions. The removal of coordinated borane from 2 was readily performed with the treatment by 1,4-diazabicyclo[2.2.2]octane to apply to further transformations. The immobilization and following deprotection of 2 on the surface of mesoporous silica were also examined.

Platinum on 2-aminoethanethiol functionalized MIL-101 as a catalyst for alkene hydrosilylation

Hydrosilylation is one of the largest-scale applications for homogeneous catalysis and is widely used to enable the commercial manufacture of silicon products. In this paper, a bifunctional heterogeneous catalyst, Pt^δ+/AET-MIL-101 (AET = 2-aminoethanethiol) with a partially positively charged Pt^δ+ electronic structure is reported, which was successfully prepared using post-synthesis modification with AET and a platinum precursor. The catalysts were characterized using X-ray diffraction (XRD), nitrogen (N₂) adsorption–desorption, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques which showed that the synergy of AET-MIL-101 provides a good dispersion of Pt^δ+ in the channels, which can efficiently catalyze the hydrosilylation reaction with almost complete conversion and produce a unique adduct. In addition, the synthetic heterogeneous catalyst Pt^δ+/AET-MIL-101 achieves reasonable use of Pt in terms of number cycles and atomic utilization efficiency, indicating the potential to achieve a green hydrosilylation industry.

Pt^δ+ was uniformly dispersed in AET-MIL-101 as a highly efficient catalyst for a catalytic hydrosilylation reaction.

Charge-Storage Aromatic Amino Compounds for Nonvolatile Organic Transistor Memory Devices

Here, charge-storage nonvolatile organic field-effect transistor (OFET) memory devices based on interfacial self-assembled molecules are proposed. The functional molecules contain various aromatic amino moieties (N-phenyl-N-pyridyl amino- (PyPN), N-phenyl amino- (PN), and N,N-diphenyl amino- (DPN)) which are linked by a propyl chain to a triethoxysilyl anchor group and act as the interface modifiers and the charge-storage elements. The PyPN-containing pentacene-based memory device (denoted as PyPN device) presents the memory window of 48.43 V, while PN and DPN devices show the memory windows of 24.88 and 8.34 V, respectively. The memory characteristic of the PyPN device can remain stable along with 150 continuous write-read-erase-read cycles. The morphology analysis confirms that three interfacial layers show aggregation due to the N atomic self-catalysis and hydrogen bonding effects. The large aggregate-covered PyPN layer has the full contact area with the pentacene molecules, leading to the high memory performance. In addition, the energy level matching between PyPN molecules and pentacene creates the smallest tunneling barrier and facilitates the injection of the hole carriers from pentacene to the PyPN layer. The experimental memory characteristics are well in agreement with the computational calculation.