Carbon Monoxide Assisted Self‐Assembled Platinum Nanoparticles for Catalytic Asymmetric Hydrogenation

Abstract

Pt NPs CO‐operate: Pt nanorods (Pt NRs) have been developed by the self‐assembly of uniformly distributed small Pt nanoparticles (Pt NPs, 1.8–2.4 nm), obtained from [Pt(cod)Cl2] (cod=1,5‐cyclooctadiene) in the presence of CO in non‐aqueous medium. As‐synthesized non‐supported Pt NRs catalyze the asymmetric hydrogenation of methyl pyruvate and acetophenone to (R)‐methyl lactate and (R)‐1‐phenyl ethanol, respectively (see scheme).

Effect of Ni, Pd, and Pt Nanoparticle Dispersion on Thick Films of TiO2 Nanotubes for Hydrogen Sensing: TEM and XPS Studies

“…Each of the composites exhibit the existence of agglomerated metal NPs as spheres that are present over the bundles of TiO 2 NTs. There is a significant reduction in the wall thickness of the TiO 2 NTs to about 3–4 nm and the inner tubular diameter to about 15–20 nm, as seen from the transmission electron microscopy (TEM) image displayed in Figure a . The diameter of the Pt and Pd nanoparticles was about 20 nm (Figure c,e).…”

“…There is a significant reduction in the wall thickness of the TiO 2 NTs to about 3−4 nm and the inner tubular diameter to about 15−20 nm, as seen from the transmission electron microscopy (TEM) image displayed in Figure 5a. 16 The diameter of the Pt and Pd nanoparticles was about 20 nm (Figure 5c,e). The dark and bright field images of pristine TiO 2 NTs and nanocomposites clearly indicate that the metal nanoparticles are present at the periphery of the tube walls (Figure 5b,d,f).…”

“…XRD data from Table affirms the face-centered cubic (FCC) structure of Pt, Pd, and Ni NPs dispersed on TiO 2 NTs [JCPDS Nos. 87-0646, 89-4897 and 04-0850], respectively. − …”

Chiral metal nanoparticle-catalyzed asymmetric C–C bond formation reactions

“…37,38 Although the first Oritotype reaction was reported more than 30 years ago, this type of reaction is still being studied. [39][40][41][42][43] Recently, studies were carried out to improve the catalyst system [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] and to reveal its detailed mechanism. [62][63][64][65][66][67] It is generally accepted that the chemisorption layer, through the formation of individual 1 : 1 diastereomeric complexes from substrates and chiral modifiers, is the key to inducing chirality in this reaction.…”