Dehydrogenation of formic acid using iridium-NSi species as catalyst precursors

Abstract

Using a low loading of the iridium(III) complexes [Ir(CF3SO3)(κ2-NSiiPr)2] (1) (NSiiPr = (4-methylpyridin-2-iloxy)diisopropylsilyl and [{Ir(κ2-NSiMe)2}2(µ-CF3SO3)2] (2) (NSiMe = (4-methylpyridin-2-iloxy)dimethylsilyl) in presence of Et3N, it has been possible to achieve the...

Synthesis and Characterization of Ir-(κ2-NSi) Species Active toward the Solventless Hydrolysis of HSiMe(OSiMe3)2

“…Indeed, iridium complexes of the type Ir-(κ 2 -NSi Me2 ) 2 (NSi Me2 = 4-methylpyridin-2-yloxy-dimethylsilyl) are more active catalysts for the reduction of CO 2 with silanes than the corresponding Ir-{ fac -κ 3 -( N,Si,N )-NSiN} species . However, the Ir–Si bond in Ir-(κ 2 -NSi Me2 ) 2 species is not stable under protic conditions . Therefore, we decided to protect the Ir–Si bond with two bulky tertbutyl substituents at the silicon atom of the κ 2 -NSi tBu2 ligand …”

Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance

“…The systems based on 4 and 5 show the decomposition of the catalyst to give iridium nanoparticles, in a similar fashion to that previously observed for the related Ir-(κ 2 -NSi Me 2 ) 2 species. 16 Conversely, the formation of iridium nanoparticles was not observed when using 2 or 3 . These results show that the use of coordinatively saturated catalyst precursors prevents the reduction of iridium( iii ) and encouraged us to study the performance of 3 as catalyst for FADH.…”

“…In this regard, it should be mentioned that examples of catalytic systems effective for catalytic FADH under neat conditions are scarce. 16,18,19…”

A Low-Coordinate Iridium Complex with a Donor-Flexible O,N-Ligand for Highly Efficient Formic Acid Dehydrogenation

“…Iridium complex II and ruthenium complex III reach higher turnover numbers (TONs); however, they are built from precious metals . Further work confirmed the potential of precious metals for high catalytic activity and stability, − which is attractive for long-term use subject to proper catalyst recycling. The implementation of such catalytic systems is, however, often hampered by the requirement of sophisticated and expensive ligands to impart high catalytic activity …”