Computational prediction on the catalytic activity of heterobimetallic complex featuring <scp>MMˊ</scp> triple bond in acetylene cyclotrimerization: Mechanistic study

Zhu

Phys. Chem. Chem. Phys.

et al. 2023

Section: Entropy Correction In the Solution Systemmentioning

confidence: 99%

DFT calculations in solution systems: solvation energy, dispersion energy and entropy

Zhu

Phys. Chem. Chem. Phys.

et al. 2023

“…55−57 However, few theoretical studies focused on the functions and mechanisms of this novel type of heterobimetallic complexes with multiple M−M bonds. 58,59 Very recently, a novel heterobimetallic catalyst was synthesized by Thomas' group using Zr and Co as metal centers. 60−62 In the Zr/Co catalyst, the Zr center combines with two amine ligands, as our conjecture, which may result in a plausible exposed Lewis acidic site.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Later, multiple M–M bonds have been found in a series of heterobimetallic complexes, including V/Fe, , Nb/Fe, Ti/Fe, Ti/Co, and so forth. These multiple-bonded heterobimetallic complexes have shown considerable catalytic activity in C–C coupling, CO 2 activation, reductive coupling, and many other chemical transformations. − However, few theoretical studies focused on the functions and mechanisms of this novel type of heterobimetallic complexes with multiple M–M bonds. , …”

Section: Introductionmentioning

confidence: 99%

Bifunctional Effect of a Triple-Bond Heterobimetallic Zr/Co System for Hydrogen Activation

Jiang

et al. 2021

ACS Catal.

The heterobimetallic systems recently emerged as effective catalysts for hydrogen storage and related chemical transformations. Different from previous Lewis base-transition metal, Lewis acid-transition metal, and frustrated Lewis pair bifunctional catalysis, the function of the heterobimetallic centers in catalysis is still ambiguous. This theoretical study focuses on the Zr/Co complex, aiming to elucidate the important role of the ZrCo triple bond in catalytic H2 activation and hydrogenation. Our results suggest that the Lewis acidic Zr center is stabilized by the ZrCo triple bond. For hydrogen activation, the Zr/Co complex prefers the fac-addition mechanism, in which the cobalt center mainly activates the hydrogen cleavage with the assistance of the Lewis acidic Zr center. The Lewis acidic Zr site is activated by breaking the ZrCo triple bond, promoting the formation of the bridging hydride bond. The bridging hydride is stabilized by the zirconium d orbital to form a 3c–2e bond, resulting in a less nucleophilic bridging hydride. The hydride reactivity and the conjugated effect are two main factors affecting the subsequent hydrogenation. However, the E/Z selectivity is derived from the steric hindrance of the i Pr group. Furthermore, based on the understanding of the bifunctional mode of the heterobimetallic multiple bond, catalysts were designed for divergent E/Z selectivity. These results highlight the importance of the bifunctional function of the heterobimetallic multiple bond, which should be valuable for the rational design of heterobimetallic catalysts.

“…A series of catalytic processes have been successfully implemented with palladium catalysis, which have greatly promoted the development of organic synthesis technology during the recent decades. [1][2][3][4][5][6][7][8] As the field moves forward, the rich organometallic chemistry of palladium is not based entirely on monopalladium complexes. Numbers of examples have been reported for dinuclear palladium catalysts showing distinct advantages over mononuclear ones.…”

Section: Introductionmentioning

confidence: 99%

“…Palladium is a versatile element and common transition metal for catalysis. A series of catalytic processes have been successfully implemented with palladium catalysis, which have greatly promoted the development of organic synthesis technology during the recent decades [1–8] …”

Section: Introductionmentioning

confidence: 99%

DFT Study on Dinuclear Palladium Complex Catalyzed Pyrrole Formation From tert‐Butyl Isocyanide and Alkynes

Lai

2021

ChemCatChem

Density functional theory calculations were carried out to study the mechanisms of Pd-catalyzed reactions of alkynes with tertbutyl isocyanide forming pyrroles. In the case of di-palladium catalysis, the calculations indicated that alkyne insertion, isocyanide insertion, intramolecular cyclization, isocyanide insertion, isomerization and ligand substitution were involved in the mechanism. The intramolecular cyclization process was calculated to be the rate-determining step in the catalytic cycle. The substituent effects on the regioselectivity of reaction were also analyzed. In addition, detailed calculations on monopalladium catalysis showed that the activity of mononuclear catalysis was not as high as that of di-palladium catalysis. These calculation results were in good agreement with the experimental results.