ChemInform Abstract: STEREOSELECTIVE OXIDATIVE ADDITION OF HYDROGEN TO IRIDIUM(I) COMPLEXES. KINETIC CONTROL BASED ON LIGAND ELECTRONIC EFFECTS

1985 ◽  
Vol 16 (38) ◽  
Author(s):  
C. E. JOHNSON ◽  
R. EISENBERG
2021 ◽  
Author(s):  
Michael R. Hurst ◽  
Lev N. Zakharov ◽  
Amanda K. Cook

Mechanistic studies reveal the rate law, an H/D KIE, and that the silane’s electronics impact the thermodynamic and kinetic energetics of the oxidative addition reaction. These electronic effects are relevant in the hydrosilylation of alkynes.


1984 ◽  
Vol 62 (3) ◽  
pp. 534-539 ◽  
Author(s):  
Erwin Buncel ◽  
Suresh Kumar Murarka ◽  
Albert Richard Norris

The reactions of 1-phenyl-2,4,6-trinitrobenzene (4) with methoxide and phenoxide ions in DMSO and DMSO–methanol solutions have been investigated. MeO− gives rise to a 1,3 adduct through kinetic control and a 1,1 adduct through thermodynamic control. These processes persist also in the reaction of 4 with potassium phenoxide in DMSO–methanol. However, reaction of 4 with potassium phenoxide in DMSO gives rise to a 1,3 adduct as the only observed species in which phenoxide is bonded to the nitroaromatic moiety via the para phenoxy carbon, in accord with previous observations on the ambident reactivity of phenoxide ion. The results are considered in terms of various steric and electronic effects and it is concluded that F-strain, relief of steric compression, and delocalizability considerations play dominant roles in accounting for the observed reaction course.


2011 ◽  
Vol 30 (3) ◽  
pp. 603-610 ◽  
Author(s):  
Wen Zhou ◽  
Liming Tang ◽  
Brian O. Patrick ◽  
Kevin M. Smith

1983 ◽  
Vol 105 (26) ◽  
pp. 7772-7774 ◽  
Author(s):  
Curtis E. Johnson ◽  
Barbara J. Fisher ◽  
Richard Eisenberg

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 373
Author(s):  
Marek Freindorf ◽  
Seth Yannacone ◽  
Vytor Oliveira ◽  
Niraj Verma ◽  
Elfi Kraka

We systematically investigated iodine–metal and iodine–iodine bonding in van Koten’s pincer complex and 19 modifications changing substituents and/or the transition metal with a PBE0–D3(BJ)/aug–cc–pVTZ/PP(M,I) model chemistry. As a novel tool for the quantitative assessment of the iodine–metal and iodine–iodine bond strength in these complexes we used the local mode analysis, originally introduced by Konkoli and Cremer, complemented with NBO and Bader’s QTAIM analyses. Our study reveals the major electronic effects in the catalytic activity of the M–I–I non-classical three-center bond of the pincer complex, which is involved in the oxidative addition of molecular iodine I2 to the metal center. According to our investigations the charge transfer from the metal to the σ* antibonding orbital of the I–I bond changes the 3c–4e character of the M–I–I three-center bond, which leads to weakening of the iodine I–I bond and strengthening of the metal–iodine M–I bond, facilitating in this way the oxidative addition of I2 to the metal. The charge transfer can be systematically modified by substitution at different places of the pincer complex and by different transition metals, changing the strength of both the M–I and the I2 bonds. We also modeled for the original pincer complex how solvents with different polarity influence the 3c–4e character of the M–I–I bond. Our results provide new guidelines for the design of pincer complexes with specific iodine–metal bond strengths and introduce the local vibrational mode analysis as an efficient tool to assess the bond strength in complexes.


2019 ◽  
Vol 220 ◽  
pp. 386-403 ◽  
Author(s):  
Raed A. Alharis ◽  
Claire L. McMullin ◽  
David L. Davies ◽  
Kuldip Singh ◽  
Stuart A. Macgregor

C–H activation processes may show contradictory substituent effects depending on the reaction conditions: under kinetic control ligands with electron-releasing substituents are favoured, whereas the opposite trend is seen under thermodynamic control.


2018 ◽  
Vol 47 (8) ◽  
pp. 2662-2669 ◽  
Author(s):  
H.-L. Qin ◽  
J. Leng ◽  
W. Zhang ◽  
E. A. B. Kantchev

DFT calculations confirmed that the rearrangement of a PCP-Rh-H pincer to a CCP-Rh-phosphane pincer occured by C–P oxidative addition (ΔG‡ = 29.5 kcal mol−1, rate-determining step), followed by P–H reductive elimination (ΔG‡ = 4.8 kcal mol−1).


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