TY  - JOUR
AU  - Ninković, Dragan
AU  - Moncho, Salvador
AU  - Petrović, Predrag
AU  - Hall, Michael B.
AU  - Zarić, Snežana D.
AU  - Brothers, Edward N.
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6196
AB  - We present results for a series of complexes derived from a titanium complex capable of activating C–H bonds under mild conditions (PNP)Ti═CHtBu(CH2tBu), where PNP = N[2-PiPr2-4-methylphenyl]2–. In addition to the initial activation of methane, a tautomerization reaction to a terminal methylidene is also explored due to methylidene’s potential use as a synthetic starting point. Analogous complexes with other low-cost 3d transition metals were studied, such as scandium, titanium, vanadium, and chromium as both isoelectronic and isocharged complexes. Our results predict that V(IV) and V(V) complexes are promising for methane C–H bond activation. The V(V) complex has a low rate-determining barrier for methane activation, specifically 16.6 kcal/mol, which is approximately 12 kcal/mol less than that for the Ti complex, as well as having a moderate tautomerization barrier of 29.8 kcal/mol, while the V(IV) complex has a methane activation barrier of 19.0 kcal/mol and a tautomerization barrier of 31.1 kcal/mol. Scandium and chromium complexes are much poorer for C–H bond activation; scandium has very high barriers, while chromium strongly overstabilizes the alkylidene intermediate, potentially stopping the further reaction. In addition to the original PNP ligand, some of the most promising ligands from a previous work were tested, although (as shown previously) modification of the ligand does not typically have large effects on the activity of the system. Our best ligand modification improves the performance of the V(V) complex via the substitution of the nitrogen in PNP by phosphorus, which reduces the tautomerization barrier by 5 to 24.4 kcal/mol.
PB  - American Chemical Society
T2  - Inorganic Chemistry
T1  - Improving a Methane C–H Activation Complex by Metal and Ligand Alterations from Computational Results
VL  - 62
IS  - 13
SP  - 5058
EP  - 5066
DO  - 10.1021/acs.inorgchem.2c03342
ER  - 

@article{
author = "Ninković, Dragan and Moncho, Salvador and Petrović, Predrag and Hall, Michael B. and Zarić, Snežana D. and Brothers, Edward N.",
year = "2023",
abstract = "We present results for a series of complexes derived from a titanium complex capable of activating C–H bonds under mild conditions (PNP)Ti═CHtBu(CH2tBu), where PNP = N[2-PiPr2-4-methylphenyl]2–. In addition to the initial activation of methane, a tautomerization reaction to a terminal methylidene is also explored due to methylidene’s potential use as a synthetic starting point. Analogous complexes with other low-cost 3d transition metals were studied, such as scandium, titanium, vanadium, and chromium as both isoelectronic and isocharged complexes. Our results predict that V(IV) and V(V) complexes are promising for methane C–H bond activation. The V(V) complex has a low rate-determining barrier for methane activation, specifically 16.6 kcal/mol, which is approximately 12 kcal/mol less than that for the Ti complex, as well as having a moderate tautomerization barrier of 29.8 kcal/mol, while the V(IV) complex has a methane activation barrier of 19.0 kcal/mol and a tautomerization barrier of 31.1 kcal/mol. Scandium and chromium complexes are much poorer for C–H bond activation; scandium has very high barriers, while chromium strongly overstabilizes the alkylidene intermediate, potentially stopping the further reaction. In addition to the original PNP ligand, some of the most promising ligands from a previous work were tested, although (as shown previously) modification of the ligand does not typically have large effects on the activity of the system. Our best ligand modification improves the performance of the V(V) complex via the substitution of the nitrogen in PNP by phosphorus, which reduces the tautomerization barrier by 5 to 24.4 kcal/mol.",
publisher = "American Chemical Society",
journal = "Inorganic Chemistry",
title = "Improving a Methane C–H Activation Complex by Metal and Ligand Alterations from Computational Results",
volume = "62",
number = "13",
pages = "5058-5066",
doi = "10.1021/acs.inorgchem.2c03342"
}

Ninković, D., Moncho, S., Petrović, P., Hall, M. B., Zarić, S. D.,& Brothers, E. N.. (2023). Improving a Methane C–H Activation Complex by Metal and Ligand Alterations from Computational Results. in Inorganic Chemistry
American Chemical Society., 62(13), 5058-5066.
https://doi.org/10.1021/acs.inorgchem.2c03342

Ninković D, Moncho S, Petrović P, Hall MB, Zarić SD, Brothers EN. Improving a Methane C–H Activation Complex by Metal and Ligand Alterations from Computational Results. in Inorganic Chemistry. 2023;62(13):5058-5066.
doi:10.1021/acs.inorgchem.2c03342 .

Ninković, Dragan, Moncho, Salvador, Petrović, Predrag, Hall, Michael B., Zarić, Snežana D., Brothers, Edward N., "Improving a Methane C–H Activation Complex by Metal and Ligand Alterations from Computational Results" in Inorganic Chemistry, 62, no. 13 (2023):5058-5066,
https://doi.org/10.1021/acs.inorgchem.2c03342 . .