Experimental and computational studies of ruthenium complexes bearing Z-acceptor aluminum-based phosphine pincer ligands

Connie J. Isaac; Cameron I. Wilson; Arron L. Burnage; Fedor M. Miloserdov; Mary F. Mahon; Stuart A. Macgregor; Michael K. Whittlesey

doi:10.1021/acs.inorgchem.2c03665

Experimental and computational studies of ruthenium complexes bearing Z-acceptor aluminum-based phosphine pincer ligands

Connie J. Isaac, Cameron I. Wilson, Arron L. Burnage, Fedor M. Miloserdov, Mary F. Mahon, Stuart A. Macgregor^*, Michael K. Whittlesey^*

^*Corresponding author for this work

School of Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Reaction of [Ru(C₆H₄PPh₂)₂(Ph₂PC₆H₄AlMe(THF))H] with CO results in clean conversion to the Ru−Al heterobimetallic complex [Ru(AlMePhos)(CO)₃] (1), where AlMePhos is the novel P–Al(Me)–P pincer ligand (o-Ph₂PC₆H₄)₂AlMe. Under photolytic conditions, 1 reacts with H₂ to give [Ru(AlMePhos)(CO)₂(μ-H)H] (2) that is characterized by multinuclear NMR and IR spectroscopies. DFT calculations indicate that 2 features one terminal and one bridging hydride that are respectively anti and syn to the AlMe group. Calculations also define a mechanism for H₂ addition to 1 and predict facile hydride exchange in 2 that is also observed experimentally. Reaction of 1 with B(C₆F₅)₃ results in Me abstraction to form the ion pair [Ru(AlPhos)(CO)₃][MeB(C₆F₅)₃] (4) featuring a cationic [(o-Ph₂PC₆H₄)₂Al]⁺ ligand, [AlPhos]⁺. The Ru–Al distance in 4 (2.5334(16) Å) is significantly shorter than that in 1 (2.6578(6) Å), consistent with an enhanced Lewis acidity of the [AlPhos]⁺ ligand. This is corroborated by a blue shift in both the observed and computed νCO stretching frequencies upon Me abstraction. Electronic structure analyses (QTAIM and EDA-ETS) comparing 1, 4, and the previously reported [Ru(ZnPhos)(CO)₃] analogue (ZnPhos = (o-Ph₂PC₆H₄)₂Zn) indicate that the Lewis acidity of these pincer ligands increases along the series ZnPhos < AlMePhos < [AlPhos]⁺.

Original language	English
Pages (from-to)	20690-20698
Number of pages	9
Journal	Inorganic Chemistry
Volume	61
Issue number	50
Early online date	7 Dec 2022
DOIs	https://doi.org/10.1021/acs.inorgchem.2c03665
Publication status	Published - 19 Dec 2022

Access to Document

10.1021/acs.inorgchem.2c03665Licence: CC BY

Isaac_2022_IC_Experimental-ruthenium-complexes-phosphine-pincer-ligands_CC
© 2022 The Authors. This publication is licensed under CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/).
Final published version, 2.91 MBLicence: CC BY

CCDC 2182238 & 2182239: Experimental Crystal Structure Determination
Isaac, C. J. (Creator), Wilson, C. I. (Creator), Burnage, A. L. (Creator), Miloserdov, F. M. (Creator), Mahon, M. F. (Creator), Macgregor, S. A. (Creator) & Whittlesey, M. K. (Creator), Cambridge Crystallographic Data Centre, 2022
DOI: 10.5517/ccdc.csd.cc2c7ss6, https://dx.doi.org/10.5517/ccdc.csd.cc2c7st7
Dataset

Cite this

@article{3e7a99c1061644e587efbcb4a3bc0af4,

title = "Experimental and computational studies of ruthenium complexes bearing Z-acceptor aluminum-based phosphine pincer ligands",

abstract = "Reaction of [Ru(C6H4PPh2)2(Ph2PC6H4AlMe(THF))H] with CO results in clean conversion to the Ru−Al heterobimetallic complex [Ru(AlMePhos)(CO)3] (1), where AlMePhos is the novel P–Al(Me)–P pincer ligand (o-Ph2PC6H4)2AlMe. Under photolytic conditions, 1 reacts with H2 to give [Ru(AlMePhos)(CO)2(μ-H)H] (2) that is characterized by multinuclear NMR and IR spectroscopies. DFT calculations indicate that 2 features one terminal and one bridging hydride that are respectively anti and syn to the AlMe group. Calculations also define a mechanism for H2 addition to 1 and predict facile hydride exchange in 2 that is also observed experimentally. Reaction of 1 with B(C6F5)3 results in Me abstraction to form the ion pair [Ru(AlPhos)(CO)3][MeB(C6F5)3] (4) featuring a cationic [(o-Ph2PC6H4)2Al]+ ligand, [AlPhos]+. The Ru–Al distance in 4 (2.5334(16) {\AA}) is significantly shorter than that in 1 (2.6578(6) {\AA}), consistent with an enhanced Lewis acidity of the [AlPhos]+ ligand. This is corroborated by a blue shift in both the observed and computed νCO stretching frequencies upon Me abstraction. Electronic structure analyses (QTAIM and EDA-ETS) comparing 1, 4, and the previously reported [Ru(ZnPhos)(CO)3] analogue (ZnPhos = (o-Ph2PC6H4)2Zn) indicate that the Lewis acidity of these pincer ligands increases along the series ZnPhos < AlMePhos < [AlPhos]+.",

author = "Isaac, {Connie J.} and Wilson, {Cameron I.} and Burnage, {Arron L.} and Miloserdov, {Fedor M.} and Mahon, {Mary F.} and Macgregor, {Stuart A.} and Whittlesey, {Michael K.}",

note = "Funding: This project has received funding from the European Union{\textquoteright}s Horizon 2020 research and innovation programme under the Marie Sk{\l}odowska-Curie grant agreement no. 792674 (FMM) and EPSRC (DTP studentships to C.J.I. and A.L.B.).",

year = "2022",

month = dec,

day = "19",

doi = "10.1021/acs.inorgchem.2c03665",

language = "English",

volume = "61",

pages = "20690--20698",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society (ACS)",

number = "50",

}

TY - JOUR

T1 - Experimental and computational studies of ruthenium complexes bearing Z-acceptor aluminum-based phosphine pincer ligands

AU - Isaac, Connie J.

AU - Wilson, Cameron I.

AU - Burnage, Arron L.

AU - Miloserdov, Fedor M.

AU - Mahon, Mary F.

AU - Macgregor, Stuart A.

AU - Whittlesey, Michael K.

N1 - Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 792674 (FMM) and EPSRC (DTP studentships to C.J.I. and A.L.B.).

PY - 2022/12/19

Y1 - 2022/12/19

N2 - Reaction of [Ru(C6H4PPh2)2(Ph2PC6H4AlMe(THF))H] with CO results in clean conversion to the Ru−Al heterobimetallic complex [Ru(AlMePhos)(CO)3] (1), where AlMePhos is the novel P–Al(Me)–P pincer ligand (o-Ph2PC6H4)2AlMe. Under photolytic conditions, 1 reacts with H2 to give [Ru(AlMePhos)(CO)2(μ-H)H] (2) that is characterized by multinuclear NMR and IR spectroscopies. DFT calculations indicate that 2 features one terminal and one bridging hydride that are respectively anti and syn to the AlMe group. Calculations also define a mechanism for H2 addition to 1 and predict facile hydride exchange in 2 that is also observed experimentally. Reaction of 1 with B(C6F5)3 results in Me abstraction to form the ion pair [Ru(AlPhos)(CO)3][MeB(C6F5)3] (4) featuring a cationic [(o-Ph2PC6H4)2Al]+ ligand, [AlPhos]+. The Ru–Al distance in 4 (2.5334(16) Å) is significantly shorter than that in 1 (2.6578(6) Å), consistent with an enhanced Lewis acidity of the [AlPhos]+ ligand. This is corroborated by a blue shift in both the observed and computed νCO stretching frequencies upon Me abstraction. Electronic structure analyses (QTAIM and EDA-ETS) comparing 1, 4, and the previously reported [Ru(ZnPhos)(CO)3] analogue (ZnPhos = (o-Ph2PC6H4)2Zn) indicate that the Lewis acidity of these pincer ligands increases along the series ZnPhos < AlMePhos < [AlPhos]+.

AB - Reaction of [Ru(C6H4PPh2)2(Ph2PC6H4AlMe(THF))H] with CO results in clean conversion to the Ru−Al heterobimetallic complex [Ru(AlMePhos)(CO)3] (1), where AlMePhos is the novel P–Al(Me)–P pincer ligand (o-Ph2PC6H4)2AlMe. Under photolytic conditions, 1 reacts with H2 to give [Ru(AlMePhos)(CO)2(μ-H)H] (2) that is characterized by multinuclear NMR and IR spectroscopies. DFT calculations indicate that 2 features one terminal and one bridging hydride that are respectively anti and syn to the AlMe group. Calculations also define a mechanism for H2 addition to 1 and predict facile hydride exchange in 2 that is also observed experimentally. Reaction of 1 with B(C6F5)3 results in Me abstraction to form the ion pair [Ru(AlPhos)(CO)3][MeB(C6F5)3] (4) featuring a cationic [(o-Ph2PC6H4)2Al]+ ligand, [AlPhos]+. The Ru–Al distance in 4 (2.5334(16) Å) is significantly shorter than that in 1 (2.6578(6) Å), consistent with an enhanced Lewis acidity of the [AlPhos]+ ligand. This is corroborated by a blue shift in both the observed and computed νCO stretching frequencies upon Me abstraction. Electronic structure analyses (QTAIM and EDA-ETS) comparing 1, 4, and the previously reported [Ru(ZnPhos)(CO)3] analogue (ZnPhos = (o-Ph2PC6H4)2Zn) indicate that the Lewis acidity of these pincer ligands increases along the series ZnPhos < AlMePhos < [AlPhos]+.

U2 - 10.1021/acs.inorgchem.2c03665

DO - 10.1021/acs.inorgchem.2c03665

M3 - Article

C2 - 36475641

SN - 0020-1669

VL - 61

SP - 20690

EP - 20698

JO - Inorganic Chemistry

JF - Inorganic Chemistry

IS - 50

ER -

Experimental and computational studies of ruthenium complexes bearing Z-acceptor aluminum-based phosphine pincer ligands

Abstract

Access to Document

Fingerprint

Datasets

CCDC 2182238 & 2182239: Experimental Crystal Structure Determination

Cite this