TY - JOUR
T1 - Experimental and Computational Studies of Phosphine Ligand Displacement in Iridium-Pincer Complexes Employing Pyridine or Acetonitrile
AU - Shafiei-Haghighi, Sara
AU - Brar, Aneelman
AU - Unruh, Daniel K.
AU - Cozzolino, Anthony F.
AU - Findlater, Michael
N1 - Funding Information:
The authors gratefully acknowledge the National Science Foundation (CHE-1554906) for financial support of this work and the High Performance Computing Center (HPCC) at Texas Tech University for providing HPC resources that have contributed to the research results reported within this paper.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/10/12
Y1 - 2020/10/12
N2 - This report describes the synthesis, characterization, and ligand exchange studies of iridium-based, pincer complexes. (tBuPOCOP)Ir(PPh3) (tBuPOCOP = 2,6-bis(di-tert-butylphosphonito)benzene) serves as a convenient source of the latent Ir(I), 14-electron species [(tBuPOCOP)Ir] and is susceptible to ligand exchange chemistry; reactions with acetonitrile and pyridine afford the corresponding (tBuPOCOP)Ir(NCMe) (2) and (tBuPOCOP)Ir(Py) (3) complexes, respectively. Varying concentrations of both pyridine and acetonitrile, the kinetic and thermodynamic parameters of the ligand exchange process between (tBuPOCOP)Ir(PPh3) and L (L = MeCN or pyridine) were determined by employing NMR, UV-vis spectroscopy, and density functional theory (DFT) calculations to measure the relevant equilibria. A discussion of these results allows us to address whether phosphine displacement occurs via an associative or a dissociative pathway.
AB - This report describes the synthesis, characterization, and ligand exchange studies of iridium-based, pincer complexes. (tBuPOCOP)Ir(PPh3) (tBuPOCOP = 2,6-bis(di-tert-butylphosphonito)benzene) serves as a convenient source of the latent Ir(I), 14-electron species [(tBuPOCOP)Ir] and is susceptible to ligand exchange chemistry; reactions with acetonitrile and pyridine afford the corresponding (tBuPOCOP)Ir(NCMe) (2) and (tBuPOCOP)Ir(Py) (3) complexes, respectively. Varying concentrations of both pyridine and acetonitrile, the kinetic and thermodynamic parameters of the ligand exchange process between (tBuPOCOP)Ir(PPh3) and L (L = MeCN or pyridine) were determined by employing NMR, UV-vis spectroscopy, and density functional theory (DFT) calculations to measure the relevant equilibria. A discussion of these results allows us to address whether phosphine displacement occurs via an associative or a dissociative pathway.
UR - http://www.scopus.com/inward/record.url?scp=85094625517&partnerID=8YFLogxK
U2 - 10.1021/acs.organomet.0c00202
DO - 10.1021/acs.organomet.0c00202
M3 - Article
AN - SCOPUS:85094625517
VL - 39
SP - 3461
EP - 3468
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 19
ER -