Impact of Halide (Cl vs I) Identity on the Preferred Positioning of Substituents between Al and M (M = Co, Rh, Ir) in PAlP Pincer Complexes
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Protolysis of AlMe 3 or AlEt 3 with 2-diisopropylphosphinopyrrole ( 1 ) resulted in alane/bis(phosphine) pincer ligands containing two flanking phosphines and a central Al–Me ( 2-Me ), Al–Et ( 2-Et ) unit. Reactions of 2-Me with [(COD)MI] 2 (COD = 1,5-cyclooctadiene; M = Rh or Ir) in the presence of pyridine produced pincer complexes ( 3–Rh–I and 3–Ir–I ) with M supported by the PAlP tridentate ligand, and pyridine, methyl, and iodide as monodentate ligands for Al or M. The analogous reaction of 2-Et with [(COD)MI] 2 and pyridine resulted in the formation of the analogous compounds 4–Rh–I and 4–Ir–I with hydride in place of methyl. DFT calculations were used to analyze the thermodynamic preferences for the positioning of pyridine, methyl or hydride, and the halide (chloride or iodide) on M vs Al. Cobalt was included with Rh and Ir among M for the purposes of DFT calculations. Theoretical studies suggested that different isomers are preferred for the iodide complexes (M–I and Al–Py) than for the chloride ones (M–py and Al–Cl, previously reported for Rh and Ir). X-ray structural study of 3–Rh–I and analysis of the 1 H NMR data of the Rh and Ir compounds in benzene corroborated these predictions.
Source: Organometallics
Institutions: Texas A&M University, Mahidol University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4405925799