Development and Catalysis of Iridium NCOP Pincer-ligand Systems (2015)

Undergraduates: Christopher Sato, Matthew Kita

Faculty Advisor: Alexander Miller
Department: Chemistry

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Herin we report the synthesis, characterization, and preliminary catalytic data of (RNCOPiPr) iridium pincer complexes, where NCOPiPr is amino-methyldiisopropylphosphinitobenzene with R = morpholine or diethyl. These (RNCOPiPr) ligands have been previously reported for the synthesis of organometallic Ni complexes, but have not been used to form iridium complexes. Meridonally coordinating tridentate pincer ligands represent an extensive class of ligands for iridium. Representative examples include PNP, PCP, POCOP, and PCOP pincer-ligands which have been investigated for many catalytic reactions including alkene hydrogenation, olefin isomerization, and CO2 hydrogenation. Asymmetric NCOP pincer ligands bearing a pendant aza-crown-ether group have recently been investigated, but crown-free versions have yet to be reported. We report the synthesis and characterization of Ir(III) species, (RNCOPiPr)Ir(H)(Cl), and related iridium carbonyl complexes, (RNCOPiPr)Ir(H)(Cl)(CO) and (RNCOPiPr)Ir(CO). Catalytic activity will also be discussed.