C O M M U N I C A T I O N S
t
despite 9 having bulkier Bu groups. Recently, in-plane conformation
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Figure 4. Crystal structure of [PBP](ethylene)iridium(I) complex 8 (50%
thermal ellipsoids; hydrogen atoms were omitted for clarity). Selected bond
lengths (Å) and angles (deg): Ir-B, 2.048(3); Ir-C(25), 2.205(3); Ir-C(26),
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1
1
1
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In conclusion, we synthesized the PBP pincer ligand precursor 2
and demonstrated its complexation with iridium(I) to afford the
coordinatively unsaturated [PBP](hydrido)chloroiridium complex 3 via
B-H oxidative addition. The reaction of 3 with carbon monoxide
produced [PBP](hydrido)chloro(carbonyl)iridium 7. The longer Ir-Cl
bond length of 7 than that of 8 revealed a stronger σ-donor ability of
the PBP ligand than that of PCP. Complex 3 was also converted to
2
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[PBP](ethylene)iridium(I) complex 9 by reaction with LiTMP under
an ethylene atmosphere. Applications of the easily prepared PBP pincer
complexes to catalytic reactions are under investigation.
Acknowledgment. This work was supported by KAKENHI (Nos.
21245023 and 21685006) from MEXT, Japan. M.Y. thanks the General
(7) Clark, G. R.; Irvine, G. J.; Roper, W. R.; Wright, L. J. J. Organomet. Chem.
2
003, 680, 81–88.
Sekiyu Research Promotion Foundation. Y.S. acknowledges a JSPS
fellowship for young scientists. The authors thank Profs. Mitsuhiko
Shionoya and Shuichi Hiraoka for measurement of ESI-TOF MS.
(
2 2
8) A related compound has been synthesized from Ph PH, CH O, and 1,2-
diamino-4-methylbenzene. Zhang, Q. Z.; Ly, T.; Slawin, A. M. Z.; Woollins,
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11
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Supporting Information Available: All experimental procedures,
spectroscopic data of new compounds, details of computational study,
and CIF files of 2, 3, and 7-9. This material is available free of charge
via the Internet at http://pubs.acs.org.
(
(
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