Control of {eta}{sup 2}-coordination vs C-H bond activation by rhodium. The role of aromatic resonance energies

Journal Article · Wed Aug 25 04:00:00 EDT 1993 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00070a012· OSTI ID:41659

Chin, R M; Dong, L; Duckett, S B; Jones, W D ^[1]; Partridge, M G; Perutz, R N ^[2]

---

1. Univ. of Rochester, NY (United States)
2. Univ. of York (United Kingdom)

The reactions of a series of fused polycyclic arenes with (C{sub 5}Me{sub 5})Rh(PMe{sub 3})(Ph)H and (C{sub 5}H{sub 5})Rh(PMe{sub 3})-(Ph)H have been examined, and the thermodynamic preferences for {eta}{sup 2}-arene coordination vs C-H bond activation have been determined. While naphthalene, perylene, and triphenylene give equilibrium mixtures of both C-H activation and {eta}{sup 2}-complexes, phenanthrene, anthracene, 2-methoxynaphthalene,2,6-dimethoxynaphthalene, pyrene, and fluoranthene give only {eta}{sup 2}-complexes (C{sub 5}Me{sub 5} complexes). Naphthalene and several of the polycyclic aromatics are found to give bis-{eta}{sup 2}-complexes upon extended reaction. Electron-withdrawing groups as in p-C{sub 6}H{sub 4}(CF{sub 3}){sub 2} and m-C{sub 6}H{sub 4}(CF{sub 3}){sub 2} are also found to promote {eta}{sup 2}-coordination in monocyclic arenes (C{sub 5}H{sub 5} complexes). A C{sub 5}H{sub 5} ligand favors {eta}{sup 2}-coordination compared to a C{sub 5}Me{sub 5} ligand, as does rhodium compared to iridium. The effects of resonance, specifically the differences in the Huckel energies of the {eta}{sup 2}-bound vs free ligand, are believed to control the C-H activation/{eta}{sup 2}-coordination equilibria in polycyclic systems. The perylene complex (C{sub 5}Me{sub 5})Rh(PMe{sub 3})({eta}{sup 2}-perylene) has been found to crystallize in monoclinic space group C2/c, with a = 32.927(10)A, b = 10.125(2) A, c = 18.129(8) A, {beta} = 100.30(3){degree}, V = 5946.5(6.3) A{sup 3}, and Z = 8. 29 refs., 3 figs., 6 tabs.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-86ER13569
• OSTI ID: 41659
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 17 Vol. 115; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ANTHRACENE
CHEMICAL REACTIONS
EXPERIMENTAL DATA
LIGANDS
NAPHTHALENE
NUCLEAR MAGNETIC RESONANCE
ORGANOMETALLIC COMPOUNDS
PERYLENE
PHENANTHRENE
POLYCYCLIC AROMATIC HYDROCARBONS
PYRENE
RHODIUM COMPLEXES
THERMODYNAMICS
TRIPHENYLENE