en
Scientific article
English

Naphthalene Complexes. V. Arene Exchange Reactions in Naphthalenechromium Complexes

Published inJournal of organometallic chemistry, vol. 286, no. 2, p. 183-200
Publication date1985
Abstract

Di-?6-naphthalenechromium(0) (1) reacts at 150°C with benzene to yield (?6-naphthalene)(?6-benzene)chromium(0) (3) in 76% yield. In the presence of THF, 1 undergoes Lewis base catalyzed arene exchange at 80°C. Reactions of 1 with substituted arenes yield the mixed sandwich complexes 4 and 6–10 (arene = 1,4-C6H4Me2, 1,3,5-C6H3Me3, C6Me6, 1,4-C6H4(OMe)2, 1,4-C6H4F2 and 1,4-C10H6Me2). In all but one case (with 1,4-dimethylnaphthalene) exchange of a single naphthalene ligand is observed. In marked contrast to the lability of 1, dimesitylenechromium(0) (5) is inert to arene displacement in benzene up to 240°C. The molecular structure of 3 has been determined by X-ray crystallography. The crystal data are as follows: a 7.784(1), b 13.411(2), c 22.772(5) Å, Z = 8, space group Pbca. The structure was refined to a Rw value of 0.043. The naphthalene ligand in 3 is nearly planar and parallel to the approximately eclipsed benzene ring. Metal atom-ring distances are 1.631(9) and 1.611(4) Å for naphthalene and benzene, respectively. Catalyzed and uncatalyzed naphthalene exchanges in the sandwich complex are compared to the analogous reactions with the Cr(CO)3 complex 2. Naphthalene exchange in 2 in benzene is 103 to 104 times faster than arene exchange in other arenetricarbonylchromium compounds. The mild conditions for Lewis base catalyzed naphthalene exchange make 2 a good precursor of other arenetricarbonylchromium compounds. Examples include the Cr(CO)3 complexes of styrene, benzocyclobutene, 1-ethoxybenzocyclobutene, 1,8-dimethoxy-9,10-dihydroanthracene and 1,4-dimethylnaphthalene.

Citation (ISO format)
KUNDIG, Ernst Peter et al. Naphthalene Complexes. V. Arene Exchange Reactions in Naphthalenechromium Complexes. In: Journal of organometallic chemistry, 1985, vol. 286, n° 2, p. 183–200. doi: 10.1016/0022-328X(85)88005-0
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
ISSN of the journal0022-328X
493views
0downloads

Technical informations

Creation04/20/2010 10:09:28 AM
First validation04/20/2010 10:09:28 AM
Update time03/14/2023 3:27:42 PM
Status update03/14/2023 3:27:42 PM
Last indexation01/15/2024 7:51:08 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack