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Pentamethylcyclopentadienyl molybdenum(V) complexes derived from iodoanilines: Synthesis, structure, and rop of ε-caprolactone

Xing, Tian; Elsegood, Mark R. J.; Dale, Sophie H.; Redshaw, Carl


Tian Xing

Mark R. J. Elsegood

Sophie H. Dale

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Professor Carl Redshaw
Professor of Inorganic Materials Chemistry and REF Lead for Chemistry


The reaction of [Mo(η-C5Me5 )Cl4 ] with the ortho-, meta-, or para-iodo-functionalized anilines 2-IC6H4NH2, 3-IC6H4NH2, 4-IC6H4NH2 yields imido or amine products of the type [Mo(ηC5Me5 )Cl2 (IC6H4N)] (2-I, 1, 3-I, 3, 4-I, 5) or [Mo(η-C5Me5 )Cl4 (IC6H4NH2 )] (3-I, 2, 4-I, 4), respectively, depending on the reaction stoichiometry/conditions; we were unable to isolate an amine complex of the 2-I derivative. The reaction of [Mo(η-C5Me5 )Cl4 ] with one equivalent of 2-I,4-FC6H3NH2 in the presence of Et3N afforded [Mo(η-C5Me5 )Cl2 (2-I,4-FC6H3N)]·MeCN (6·MeCN), which, upon exposure to air, afforded the Mo(VI) imido complex [Mo(η-C5Me5)Cl3 (2-I,4-FC6H3N)] (7). For comparative studies, the structure of the aniline (C6H5NH2 )-derived complex [Mo(η-C5Me5 )Cl2 (2-C6H3N)] (8) has also been prepared. The molecular structures of 1–8 have been determined and reveal packing in the form of zig-zag chains or ladders. The complexes catalyze, in the presence of benzyl alcohol under N2, the ring-opening polymerization (ROP) of ε-caprolactone affording relatively low molecular weight products. The MALDI-ToF spectra indicate that a number of polymer series bearing a variety of end groups are formed. Conducting the ROPs as melts or under air results in the isolation of higher molecular weight products, again bearing a variety of end groups. Kinetic studies reveal the aniline-derived imido complex 8 performs best, whilst a meta-iodo substituent and a Mo(V) centre are also found to be beneficial. The structures of the side products 2-IC6H4NH3Cl and 3-IC6H4NH3Cl are also reported.


Xing, T., Elsegood, M. R. J., Dale, S. H., & Redshaw, C. (2021). Pentamethylcyclopentadienyl molybdenum(V) complexes derived from iodoanilines: Synthesis, structure, and rop of ε-caprolactone. Catalysts, 11(12), Article 1554.

Journal Article Type Article
Acceptance Date Dec 2, 2021
Online Publication Date Dec 20, 2021
Publication Date Dec 20, 2021
Deposit Date Dec 21, 2021
Publicly Available Date Dec 22, 2021
Journal Catalysts
Print ISSN 2073-4344
Electronic ISSN 2073-4344
Publisher MDPI
Peer Reviewed Peer Reviewed
Volume 11
Issue 12
Article Number 1554
Keywords Imido; Amine; Iodo; Molybdenum; Structure; Ring opening polymerization
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Copyright Statement
Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// 4.0/).

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