Dynamic Au–C σ-Bonds Leading to an Efficient Synthesis of [n]Cycloparaphenylenes (n = 9 – 15) by a Self-Assembly

16 March 2022, Version 3
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

The transmetalation of the digold(I) complex [Au2Cl2(dcpm)] (1) (dcpm = bis(dicyclohexylphosphino)methane) with oligophenylene diboronic acids gave the triangular macrocyclic complexes [Au2(C6H4)x(dcpm)]3 (x = 3, 4, 5) with yields of over 70%. On the other hand, when the other digold(I) complex [Au2Cl2(dppm)] (1') (dcpm = bis(diphenylphosphino)methane) was used, only a negligible amount the triangular complex was obtained. The control experiments revealed that the dcpm ligand accelerated an intermolecular Au(I)–C σ-bond-exchange reaction, and that this high reversibility is the origin of the selective formation of the triangular complexes. Structural analyses and theoretical calculations indicate that dcpm ligand increases the electrophilicity of the Au atom in the complex, thus facilitating the exchange reaction, though cyclohexyl group is an electron-donating group. Furthermore, the oxidative chlorination of the macrocyclic gold complexes afforded a series of [n]cycloparaphenylenes (n = 9, 12, 15) in 78–88% isolated yields. The reaction of two different macrocyclic Au complexes gave a mixture of macrocyclic complexes incorporating different oligophenylene linkers, from which a mixture of [n]cycloparaphenylenes with various numbers of phenylene units was obtained in good yields.

Keywords

Cycloparaphenylenes
Au(I) Complex
Au(I)-C σ-Bonds
Kinetics
Self-Assembly

Supplementary materials

Title
Description
Actions
Title
Supporting Information
Description
Supporting Information
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Title
CCDC2108728_Au-3
Description
CCDC2108728_Au-3
Actions
Title
CCDC2108729_AuC-HH
Description
CCDC2108729_AuC-HH
Actions
Title
CCDC2108730_Au-4_C2_What_Is_This
Description
CCDC2108730_Au-4_C2_What_Is_This
Actions
Title
CCDC2108731_Au-4_D3
Description
CCDC2108731_Au-4_D3
Actions
Title
CCDC2108732_AuC-FF
Description
CCDC2108732_AuC-FF
Actions
Title
CCDC2108733_AuP-FF
Description
CCDC2108733_AuP-FF
Actions

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