Substituent Effects and Supramolecular Interactions of Titanocene(III) Chloride: Implications for Catalysis in Single Electron Steps

Andreas Gansaeuer; Christian Kube; Kim Daasbjerg; Rebecca Sure; Stefan Grimme; Godfred D. Fianu; Dhandapani V. Sadasivam; Robert A. Flowers

doi:10.1021/ja4121567

Substituent Effects and Supramolecular Interactions of Titanocene(III) Chloride: Implications for Catalysis in Single Electron Steps

Andreas Gansaeuer^*, Christian Kube, Kim Daasbjerg, Rebecca Sure, Stefan Grimme, Godfred D. Fianu, Dhandapani V. Sadasivam, Robert A. Flowers

^*Corresponding author for this work

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

71 Citations (Scopus)

Abstract

The electrochemical properties of titanocene(III) complexes and their stability in THF in the presence and absence of chloride additives were studied by cyclic voltammetry (CV) and computational methods. The anodic peak potentials of the titanocenes can be decreased by as much as 0.47 V through the addition of an electron-withdrawing substituent (CO2Me or CN) to the cyclopentadienyl ring when compared with Cp2TiCl. For the first time, it is demonstrated that under the conditions of catalytic applications low-valent titanocenes can decompose by loss of the substituted ligand. The recently discovered effect of stabilizing titanocene(III) catalysts by chloride additives was analyzed by CV, kinetic, and computational studies. An unprecedented supramolecular interaction between [(C5H4R)(2)TiCl2](-) and hydrochloride cations through reversible hydrogen bonding is proposed as a mechanism for the action of the additives. This study provides the critical information required for the rational design of titanocene-catalyzed reactions in single electron steps.

Original language	English
Journal	Journal of the American Chemical Society
Volume	136
Issue	4
Pages (from-to)	1663-1671
Number of pages	9
ISSN	0002-7863
DOIs	https://doi.org/10.1021/ja4121567
Publication status	Published - 2014

Keywords

TRANSFER RADICAL POLYMERIZATION
TRANSITION-METAL-COMPLEXES
HALIDE-PROMOTED REDUCTIONS
ATOM-TRANSFER
4-EXO CYCLIZATIONS
ADDITION-REACTIONS
STRAIGHTFORWARD SYNTHESIS
EPOXYPOLYENE CYCLIZATION
HOMOLYTIC SUBSTITUTION
HOMOGENEOUS CATALYSIS

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@article{3794910715ed48cd91c6d9e79b6cca60,

title = "Substituent Effects and Supramolecular Interactions of Titanocene(III) Chloride: Implications for Catalysis in Single Electron Steps",

abstract = "The electrochemical properties of titanocene(III) complexes and their stability in THF in the presence and absence of chloride additives were studied by cyclic voltammetry (CV) and computational methods. The anodic peak potentials of the titanocenes can be decreased by as much as 0.47 V through the addition of an electron-withdrawing substituent (CO2Me or CN) to the cyclopentadienyl ring when compared with Cp2TiCl. For the first time, it is demonstrated that under the conditions of catalytic applications low-valent titanocenes can decompose by loss of the substituted ligand. The recently discovered effect of stabilizing titanocene(III) catalysts by chloride additives was analyzed by CV, kinetic, and computational studies. An unprecedented supramolecular interaction between [(C5H4R)(2)TiCl2](-) and hydrochloride cations through reversible hydrogen bonding is proposed as a mechanism for the action of the additives. This study provides the critical information required for the rational design of titanocene-catalyzed reactions in single electron steps.",

keywords = "TRANSFER RADICAL POLYMERIZATION, TRANSITION-METAL-COMPLEXES, HALIDE-PROMOTED REDUCTIONS, ATOM-TRANSFER, 4-EXO CYCLIZATIONS, ADDITION-REACTIONS, STRAIGHTFORWARD SYNTHESIS, EPOXYPOLYENE CYCLIZATION, HOMOLYTIC SUBSTITUTION, HOMOGENEOUS CATALYSIS",

author = "Andreas Gansaeuer and Christian Kube and Kim Daasbjerg and Rebecca Sure and Stefan Grimme and Fianu, {Godfred D.} and Sadasivam, {Dhandapani V.} and Flowers, {Robert A.}",

year = "2014",

doi = "10.1021/ja4121567",

language = "English",

volume = "136",

pages = "1663--1671",

journal = "Journal of the American Chemical Society",

issn = "0002-7863",

publisher = "American Chemical Society",

number = "4",

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Substituent Effects and Supramolecular Interactions of Titanocene(III) Chloride: Implications for Catalysis in Single Electron Steps. / Gansaeuer, Andreas; Kube, Christian; Daasbjerg, Kim et al.
In: Journal of the American Chemical Society, Vol. 136, No. 4, 2014, p. 1663-1671.

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

TY - JOUR

T1 - Substituent Effects and Supramolecular Interactions of Titanocene(III) Chloride

T2 - Implications for Catalysis in Single Electron Steps

AU - Gansaeuer, Andreas

AU - Kube, Christian

AU - Daasbjerg, Kim

AU - Sure, Rebecca

AU - Grimme, Stefan

AU - Fianu, Godfred D.

AU - Sadasivam, Dhandapani V.

AU - Flowers, Robert A.

PY - 2014

Y1 - 2014

N2 - The electrochemical properties of titanocene(III) complexes and their stability in THF in the presence and absence of chloride additives were studied by cyclic voltammetry (CV) and computational methods. The anodic peak potentials of the titanocenes can be decreased by as much as 0.47 V through the addition of an electron-withdrawing substituent (CO2Me or CN) to the cyclopentadienyl ring when compared with Cp2TiCl. For the first time, it is demonstrated that under the conditions of catalytic applications low-valent titanocenes can decompose by loss of the substituted ligand. The recently discovered effect of stabilizing titanocene(III) catalysts by chloride additives was analyzed by CV, kinetic, and computational studies. An unprecedented supramolecular interaction between [(C5H4R)(2)TiCl2](-) and hydrochloride cations through reversible hydrogen bonding is proposed as a mechanism for the action of the additives. This study provides the critical information required for the rational design of titanocene-catalyzed reactions in single electron steps.

AB - The electrochemical properties of titanocene(III) complexes and their stability in THF in the presence and absence of chloride additives were studied by cyclic voltammetry (CV) and computational methods. The anodic peak potentials of the titanocenes can be decreased by as much as 0.47 V through the addition of an electron-withdrawing substituent (CO2Me or CN) to the cyclopentadienyl ring when compared with Cp2TiCl. For the first time, it is demonstrated that under the conditions of catalytic applications low-valent titanocenes can decompose by loss of the substituted ligand. The recently discovered effect of stabilizing titanocene(III) catalysts by chloride additives was analyzed by CV, kinetic, and computational studies. An unprecedented supramolecular interaction between [(C5H4R)(2)TiCl2](-) and hydrochloride cations through reversible hydrogen bonding is proposed as a mechanism for the action of the additives. This study provides the critical information required for the rational design of titanocene-catalyzed reactions in single electron steps.

KW - TRANSFER RADICAL POLYMERIZATION

KW - TRANSITION-METAL-COMPLEXES

KW - HALIDE-PROMOTED REDUCTIONS

KW - ATOM-TRANSFER

KW - 4-EXO CYCLIZATIONS

KW - ADDITION-REACTIONS

KW - STRAIGHTFORWARD SYNTHESIS

KW - EPOXYPOLYENE CYCLIZATION

KW - HOMOLYTIC SUBSTITUTION

KW - HOMOGENEOUS CATALYSIS

U2 - 10.1021/ja4121567

DO - 10.1021/ja4121567

M3 - Journal article

C2 - 24397383

SN - 0002-7863

VL - 136

SP - 1663

EP - 1671

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 4

ER -

Substituent Effects and Supramolecular Interactions of Titanocene(III) Chloride: Implications for Catalysis in Single Electron Steps

Abstract

Keywords

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