Synthesis and isomerization behavior of cyano-vinyl ferrocenes

Frank Strehler, Marcus Korb, Tobias Rueffer, Alexander Hildebrandt, Heinrich Lang

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The reaction of Z-FcC(Cl)]=CHC(O)H (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H4)) with KI/ZnO/NH2OH center dot center dot center dot HCl gave Z-FcC( Cl)]=CHC N, which on further treatment with ROH/KOH (R = Me, Et, Pr-i, OCH2CH2OH) or H2NCH2Ph produced Z-FcC(OR)]=CHC N, E-FcC(NHCH2Ph)]=CHC N and FcC(OCH2)(2)CH2C N. However, the use of the sterically demanding OtBu group resulted in the elimination of HCl giving 3-ferrocenylpropynenitrile. Complex [PtCl2(N CCH=C(Cl)Fc)(2)], as a mixture of E/Z and cis/trans isomers, was accessible by the addition of [PtCl2] to Z-FcC(Cl)=CHC(O) H. When Z-FcC(OR)]=CHC N (R = Me; Et; Pr-i) was reacted with [PtCl2] in the molar ratio of 2:1, solely trans-[PtCl2(E-N CCH=C(OR)Fc)(2)] was formed with isomerization of the C, C double bond from Z to E. These are the first examples for the entirely conversion of Z to E isomers of coordinated acrylonitriles. The stereochemistry of Z-FcC(OR)]=CHC N is maintained, when the Pt source is excluded, while a combination of heat and light treatment resulted in the partial isomerization. The electrochemical properties of the chloro-and the methoxy-functionalized vinyl ferrocene were studied. In the corresponding Pt complexes an anodic shift of the ferrocenyl units is observed due to an electron density transfer towards the Pt atom. Spectroelectrochemical studies of the Pt complexes allowed no definite verification that an electronic interaction between the redox-active ferrocenyl/ferrocenium termini occurs even when high Delta E-p values in the cyclic indicate that two individual oxidation processes might take place in a close potential range. (C) 2016 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)89-97
Number of pages9
JournalJournal of Organometallic Chemistry
Volume820
DOIs
Publication statusPublished - 1 Oct 2016
Externally publishedYes

Cite this

Strehler, Frank ; Korb, Marcus ; Rueffer, Tobias ; Hildebrandt, Alexander ; Lang, Heinrich. / Synthesis and isomerization behavior of cyano-vinyl ferrocenes. In: Journal of Organometallic Chemistry. 2016 ; Vol. 820. pp. 89-97.
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title = "Synthesis and isomerization behavior of cyano-vinyl ferrocenes",
abstract = "The reaction of Z-FcC(Cl)]=CHC(O)H (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H4)) with KI/ZnO/NH2OH center dot center dot center dot HCl gave Z-FcC( Cl)]=CHC N, which on further treatment with ROH/KOH (R = Me, Et, Pr-i, OCH2CH2OH) or H2NCH2Ph produced Z-FcC(OR)]=CHC N, E-FcC(NHCH2Ph)]=CHC N and FcC(OCH2)(2)CH2C N. However, the use of the sterically demanding OtBu group resulted in the elimination of HCl giving 3-ferrocenylpropynenitrile. Complex [PtCl2(N CCH=C(Cl)Fc)(2)], as a mixture of E/Z and cis/trans isomers, was accessible by the addition of [PtCl2] to Z-FcC(Cl)=CHC(O) H. When Z-FcC(OR)]=CHC N (R = Me; Et; Pr-i) was reacted with [PtCl2] in the molar ratio of 2:1, solely trans-[PtCl2(E-N CCH=C(OR)Fc)(2)] was formed with isomerization of the C, C double bond from Z to E. These are the first examples for the entirely conversion of Z to E isomers of coordinated acrylonitriles. The stereochemistry of Z-FcC(OR)]=CHC N is maintained, when the Pt source is excluded, while a combination of heat and light treatment resulted in the partial isomerization. The electrochemical properties of the chloro-and the methoxy-functionalized vinyl ferrocene were studied. In the corresponding Pt complexes an anodic shift of the ferrocenyl units is observed due to an electron density transfer towards the Pt atom. Spectroelectrochemical studies of the Pt complexes allowed no definite verification that an electronic interaction between the redox-active ferrocenyl/ferrocenium termini occurs even when high Delta E-p values in the cyclic indicate that two individual oxidation processes might take place in a close potential range. (C) 2016 Elsevier B.V. All rights reserved.",
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author = "Frank Strehler and Marcus Korb and Tobias Rueffer and Alexander Hildebrandt and Heinrich Lang",
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Synthesis and isomerization behavior of cyano-vinyl ferrocenes. / Strehler, Frank; Korb, Marcus; Rueffer, Tobias; Hildebrandt, Alexander; Lang, Heinrich.

In: Journal of Organometallic Chemistry, Vol. 820, 01.10.2016, p. 89-97.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Synthesis and isomerization behavior of cyano-vinyl ferrocenes

AU - Strehler, Frank

AU - Korb, Marcus

AU - Rueffer, Tobias

AU - Hildebrandt, Alexander

AU - Lang, Heinrich

PY - 2016/10/1

Y1 - 2016/10/1

N2 - The reaction of Z-FcC(Cl)]=CHC(O)H (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H4)) with KI/ZnO/NH2OH center dot center dot center dot HCl gave Z-FcC( Cl)]=CHC N, which on further treatment with ROH/KOH (R = Me, Et, Pr-i, OCH2CH2OH) or H2NCH2Ph produced Z-FcC(OR)]=CHC N, E-FcC(NHCH2Ph)]=CHC N and FcC(OCH2)(2)CH2C N. However, the use of the sterically demanding OtBu group resulted in the elimination of HCl giving 3-ferrocenylpropynenitrile. Complex [PtCl2(N CCH=C(Cl)Fc)(2)], as a mixture of E/Z and cis/trans isomers, was accessible by the addition of [PtCl2] to Z-FcC(Cl)=CHC(O) H. When Z-FcC(OR)]=CHC N (R = Me; Et; Pr-i) was reacted with [PtCl2] in the molar ratio of 2:1, solely trans-[PtCl2(E-N CCH=C(OR)Fc)(2)] was formed with isomerization of the C, C double bond from Z to E. These are the first examples for the entirely conversion of Z to E isomers of coordinated acrylonitriles. The stereochemistry of Z-FcC(OR)]=CHC N is maintained, when the Pt source is excluded, while a combination of heat and light treatment resulted in the partial isomerization. The electrochemical properties of the chloro-and the methoxy-functionalized vinyl ferrocene were studied. In the corresponding Pt complexes an anodic shift of the ferrocenyl units is observed due to an electron density transfer towards the Pt atom. Spectroelectrochemical studies of the Pt complexes allowed no definite verification that an electronic interaction between the redox-active ferrocenyl/ferrocenium termini occurs even when high Delta E-p values in the cyclic indicate that two individual oxidation processes might take place in a close potential range. (C) 2016 Elsevier B.V. All rights reserved.

AB - The reaction of Z-FcC(Cl)]=CHC(O)H (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H4)) with KI/ZnO/NH2OH center dot center dot center dot HCl gave Z-FcC( Cl)]=CHC N, which on further treatment with ROH/KOH (R = Me, Et, Pr-i, OCH2CH2OH) or H2NCH2Ph produced Z-FcC(OR)]=CHC N, E-FcC(NHCH2Ph)]=CHC N and FcC(OCH2)(2)CH2C N. However, the use of the sterically demanding OtBu group resulted in the elimination of HCl giving 3-ferrocenylpropynenitrile. Complex [PtCl2(N CCH=C(Cl)Fc)(2)], as a mixture of E/Z and cis/trans isomers, was accessible by the addition of [PtCl2] to Z-FcC(Cl)=CHC(O) H. When Z-FcC(OR)]=CHC N (R = Me; Et; Pr-i) was reacted with [PtCl2] in the molar ratio of 2:1, solely trans-[PtCl2(E-N CCH=C(OR)Fc)(2)] was formed with isomerization of the C, C double bond from Z to E. These are the first examples for the entirely conversion of Z to E isomers of coordinated acrylonitriles. The stereochemistry of Z-FcC(OR)]=CHC N is maintained, when the Pt source is excluded, while a combination of heat and light treatment resulted in the partial isomerization. The electrochemical properties of the chloro-and the methoxy-functionalized vinyl ferrocene were studied. In the corresponding Pt complexes an anodic shift of the ferrocenyl units is observed due to an electron density transfer towards the Pt atom. Spectroelectrochemical studies of the Pt complexes allowed no definite verification that an electronic interaction between the redox-active ferrocenyl/ferrocenium termini occurs even when high Delta E-p values in the cyclic indicate that two individual oxidation processes might take place in a close potential range. (C) 2016 Elsevier B.V. All rights reserved.

KW - Ferrocene

KW - Alkenyl

KW - Nitrile

KW - Isomerization

KW - Electrochemistry

KW - Solid state structure

KW - INTRAMOLECULAR ELECTRONIC COMMUNICATION

KW - METAL-METAL INTERACTIONS

KW - MOLECULAR WIRES

KW - NONAQUEOUS SOLVENTS

KW - COMPLEXES

KW - CHEMISTRY

KW - ELECTROCHEMISTRY

KW - DERIVATIVES

KW - OXIDATION

KW - RUTHENIUM

U2 - 10.1016/j.jorganchem.2016.07.013

DO - 10.1016/j.jorganchem.2016.07.013

M3 - Article

VL - 820

SP - 89

EP - 97

JO - Journal of Organometallic Chemistry

JF - Journal of Organometallic Chemistry

SN - 0022-328X

ER -