Molecular Tweezers with Freely Rotating Linker and Porphyrin Moieties

Rhys Murphy; Duc-Truc Pham; Stephen Lincoln; Martin Johnston

doi:10.1002/ejoc.201300207

Molecular Tweezers with Freely Rotating Linker and Porphyrin Moieties

Rhys Murphy, Duc-Truc Pham, Stephen Lincoln, Martin Johnston

Research output: Contribution to journal › Article › peer-review

11 Citations (Scopus)

Abstract

Molecular tweezers were synthesised by using a microwave accelerated alkene plus cyclobutane epoxide reaction between norbornyl appended porphyrin moieties and a diepoxide functionalised phenyl diimide spacer. The tweezers contain several rotational degrees of freedom; about the porphyrin with respect to the norbornyl linker, and between the two norbornyl backbone sections. The ability of Zn^II metallated tweezer 1 to complex 1,4-diazabicyclo[2.2.2]octane (DABCO) was studied by UV/Vis and ¹H NMR spectroscopy and multivariate global spectral analysis. The system was found to form a strong 1:1 intramolecular complex (1:DABCO) with an association constant of K₁₁ = 8.1 × 10⁷ M^-1, transforming to a 1:2 open complex [1:(DABCO)₂] with K₁₂ = 2.7 × 10⁹ M ^-2 at high concentrations of DABCO. Usually molecular tweezers possess a high degree of preorganisation, but we have found that the introduction of several rotational degrees of freedom has little impact on association constant strength.

Original language	English
Pages (from-to)	2985-2993
Number of pages	9
Journal	European Journal of Organic Chemistry
Volume	2013
Issue number	15
DOIs	https://doi.org/10.1002/ejoc.201300207
Publication status	Published - May 2013

Keywords

Cycloaddition
Metalloporphyrins
Molecular recognition
Porphyrinoids
Sandwich complexes
Supramolecular chemistry

Access to Document

10.1002/ejoc.201300207

Cite this

@article{6a41445441eb40aa881590621e189fb3,

title = "Molecular Tweezers with Freely Rotating Linker and Porphyrin Moieties",

abstract = "Molecular tweezers were synthesised by using a microwave accelerated alkene plus cyclobutane epoxide reaction between norbornyl appended porphyrin moieties and a diepoxide functionalised phenyl diimide spacer. The tweezers contain several rotational degrees of freedom; about the porphyrin with respect to the norbornyl linker, and between the two norbornyl backbone sections. The ability of ZnII metallated tweezer 1 to complex 1,4-diazabicyclo[2.2.2]octane (DABCO) was studied by UV/Vis and 1H NMR spectroscopy and multivariate global spectral analysis. The system was found to form a strong 1:1 intramolecular complex (1:DABCO) with an association constant of K11 = 8.1 × 107 M-1, transforming to a 1:2 open complex [1:(DABCO)2] with K12 = 2.7 × 109 M -2 at high concentrations of DABCO. Usually molecular tweezers possess a high degree of preorganisation, but we have found that the introduction of several rotational degrees of freedom has little impact on association constant strength.",

keywords = "Cycloaddition, Metalloporphyrins, Molecular recognition, Porphyrinoids, Sandwich complexes, Supramolecular chemistry",

author = "Rhys Murphy and Duc-Truc Pham and Stephen Lincoln and Martin Johnston",

year = "2013",

month = may,

doi = "10.1002/ejoc.201300207",

language = "English",

volume = "2013",

pages = "2985--2993",

journal = "European Journal of Organic Chemistry",

issn = "1434-193X",

publisher = "Wiley-VCH Verlag",

number = "15",

}

TY - JOUR

T1 - Molecular Tweezers with Freely Rotating Linker and Porphyrin Moieties

AU - Murphy, Rhys

AU - Pham, Duc-Truc

AU - Lincoln, Stephen

AU - Johnston, Martin

PY - 2013/5

Y1 - 2013/5

N2 - Molecular tweezers were synthesised by using a microwave accelerated alkene plus cyclobutane epoxide reaction between norbornyl appended porphyrin moieties and a diepoxide functionalised phenyl diimide spacer. The tweezers contain several rotational degrees of freedom; about the porphyrin with respect to the norbornyl linker, and between the two norbornyl backbone sections. The ability of ZnII metallated tweezer 1 to complex 1,4-diazabicyclo[2.2.2]octane (DABCO) was studied by UV/Vis and 1H NMR spectroscopy and multivariate global spectral analysis. The system was found to form a strong 1:1 intramolecular complex (1:DABCO) with an association constant of K11 = 8.1 × 107 M-1, transforming to a 1:2 open complex [1:(DABCO)2] with K12 = 2.7 × 109 M -2 at high concentrations of DABCO. Usually molecular tweezers possess a high degree of preorganisation, but we have found that the introduction of several rotational degrees of freedom has little impact on association constant strength.

AB - Molecular tweezers were synthesised by using a microwave accelerated alkene plus cyclobutane epoxide reaction between norbornyl appended porphyrin moieties and a diepoxide functionalised phenyl diimide spacer. The tweezers contain several rotational degrees of freedom; about the porphyrin with respect to the norbornyl linker, and between the two norbornyl backbone sections. The ability of ZnII metallated tweezer 1 to complex 1,4-diazabicyclo[2.2.2]octane (DABCO) was studied by UV/Vis and 1H NMR spectroscopy and multivariate global spectral analysis. The system was found to form a strong 1:1 intramolecular complex (1:DABCO) with an association constant of K11 = 8.1 × 107 M-1, transforming to a 1:2 open complex [1:(DABCO)2] with K12 = 2.7 × 109 M -2 at high concentrations of DABCO. Usually molecular tweezers possess a high degree of preorganisation, but we have found that the introduction of several rotational degrees of freedom has little impact on association constant strength.

KW - Cycloaddition

KW - Metalloporphyrins

KW - Molecular recognition

KW - Porphyrinoids

KW - Sandwich complexes

KW - Supramolecular chemistry

UR - http://www.scopus.com/inward/record.url?scp=84877751865&partnerID=8YFLogxK

U2 - 10.1002/ejoc.201300207

DO - 10.1002/ejoc.201300207

M3 - Article

SN - 1434-193X

VL - 2013

SP - 2985

EP - 2993

JO - European Journal of Organic Chemistry

JF - European Journal of Organic Chemistry

IS - 15

ER -

Molecular Tweezers with Freely Rotating Linker and Porphyrin Moieties

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this