Zinc Complexes of a Bioinspired Binucleating Ligand Platform - Equilibria in Solution and Structures in the Solid State
(2012) In European Journal of Inorganic Chemistry p.4728-4738- Abstract
- The zinc(II) coordination chemistry of the bioinspired bis(tetradentate) ligand 3,5-bis{bis[2-(1-methylimidazolyl)methyl]aminomethyl}pyrazole (L) was studied in detail both in solution and in the solid state. Six different species were determined in aqueous solution by means of potentiometry within the pH range 211, namely mononuclear [ZnH2L]4+, dinuclear [Zn2L]4+, [Zn2H1L]3+ and [Zn2H2L]2+, as well as tetranuclear [Zn4H5L2]3+ and [Zn4H6L2]2+. Complexes representing the protonation state of four of these species could be isolated and structurally characterized by X-ray diffraction, namely [ZnH2L(MeCN)](ClO4)4 (1), [Zn2H1L](SO3CF3)3 (4), [Zn2H1L(MeOHOMe)](ClO4)2 (5a), [Zn2H1L(OMe)](ClO4)2 (5b), and [(Zn2H1L)2(mu-O)(mu-OH)](ClO4)3 (6). In... (More)
- The zinc(II) coordination chemistry of the bioinspired bis(tetradentate) ligand 3,5-bis{bis[2-(1-methylimidazolyl)methyl]aminomethyl}pyrazole (L) was studied in detail both in solution and in the solid state. Six different species were determined in aqueous solution by means of potentiometry within the pH range 211, namely mononuclear [ZnH2L]4+, dinuclear [Zn2L]4+, [Zn2H1L]3+ and [Zn2H2L]2+, as well as tetranuclear [Zn4H5L2]3+ and [Zn4H6L2]2+. Complexes representing the protonation state of four of these species could be isolated and structurally characterized by X-ray diffraction, namely [ZnH2L(MeCN)](ClO4)4 (1), [Zn2H1L](SO3CF3)3 (4), [Zn2H1L(MeOHOMe)](ClO4)2 (5a), [Zn2H1L(OMe)](ClO4)2 (5b), and [(Zn2H1L)2(mu-O)(mu-OH)](ClO4)3 (6). In addition, a bis(pyrazolato)-bridged complex, [(ZnH1L)2](ClO4)2 (2), was obtained and structurally characterized, and it was found to exhibit ligand dynamics in solution. Both 5a and 5b are likely present in solution, which requires significant plasticity of the Zn...Zn distance (4.21 angstrom in 5a vs. 3.38 angstrom in 5b). Interconversion of 5a and 5b is proposed to be a facile process, supporting the idea that the ZnO2H3Zn moiety is a functionally relevant hydrolytic zincaqua structure in oligozinc metalloenzymes. The tetranuclear complex 6 that features two {Zn2H1L} subunits connected by a central mu-oxido-mu-hydroxido moiety is unprecedented in zinc(II) chemistry. Combining X-ray crystallography with potentiometry, ESI mass spectrometry, as well as NMR and EXAFS spectroscopy has provided a comprehensive picture of the multitude of species present in this rather complex system. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3244552
- author
- Woeckel, Simone ; Galezowska, Joanna ; Dechert, Sebastian ; Meyer-Klaucke, Wolfram ; Nordlander, Ebbe LU and Meyer, Franc
- organization
- publishing date
- 2012
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Zinc, N ligands, Pyrazolate li-gands, Binuclear complexes, Potentiometric titration, EXAFS spectroscopy
- in
- European Journal of Inorganic Chemistry
- issue
- 29
- pages
- 4728 - 4738
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- wos:000309467600024
- scopus:84867090656
- ISSN
- 1099-0682
- DOI
- 10.1002/ejic.201200269
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)
- id
- d69ba1ae-4412-4d15-ac9d-b555176ad206 (old id 3244552)
- date added to LUP
- 2016-04-01 10:06:07
- date last changed
- 2022-01-25 19:40:14
@article{d69ba1ae-4412-4d15-ac9d-b555176ad206,
abstract = {{The zinc(II) coordination chemistry of the bioinspired bis(tetradentate) ligand 3,5-bis{bis[2-(1-methylimidazolyl)methyl]aminomethyl}pyrazole (L) was studied in detail both in solution and in the solid state. Six different species were determined in aqueous solution by means of potentiometry within the pH range 211, namely mononuclear [ZnH2L]4+, dinuclear [Zn2L]4+, [Zn2H1L]3+ and [Zn2H2L]2+, as well as tetranuclear [Zn4H5L2]3+ and [Zn4H6L2]2+. Complexes representing the protonation state of four of these species could be isolated and structurally characterized by X-ray diffraction, namely [ZnH2L(MeCN)](ClO4)4 (1), [Zn2H1L](SO3CF3)3 (4), [Zn2H1L(MeOHOMe)](ClO4)2 (5a), [Zn2H1L(OMe)](ClO4)2 (5b), and [(Zn2H1L)2(mu-O)(mu-OH)](ClO4)3 (6). In addition, a bis(pyrazolato)-bridged complex, [(ZnH1L)2](ClO4)2 (2), was obtained and structurally characterized, and it was found to exhibit ligand dynamics in solution. Both 5a and 5b are likely present in solution, which requires significant plasticity of the Zn...Zn distance (4.21 angstrom in 5a vs. 3.38 angstrom in 5b). Interconversion of 5a and 5b is proposed to be a facile process, supporting the idea that the ZnO2H3Zn moiety is a functionally relevant hydrolytic zincaqua structure in oligozinc metalloenzymes. The tetranuclear complex 6 that features two {Zn2H1L} subunits connected by a central mu-oxido-mu-hydroxido moiety is unprecedented in zinc(II) chemistry. Combining X-ray crystallography with potentiometry, ESI mass spectrometry, as well as NMR and EXAFS spectroscopy has provided a comprehensive picture of the multitude of species present in this rather complex system.}},
author = {{Woeckel, Simone and Galezowska, Joanna and Dechert, Sebastian and Meyer-Klaucke, Wolfram and Nordlander, Ebbe and Meyer, Franc}},
issn = {{1099-0682}},
keywords = {{Zinc; N ligands; Pyrazolate li-gands; Binuclear complexes; Potentiometric titration; EXAFS spectroscopy}},
language = {{eng}},
number = {{29}},
pages = {{4728--4738}},
publisher = {{John Wiley & Sons Inc.}},
series = {{European Journal of Inorganic Chemistry}},
title = {{Zinc Complexes of a Bioinspired Binucleating Ligand Platform - Equilibria in Solution and Structures in the Solid State}},
url = {{http://dx.doi.org/10.1002/ejic.201200269}},
doi = {{10.1002/ejic.201200269}},
year = {{2012}},
}