Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species

Glaser T, Heidemeier M, Fröhlich R, Hildebrandt P, Bothe E, Bill E (2005)
Inorg. Chem. 44(15): 5467-5482.

Zeitschriftenaufsatz | Veröffentlicht | Englisch
 
Download
Es wurde kein Volltext hochgeladen. Nur Publikationsnachweis!
Autor/in
; ; ; ; ;
Abstract / Bemerkung
The coordination chemistries of the triple tetradentate triplesalen ligands H(6)talen, H(6)talen(t-Bu2), and H(6)talen(NO2) have been investigated with nickel(II). These triplesalen ligands provide three salen-like coordination environments bridged in a meta-phenylene arrangement by a phloroglucinol backbone. The structures of the complexes [(talen)Ni-3(II)], [(talen(t-Bu2))Ni-3(II)], and [(talen(NO2))Ni-3(II)] have been determined by single-crystal X-ray diffraction, All three compounds are composed of neutral trinuclear complexes with square-planar coordinated Ni-II ions in a salen-like coordination environment. Whereas the overall molecular structure of [(talen(NO2))Ni-II3] is nearly planar, the structures of [(talen)Ni-II3] and [(talen(t-Bu2))Ni-3(II)] are bowl-shaped as a result of ligand folding. The strongest ligand folding occurs at the central nickel-phenolate bond of [(talen(t-Bu2))Ni-3(II)], resulting in the formation of a chiral hemispherical pocket, The dependence of the physical properties by the substituents on the terminal phenolates has been studied by FTIR, resonance Raman, UV-vis-NIR absorption, and electrochemistry. The three nickel-salen subunits are electronically interacting via the 7, system of the bridging phloroglucinol backbone. The strength of this interaction is mediated by two opposing effects: the electron density at the terminal phenolates and the folding of the ligand at the central phenolates. The parent complex [(talen)Ni-3(II)] is irreversibly oxidized at 0.32 V versus ferrocenium/ferrocene (Fc(+)/ Fc), whereas [(talen(t-Bu2))Ni-3(II)] and [(talen(NO2))Ni-3(II)] exhibit reversible oxidations at 0.22 V versus Fc(+)/Fc and 0.52 V versus Fc(+)/Fc, respectively. The oxidized species [(talen(t-Bu2))Ni-3](+) and [(talen(NO2))Ni-3](+) undergo a valence-tautomeric transformation involving a Ni-II and a phenoxyl radical species, as observed by EPR spectroscopy. Thus, these oxidized forms exhibit the phenomena of valence tautomerism and mixed valence simultaneously. The extent of delocalization of the radical species and of the Ni-II species is discussed.
Stichworte
SCHIFF-BASE LIGANDS; ACHIRAL (SALEN)MANGANESE(III) COMPLEX; TRANSITION-METAL COMPLEXES; MAGNETIC-PROPERTIES; SALEN COMPLEXES; OXOCHROMIUM(V) CATIONS; ASYMMETRIC CATALYSIS; MOLECULAR-STRUCTURE; X-RAY; ENANTIOSELECTIVE EPOXIDATION
Erscheinungsjahr
2005
Zeitschriftentitel
Inorg. Chem.
Band
44
Ausgabe
15
Seite(n)
5467-5482
ISSN
0020-1669
eISSN
1520-510X
Page URI
https://pub.uni-bielefeld.de/record/1871868

Zitieren

Glaser T, Heidemeier M, Fröhlich R, Hildebrandt P, Bothe E, Bill E. Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species. Inorg. Chem. 2005;44(15):5467-5482.
Glaser, T., Heidemeier, M., Fröhlich, R., Hildebrandt, P., Bothe, E., & Bill, E. (2005). Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species. Inorg. Chem., 44(15), 5467-5482. doi:10.1021/ic050268x
Glaser, T., Heidemeier, M., Fröhlich, R., Hildebrandt, P., Bothe, E., and Bill, E. (2005). Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species. Inorg. Chem. 44, 5467-5482.
Glaser, T., et al., 2005. Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species. Inorg. Chem., 44(15), p 5467-5482.
T. Glaser, et al., “Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species”, Inorg. Chem., vol. 44, 2005, pp. 5467-5482.
Glaser, T., Heidemeier, M., Fröhlich, R., Hildebrandt, P., Bothe, E., Bill, E.: Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species. Inorg. Chem. 44, 5467-5482 (2005).
Glaser, Thorsten, Heidemeier, M, Fröhlich, R, Hildebrandt, P, Bothe, E, and Bill, E. “Trinuclear Nickel Complexes with Triplesalen Ligands: Simultaneous Occurrence of Mixed Valence and Valence Tautomerism in the Oxidized Species”. Inorg. Chem. 44.15 (2005): 5467-5482.

Export

Markieren/ Markierung löschen
Markierte Publikationen

Open Data PUB

Web of Science

Dieser Datensatz im Web of Science®

Quellen

PMID: 16022545
PubMed | Europe PMC

Suchen in

Google Scholar