Universität zu Köln

Nitsche, Sara, Schmitz, Simon, Stirnat, Kathrin, Sandleben, Aaron ORCID: 0000-0002-4141-7406 and Klein, Axel ORCID: 0000-0003-0093-9619 (2018). Controlling Nuclearity and Stereochemistry in Vanadyl(V) and Mixed Valent V-IV/V-V Complexes of Oxido-Pincer Pyridine-2,6-dimethanol Ligands. Z. Anorg. Allg. Chem., 644 (24). S. 1805 - 1816. WEINHEIM: WILEY-V C H VERLAG GMBH. ISSN 1521-3749

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Abstract

The coordination chemistry of three oxido-pincer ligands 2,6-(HOCR2)(2)(pyridine) (H2L) based on 2,6-pyridinedimethanol [R = H (H(2)pydim), Me (H(2)pydip), Ph (H(2)pyphen)] towards vanadium(V) was explored. Reaction of NH4VO3 with the protoligands H2L gave the dinuclear complexes [(L)OV(mu-O)VO(L)]. Mononuclear anionic species [VO2(L)](-), which were isolated as alkaline metal salts were obtained from reactions of [VO(acac)(2)] (acac(-) = acetylacetonate) and H2L under basic conditions and addition of HCl to these species allowed to isolate the unprecedented oxido chlorido complexes [VOCl(L)] for pydip and pyphen. Cyclic voltammograms of the dinuclear [V2O3(L)(2)] and mononuclear [VOCl(L)] complexes show reversible V-V/V-IV reduction waves, while corresponding waves of the anionic [VO2(L)](-) are completely irreversible. The mixed-valent V-IV/V-V species [V2O3(L)(2)](center dot-) were characterized by EPR and UV/Vis spectroelectrochemistry revealing a delocalized system with a 15 line EPR spectrum and an intervalence charge transfer (IVCT) band for the bulky pyphen ligand but localized radicals in case of the pydim and pydip derivatives (8 line EPR, no IVCT). DFT calculated structures of the three derivatives show an V-O-V arrangement for [V2O3(pyphen)(2)](center dot-) of about 145 degrees ideally suited for delocalization, whereas for [V2O3(pydip)(2)](center dot-) an angle of 128 degrees was found.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Nitsche, Sara UNSPECIFIED UNSPECIFIED UNSPECIFIED Schmitz, Simon UNSPECIFIED UNSPECIFIED UNSPECIFIED Stirnat, Kathrin UNSPECIFIED UNSPECIFIED UNSPECIFIED Sandleben, Aaron UNSPECIFIED orcid.org/0000-0002-4141-7406 UNSPECIFIED Klein, Axel UNSPECIFIED orcid.org/0000-0003-0093-9619 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-161636
DOI:	10.1002/zaac.201800352
Journal or Publication Title:	Z. Anorg. Allg. Chem.
Volume:	644
Number:	24
Page Range:	S. 1805 - 1816
Date:	2018
Publisher:	WILEY-V C H VERLAG GMBH
Place of Publication:	WEINHEIM
ISSN:	1521-3749
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Inorganic Chemistry
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language SINGLE-MOLECULE MAGNETS; CRYSTAL-STRUCTURE; OXIDOVANADIUM(V) COMPLEXES; COORDINATION CHEMISTRY; VANADIUM COMPLEXES; DNA-BINDING; PYRIDINE; BINUCLEAR; FAMILY; COPPER(II) Multiple languages Chemistry, Inorganic & Nuclear Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/16163