dc.contributor.author
Schweinfurth, David
dc.contributor.author
Klein, Johannes
dc.contributor.author
Hohloch, Stephan
dc.contributor.author
Dechert, Sebastian
dc.contributor.author
Demeshko, Serhiy
dc.contributor.author
Meyer, Franc
dc.contributor.author
Sarkar, Biprajit
dc.date.accessioned
2018-06-08T04:08:42Z
dc.date.available
2015-03-16T11:46:30.739Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/16669
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-20850
dc.description.abstract
The complexes [(tbta)Co(μ-CA-2H)Co(tbta)(CH3CN)](BF4)21 and
[(tbta)Co(μ-OH)2Co(tbta)](BF4)42 (tbta = tris[(1-benzyl-
1H-1,2,3-triazol-4-yl)methyl]amine and CA = chloranilic acid) were synthesized
and characterized by X-ray crystallography, SQUID magnetometry and NMR
spectroscopy. The reactions to form these complexes deliver 1 as a
paramagnetic species containing two high spin Co(II) centers, and 2 as a
diamagnetic compound with two low spin Co(III) centers. Structural analysis
shows that in 1 the capped-octahedral environment around the Co(II) centers is
highly distorted with rather long bonds between the metal and donor atoms. The
tbta ligand binds to the Co(II) centers through the three triazole nitrogen
donor atoms in a facial form, with the Co–N(amine) distance of 2.494(2) Å
acting as a capping bond to the octahedron. In the crystal an unusual
observation of one acetonitrile molecule statistically occupying the
coordination sites at both Co(II) centers is made. 1 displays a series of
intermolecular C–HCl and π–π interactions leading to extended three-
dimensional structures in the solid state. These interactions lead to the
formation of voids and explain why only one acetonitrile molecule can be bound
to the dinuclear complexes. In contrast to 1, the cobalt centers in 2 display
a more regular octahedral environment with shorter cobalt–donor atom
distances, as would be expected for a low spin Co(III) situation. The tbta
ligand acts as a perfect tetradentate ligand in this case with the
cobalt–N(amine) distance of 2.012(3) Å falling in the range of a normal bond.
Thus, we present the rare instances where the ligand tbta has been observed to
bind in a perfectly tetradentate fashion in its metal complexes. The room
temperature magnetic moment of 6.30 μB for 1 shows values typical of two high
spin Co(II) centers, and this value decreases at temperatures lower than 30 K
indicating a weak antiferromagnetic coupling and zero field splitting. Mass
spectrometric analysis of 2 provided evidence for the formation of an oxo-
bridged dicobalt complex in the gas phase.
en
dc.rights.uri
http://www.rsc.org/AboutUs/Copyright/Authordeposition.asp
dc.subject.ddc
500 Naturwissenschaften und Mathematik::540 Chemie
dc.title
Influencing the coordination mode of tbta (tbta = tris[(1-benzyl-
1H-1,2,3-triazol-4-yl)methyl]amine) in dicobalt complexes through changes in
metal oxidation states
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation
Dalton Trans. - 42 (2013),19, S. 6944-6952
dcterms.bibliographicCitation.doi
10.1039/C3DT00102D
dcterms.bibliographicCitation.url
http://pubs.rsc.org/en/Content/ArticleLanding/2013/DT/c3dt00102d#!divAbstract
refubium.affiliation
Biologie, Chemie, Pharmazie
de
refubium.mycore.fudocsId
FUDOCS_document_000000022062
refubium.resourceType.isindependentpub
no
refubium.mycore.derivateId
FUDOCS_derivate_000000004683
dcterms.accessRights.openaire
open access
dcterms.isPartOf.issn
1477-9226