Journal Article

FZJ-2020-00805

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Conductive Self-Assembled Monolayers of Paramagnetic {CoIICo4III} and {Co4IICo2III} Coordination Clusters on Gold Surfaces

Schmitz, S.FZJ* ; Qiu, X. ; Glöß, M.FZJ* ; van Leusen, J. ; Izarova, N. V.FZJ* ; Nadeem, M. A. ; Griebel, J. ; Chiechi, R. C. ; Kögerler, P. (Corresponding author)FZJ* ; Monakhov, K. Y.FZJ*

2019
Frontiers Media Lausanne

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Please use a persistent id in citations: http://hdl.handle.net/2128/24146  doi:10.3389/fchem.2019.00681

Abstract: Two polynuclear cobalt(II,III) complexes, [Co5(N3)4(N-n-bda)4(bza·SMe)2] (1) and [Co6(N3)4(N-n-bda)2(bza·SMe)5(MeOH)4]Cl (2), where Hbza·SMe = 4-(methylthio)benzoic acid and N-n-H2bda = N-n-butyldiethanolamine, were synthesized and fully characterized by various techniques. Compound 1 exhibits an unusual, approximately C2-symmetric {CoIICoIII4} core of two isosceles Co3 triangles with perpendicularly oriented planes, sharing a central, high-spin CoII ion residing in a distorted tetrahedral coordination environment. This central CoII ion is connected to four outer, octahedrally coordinated low-spin CoIII ions via oxo bridges. Compound 2 comprises a semi-circular {CoII4CoIII2} motif of four non-interacting high-spin CoII and two low-spin CoIII centers in octahedral coordination environments. Self-assembled monolayers (SAMs) of 1 and 2 were physisorbed on template-stripped gold surfaces contacted by an eutectic gallium-indium (EGaIn) tip. The acquired current density-voltage (I-V) data revealed that the cobalt-based SAMs are more electrically robust than those of the previously reported dinuclear {CuIILnIII} complexes with Ln = Gd, Tb, Dy, or Y (Schmitz et al., 2018a). In addition, between 170 and 220°C, the neutral, mixed-valence compound 1 undergoes a redox modification, yielding a {Co5}-based coordination cluster (1-A) with five non-interacting, high-spin octahedral CoII centers as indicated by SQUID magnetometry analysis in combination with X-ray photoelectron spectroscopy and infrared spectroscopy. Solvothermal treatment of 1 results in a high-nuclearity coordination cluster, [Co10(N3)2(N-n-bda)6(bza·SMe)6] (3), containing 10 virtually non-interacting high-spin CoII centers.

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Contributing Institute(s):

1. Elektronische Materialien (PGI-7)
2. JARA-FIT (JARA-FIT)
3. Elektronische Eigenschaften (PGI-6)

Research Program(s):

1. 524 - Controlling Collective States (POF3-524) (POF3-524)

Appears in the scientific report 2019

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Database coverage:
; ; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; PubMed Central ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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