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Design and Assembly of Covalently Functionalised Polyoxofluorovanadate Molecular Hybrids
Author(s) -
Nicolaou Maria,
Papanikolaou Michael G.,
Tsipis Athanassios C.,
Kabanos Themistoklis A.,
Keramidas Anastasios D.,
Sproules Stephen,
Miras Haralampos N.
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201705730
Subject(s) - polyoxometalate , crystallography , density functional theory , electron paramagnetic resonance , chemistry , antiferromagnetism , singlet state , covalent bond , materials science , computational chemistry , excited state , atomic physics , nuclear magnetic resonance , organic chemistry , physics , condensed matter physics , catalysis
Mixed‐valent polyoxometalate (POM) clusters are one of the most interesting host species, showing a wide range of structural features and properties. The facile preparation and functionalisation of a mixed‐valent polyoxofluorovanadates is reported, where two electrons are trapped to antipodal sites of the clusters. The first members of this family of clusters with the general formula, [V V 12 V IV 2 O 16 ( μ ‐O) 10 ( μ 3 ‐O) 10 ( μ 3 ‐F) 2 (L) 2 ] 6− , where L: py=pyridine ( 1 ); pyr=pyrazine ( 2 ); im=imidazole ( 3 ), are unique organic‐inorganic hybrids with the addition of a N ‐donor ligand at either end of the polyoxofluorovanadate. The composition and connectivity of 1 – 3 were characterised by single‐crystal X‐ray diffraction and electrospray ionisation mass spectrometry. Electron paramagnetic resonance spectroscopy revealed that the two well‐separated V IV ions in each cluster are fully uncoupled with J= 0, giving a degenerate singlet–triplet ground state. This attenuation of the exchange interaction is probed with density functional theoretical calculations that reveal that the inclusion of the fluoride ion in the cluster produces a bond pathway biased toward destructive interference between competing ferromagnetic and antiferromagnetic interactions. These robust molecular materials are the ideal combination of desirable electronic properties, with an organic handle with which they can be integrated into spintronic circuitry for molecular devices.