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Transition Metal Bisdithiolene Complexes Based on Extended Ligands with Fused Tetrathiafulvalene and Thiophene Moieties: New Single‐Component Molecular Metals
Author(s) -
Nunes João P. M.,
Figueira Mauro J.,
Belo Dulce,
Santos Isabel C.,
Ribeiro Bruno,
Lopes Elsa B.,
Henriques Rui T.,
VidalGancedo Jose,
Veciana Jaume,
Rovira Concepció,
Almeida Manuel
Publication year - 2007
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.200701050
Subject(s) - tetrathiafulvalene , nickel , cyclic voltammetry , crystallography , electron paramagnetic resonance , transition metal , single crystal , magnetic susceptibility , chemistry , diamagnetism , metal , thiophene , materials science , molecule , electrochemistry , nuclear magnetic resonance , electrode , organic chemistry , physics , quantum mechanics , magnetic field , catalysis
The gold and nickel bisdithiolene complexes based on new highly extended ligands incorporating fused tetrathiafulvalene and thiophene moieties (α‐tdt=thiophenetetrathiafulvalenedithiolate and dtdt=dihydro‐ thiophenetetrathiafulvalenedithiolate), were prepared and characterised by using cyclic voltammetry, single crystal X‐ray diffraction, EPR, magnetic susceptibility and electrical transport measurements. These complexes, initially obtained under anaerobic conditions as diamagnetic gold monoanic [ n Bu 4 N][Au(α‐tdt) 2 ] ( 4 ), [ n Bu 4 N][Au(dtdt) 2 ] ( 3 ) and nickel dianionic species [( n Bu 4 N) 2 ][Ni(α‐tdt) 2 ] ( 8 ), [( n Bu 4 N) 2 ][Ni(dtdt) 2 ] ( 7 ), can be easily oxidised to the stable neutral state just by air or iodine exposure. The monoanionic complexes crystallise in at least two polymorphs, all of which have good cation and anion segregation in alternated layers, the anion layers making a dense 2D network of short S⋅⋅⋅S contacts. All of the neutral complexes, obtained as microcrystalline or quasi amorphous fine powder, present relatively large magnetic susceptibilities that correspond to effective magnetic moments in the range 1–3 μ B indicative of high spin states and very high electrical conductivity that in case of the Ni compound can reach σ RT ≈ 250 S cm −1 with a clear metallic behaviour. These compounds are new examples of the still rare single‐component molecular metals.