New charge transfer salts of two organic π-donors of the tetrathiafulvalene type with the paramagnetic [Cr(NCS)6]3– anion

Abstract

The electrochemical combination of the paramagnetic anion [Cr(NCS) 6 ] 3with the organic p-donors bis(ethylenedithio)tetrathiafulvalene (ET) and 4,5-bis(2-hydroxyethylthio)-4',5'-ethylenedithiotetrathiafulvalene (DHET-EDTTTF) leads to two new radical cation salts, namely (ET) 4 [Cr(NCS) 6 ]•PhCN (1) and (DHET-EDTTTF) 2 (NEt 4 )[Cr(NCS) 6 ] (2). Both have been characterized by X-ray crystallography, magnetic and resistivity measurements. The structure of 1 consists of alternating inorganic layers generated by the anions and organic layers in which the PhCN molecules are inserted; the organic sub-lattice is built up from four different ET units, three of them with a charge distribution of +1, the fourth being neutral. The organic sub-lattice of 2 contains a centrosymmetric [(DHET-EDTTTF • ) 2 ] 2+ dimer, in which the overlap mode is of the eclipsed type. Conductivity measurements indicate that compounds 1 and 2 are semiconductors with room temperature conductivities of 1.4 × 10 -2 and 6.1 × 10 -5 S cm -1 and activation energies of 0.24 and 0.23 eV, in 1 and 2, respectively. For both salts, magnetic measurements indicate (i) that the organic and inorganic parts are magnetically independent, and (ii) that the organic units are antiferromagnetically coupled. To cite this article: F.

Structural diversity in charge transfer salts based on Mo3S7 and Mo3S4Se3 clusters complexes and bis(ethylenedithio)tetrathiafulvalene (ET)

“…The use of anionic complexes containing sulfur, selenium or halogens is preferred because of the relevance of Y-(S/H) (Y = Cl, Br, I, S, Se) intermolecular contacts between the inorganic and organic components. Numerous examples including either mono-or polynuclear complexes have been successfully employed in the preparation of charge transfer salts such as for example the anions [M(NCS) 6 ] 32 (M = Fe, Cr), 4,5 the halide complexes [MCl 4 ] n2 (M = Zn, Mn, Ga, Fe) [6][7][8][9][10] and [Nb 6 Cl 18 ] 32 , 11 or the chalcogenide and halidecontaining clusters [Re 6 Q 6 Cl 8 ] 22 (Q = S, Se) [12][13][14][15] and [Mo 3 S 7 Br 6 ] 22 . 16 Another class of versatile acceptor molecules are the metal dithiolene complexes.…”

High Surface Area of Polyhedral Chromia and Hexagonal Chromium Sulfide by the Thermolysis of Cyclohexylammonium Hexaisothiocyanatochromate(III) Sesquihydrate

“…[34,44,57,85,86] Furthermore, structural studies by single X-ray diffraction confirmed the binding of N-terminal to Cr(III) in [Cr(NCS) 6 ] 3À . [21,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][39][40][41][42][43][44][45][46][47][48][49] The asymmetric stretching vibration of (À NH + 3 ) bonds of cyclohexylammonium cation could be assigned to the strong, broad bands in the range of 3300-3000 cm À l . This red shift in the asymmetric stretching of NÀ H could be due to the positive charge borne by the nitrogen atom and the hydrogen bonding to the water crystallization molecules and to the S-terminals of [Cr(NCS) 6 ] 3À anion.…”

“…[21] Among the thiocyanate metal complexes is the anionic complex of hexaisothiocyanatochromate(III) [Cr-(NCS) 6 ] 3À , which was used broadly to construct various supramolecular structures with either organic cations [22][23][24][25][26][27][28][29][30] or metal cations, [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] partially, because both of thiocyanate nitrogen and sulfur terminals are hydrogen acceptors when forming hydrogen bonds. [14,20,25,[27][28][29][31][32][33][34][35][36][37][39][40][41][42][43][44][45]…”

“…[25] For instance, when the paramagnetic anion of [Cr(NCS) 6 ] 3À was combined with charge-transfer organic π-donors of tetrathiafulvalene derivatives, the resultant salts were paramagnetic semiconductors due to their layered structures, which were composed of isolated organic cations and inorganic anions without contacts except the weak S⋅⋅⋅S contacts between cation and anion, and thereby, lack of magnetic exchange interactions. [24,26,27,30] The metal salts of [Cr(NCS) 6 ] 3À are classified as bimetallic complexes or double complex salts. [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] They are able to form molecular magnets.…”

Electrochemical and atomic force microscopy investigations of new materials from N-trifluoromethanesulfonyl-1-azahexa-1,3,5-trienes derivatives

“…10,11 In this work, the in situ film formation of novel compounds on the surface of high oriented pyrolytic graphite (HOPG) electrodes was performed by using a combined technique based on electrochemistry and atomic force microscopy (EC-AFM). The films morphology and composition was studied with atomic force microscopy, scanning electron microscopy and energy dispersive spectroscopy.…”