Enantiopure Conducting Salts of Dimethylbis(ethylenedithio)tetrathiafulvalene (DM‐BEDT‐TTF) with the Hexachlororhenate(IV) Anion

Abstract

The enantiopure radical cation salts [(S,S)‐DM‐BEDT‐TTF]4[ReCl6] ([(S,S)‐1]4[ReCl6]) and [(R,R)‐DM‐BEDT‐TTF]4[ReCl6] ([(R,R)‐1]4[ReCl6]) [DM‐BEDT‐TTF = dimethylbis(ethylenedithio)tetrathiafulvalene] have been prepared by electrocrystallization of the chiral precursor DM‐BEDT‐TTF in the presence of NBu4[ReCl5(pyrazine)] (NBu4 = tetra‐n‐butylammonium cation; pyz = pyrazine) as supporting electrolyte. The single‐crystal X‐ray analysis shows that the compounds crystallize in the triclinic system, non‐centrosymmetric space group P1, and that the donors arrange in parallel columns. The four independent donor molecules possess approximate charges of +1, +1/2, +1/2 and 0, according to the structural parameter analysis and band‐structure calculations, which also support the semiconducting behaviour of the materials. The rhenium(IV) ion in both compounds is six‐coordinate with six chloro atoms that describe a slightly distorted octahedral environment with Re–Cl distances that cover the short range 2.348–2.374 Å. Magnetic measurements on polycrystalline samples of [(S,S)‐1]4[ReCl6] and [(R,R)‐1]4[ReCl6] have been investigated in the temperature range 2–295 K. They are practically identical and confirm the presence of high‐spin S = 3/2 [ReCl6]2– isolated monomers together with a Pauli paramagnetism, typical of this kind of system. The magnetic susceptibility data are thoroughly reproduced over the whole temperature range with a simple model of isolated S = 3/2 ions with a zero‐field splitting plus a temperature‐independent paramagnetism (TIP), and the best‐fit parameters being gRe = 1.875(2), |D| = 4.50(3) cm–1 and TIP = 3630(20)×10–6 cm3 mol–1 (2D is the energy gap between the MS = ±3/2 and MS = ±1/2 Kramers doublets).

Enhancement of Intermolecular Magnetic Exchange through Halogen···Halogen Interactions in Bisadeninium Rhenium(IV) Salts

“…Anionic halorhenate(IV) salts are very appealing because of their unique magnetic properties, which include both slow relaxation and quantum tunneling of the magnetization and long-range magnetic order originating from single-ion or cooperative magnetic behaviours, respectively. [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] In particular, the simple hexahalorhenate(IV) salts [Re IV X6] 2-(X = F, Cl, Br, and I) of paramagnetic and diamagnetic cations generally show significant short-range intermolecular ferro-or antiferromagnetic interactions, which are mainly transmitted through relatively short intermolecular Re-X•••X-Re contacts, occasionally leading to collective magnetic phenomena such as ferromagnetism and spin canting (weak ferromagnetism). [47][48][49][50][51][52][53][54][55][56][57][58][59] Herein we report the synthesis and magneto-structural characterization of two novel Re IV compounds of general formula [H2ade]2[Re IV X6]X2•4H2O [H2ade 2+ = 9H-adenine-1,7-diium; X = Cl (1) and Br (2)].…”

Synthesis, crystal structure and magnetic properties of H2tppz[ReCl6] and [Cu(bpzm)2(μ-Cl)ReCl3(μ-ox)Cu(bpzm)2(μ-ox)ReCl3(μ-Cl)]n

“…These values correlate well with those reported in the literature for the related species incorporating the [ReCl 6 ] 2− unit (Table S3, ESI †). [1][2][3][4][5][6][7][9][10][11][12][13][14][15][16]56 The ReCl 6 octahedra form layers parallel to the bc plane, in which the neighboring [ReCl 6 ] 2− ions along the [010] direction show a different orientation as they are related by the twofold screw axis (2 1 ) operation. In the layer, the Re(IV) ions are thoroughly isolated from each other, with the shortest Re(1)⋯Re(1c) intralayer separation equal to 8.896 Å [symmetry code: (c) = 2 − x, −1/2 + y, 1/2 − z].…”

“…9,11,16,19 The magnetic properties of 2 in the form of χ M T against the T plot [χ M T is the magnetic susceptibility per Re IV 2 Cu II 2 unit] are shown in Fig. Leastsquares best-fit parameters resulting from the simultaneous analysis of the magnetic susceptibility and magnetization data by means of the XVPMAG programme 62 are: D Re = −15.8(2) cm −1 and g avRe = 1.85(1).…”

Magneto-structural correlations in a family of ReIVCuII chains based on the hexachlororhenate(iv) metalloligand

“…The [ReCl 6 ] 2− anion contains a slightly disordered octahedral geometry with Re-Cl bond lengths in the range 2.3457(5)-2.3859(4) Å, in accordance with previously published compounds containing this moiety (Tables S3 and S4 †). 5,7 The Cu II ion sits in a trans-X 4 Cl 2 coordination sphere (X = N (1-5) or O (6)) with the chloride ions positioned along the Jahn-Teller (JT) axis, with Cu-N bond lengths of 1.979(3)-2.017(2) Å for 1-5 and Cu-O bond lengths of 1.9450(16) and 1.9609(16) Å in 6 (Cu-O(2), Cu-O(1), respectively). Despite these similarities, the Cu-Cl bond lengths and the Re-Cl-Cu bond angles vary enormously, with Cu-Cl distances ranging between 2.78-3.23 Å, and the Re-Cl-Cu bond angles being as small as 128.6°and as large as 152.8° (Tables S3 and S4 †).…”

“…the effect of cation size on intermolecular interactions and T c ), the role of the [ReCl 6 ] 2− anion has been largely limited to that of synthetic precursor. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] Indeed, a common strategy for the creation of new Re IV complexes is the functionalisation of the [ReCl 6 ] 2− anion through halide exchange with ligands such as heterocyclic amines, pseudo halides such as cyanide, or chelates such as the oxalate anion. 6,[10][11][12][13] These species have subsequently been employed as metalloligands for the creation of larger oligomers.…”