Mixed-Valence Conductors from Ni Bis(diselenolene) Complexes with a Thiazoline Backbone

Abstract

Highly conducting, mixed-valence, multi-component nickel bis(diselenolene) salts were obtained by electrocrystallization of the monoanionic species [Ni(Me-thiazds)2]−1 (Me-thiazds: N-methyl-1,3-thiazoline-2-thione-4,5-diselenolate), with 1:2 and 1:3 stoichiometries depending of the counter ion used (Et4N+ and nBu4N+ vs Ph4P+, respectively). This behavior strongly differs from that of the corresponding monoanionic dithiolene complexes whose oxidation afforded the single component neutral species. This provides additional rare examples of mixed-valence conducting salts of nickel diselenolene complexes, only known in two examples with the dsit (1,3-dithiole-2-thione-4,5-diselenolate) and dsise (1,3-dithiole-2-selone-4,5-diselenolate) ligands. The mixed-valence salts form highly dimerized or trimerized bi- and trimetallic units, rarely seen with such nickel complexes. Transport measurements under a high pressure (up to 10 GPa) and band structure calculations confirm the semiconducting character of [Ph4P][Ni(Me-thiazds)2]3 and the quasi metallic character of [Et4N][Ni(Me-thiazds)2]2 and [NBu4] x [Ni(Me-thiazds)2]2 salts (0 < x < 1).

Structure–activity relationship of anticancer and antiplasmodial gold bis(dithiolene) complexes

“…12 Actually, in this series only AuS-tBu exhibited a cyclic voltammogram similar to that of the complexes with a long alkyl chain. 29 The reversible systems obtained suggests that AuS-C 12 and AuS-PEG are less susceptible to settles on the electrode surface as it was observed for the gold complexes belonging to the same series with shorter alkyl chain (Fig. S1 and S2 †).…”

A highly conducting mixed-valence nickel bis(dithiolene) salt [Et4N][Ni(Me-thiazSe-dt)2]2 with selone substitution

“…This substitution offers a rich palette of modifications of the dmit motif, by allowing a variety of R substituents on the nitrogen atom. 19 Also these [M(R-thiazdt) 2 ] 1− complexes are known to systematically oxidize at lower potentials than their dmit counterparts and in most cases the oxidation of the nickel or gold R-thiazdt monoanionic complexes doesn't afford mixed-valence salts but the neutral complexes, either the closed-shell nickel [Ni(R-thiazdt) 2 ] 0 species 20 23 In that respect, introduction of the selone functionality in the R-thiazdt family to give the [M(R-thiazSe-dt) 2 ] complexes (Chart 1), would combine the flexibility introduced by the R substituent on the nitrogen atom of R-thiazdt complexes with the possibility for extended intermolecular interactions observed earlier in dmiSe complexes. [15][16][17] Only two such [M(R-thiazSe-dt) 2 ] complexes have been reported earlier.…”

“…Rare examples of mixed-valence derivatives have been recently reported in R-thiazoline- diselenolene (R-thiazds) complexes such as [Ph 4 P][Au(Me-thiazds) 2 ] 2 , 22 or [Et 4 N][Ni(Me-thiazds) 2 ] 2 . 23 In that respect, introduction of the selone functionality in the R-thiazdt family to give the [M(R-thiazSe-dt) 2 ] complexes (Chart 1), would combine the flexibility introduced by the R substituent on the nitrogen atom of R-thiazdt complexes with the possibility for extended intermolecular interactions observed earlier in dmiSe complexes. 15–17…”

Cyano benzene functionalised Ni and Cu bisdithiolene complexes

“…2 More recently, some of these complexes have exhibited high electrical conductivity and true metallic properties in their neutral state. [17][18][19][20][21][22][23][24] Previously we reported the synthesis of two distinct families of cyano benzene-functionalized transition metal bisdithiolene complexes [M(dcbdt) 2 ] Z− (ref. 25 and 26) and the [M(4cbdt) 2 ] Z− (ref.…”

“…2 More recently, some of these complexes have exhibited high electrical conductivity and true metallic properties in their neutral state. 17–24…”