Electrical Conductivity and Spin Crossover:  A New Achievement with a Metal Bis Dithiolene Complex

Abstract

Three new compounds based on the cationic complex [Fe(III)(3-R-salEen)(2)]+ (salEen stands for N-(2-ethylamino)ethyl)-salicylaldimine, R = H, CH(3)O) with the electroactive Ni(dmit)(2) species as a counterion (dmit stands for 1,3-dithia-2-thione-4,5-dithiolato) have been synthesized and structurally and magnetically characterized. Compound 1 ([Ni(dmit)(2)][Fe(3-OMe-salEen)(2)]. CH(3)OH) shows an apparent hysteresis loop, due to an irreversible desolvatation process. Compound 2 ([Ni(dmit)(2)](NO(3))[Fe(salEen)(2)](2)) exhibits a gradual and incomplete spin transition. Compound 3 ([Ni(dmit)(2)](5)[Fe(salEen)(2)](2), 6CH(3)CN) is a fractional oxidation state complex, which behaves like a semiconductor and exhibits a gradual but complete spin transition between 300 and 4 K.

Charge Transport and Electrical Properties of Spin Crossover Materials: Towards Nanoelectronic and Spintronic Devices

“…Hybrid materials containing SCO complexes as well as conducting molecular species in the same crystal lattice were reported by several teams [40][41][42][43][44][45][46][47][48][49][50][51][52]. Most of these compounds exhibit either SCO or semiconducting behavior or both at the same time, but (in our opinion) a clearly discernible interplay between the two phenomena has been achieved only in two cases.…”

The Highly Conducting Spin-Crossover Compound Combining Fe(III) Cation Complex with TCNQ in a Fractional Reduction State. Synthesis, Structure, Electric and Magnetic Properties

“…The interplay between spin-crossover and conductivity was already observed in some of such materials [17,[29][30][31][32][33]. The most of conducting SCO compounds represent the Fe(III) cation complexes with [M(dmit) 2 ] δ− anions [29,30,[34][35][36][37][38]. There is only one compound with TCNQ δ− , described in publications: [Fe(III)(acpa) 2 ](TCNQ) 2 , with σ rt = 2.8 10 −3 Ω −1 ·cm −1 [39].…”

Temperature and pressure effects on the spin state of ferric ions in the [Fe(sal2-trien)][Ni(dmit)2] spin crossover complex

“…Combining SC and electrical conductivity was the aim of Dorbes et al [11] [12]. Analogously, similar properties have been studied on the salts of the [Fe(qsal) 2 ] + and Fe(R-salEen)] + complex cations as well [13][14][15][16][17][18][19].…”