Molecular magnetic semiconductors formed by cationic and anionic networks: (ET)2Mn[N(CN)2]3 and (ET)2CuMn[N(CN)2]4

Abstract

Crystals of (ET) 2 Mn[N(CN) 2 ] 3 (1) and (ET) 2 CuMn[N(CN) 2 ] 4 (2) with mono-and first bimetal dicyanamide anions were obtained and their structure, conducting and magnetic properties were investigated. The structure of 2 is not typical for ET radical cation salts and is characterized by the presence of a 3D polymeric anion built into the ET radical cation layers. The crystals of 1 exhibit a semiconducting behavior of conductivity and 2 undergoes a semiconductor I-semiconductor II phase transition at 295-291 K, which is specified by a jump of resistivity and the appearance of a hysteresis in the R(T) curves. The phase transition is accompanied by changes in the charge state of the ET molecules and intermolecular interactions in the crystal. Antiferromagnetic correlations of spins associated with anionic subsystems were found in both salts at temperatures lower than 25 K. Antiferromagnetic ordering in 1 has a long-range character. The effect of the spin frustrated state of localized spins on conducting electrons of ET subsystem was found in 1.

The first polymorph, κ″-(ET)2Cu[N(CN)2]Cl, in the family of κ-(ET)2Cu[N(CN)2]X (X=Cl, Br, I) radical cation salts

“…When the Co[N(CN) 2 ] 2 Á H 2 O salt in 1.1.2-trichloroethane was employed as electrolyte, crystals of ET 3 CoCl 4 and ET 3 Cl 2 Á 2H 2 O were formed (the compositions of the salts ET 3 CoCl 4 and ET 2 CuCl 2 were determined by using energy dispersion X-ray spectroscopy and X-ray analysis, respectively). The combination of two salts Mn[N(CN) 2 ] 2 and CuCl as electrolyte yielded the ET 2 CuMn[N(CN) 2 ] 4 and ET 2 CuCl 2 crystals [30]. We studied the electrochemical oxidation of ET in the presence of a mixed electrolyte including Co[N(CN) 2 ] 2 and CuCl and obtained two types of crystals.…”

“…When using a Mn salt instead of the Cu one crystals of ET 2 Mn[N(CN) 2 ] 3 were obtained [29,30]. When the Co[N(CN) 2 ] 2 Á H 2 O salt in 1.1.2-trichloroethane was employed as electrolyte, crystals of ET 3 CoCl 4 and ET 3 Cl 2 Á 2H 2 O were formed (the compositions of the salts ET 3 CoCl 4 and ET 2 CuCl 2 were determined by using energy dispersion X-ray spectroscopy and X-ray analysis, respectively).…”

“…Compound k 00 -Cl k 0 -Cl [13] k-Cl [13] Crystal system Monoclinic Orthorhombic 30.420 (7) 12.963 (2) 12.963 (2) showed that one type of crystals (strips-like crystals) are those of the already known radical cation salt ET 2 CuCl 2 [23], while the other (rhombus-like crystals) have the same composition, (ET) 2 Cu[N(CN) 2 ]Cl, of the k-Cl and k 0 -Cl salts. As it is the case for these two salts, it is characterized by a k-type arrangement of the ET conducting layers but now the structure is monoclinic, in contrast with the orthorhombic structure of the k-and k 0 -Cl salts (see Table 1).…”

Effect of Mn2+ spin frustrations on spin dynamics of charge carriers in (BEDT‐TTF)2Mn[N(CN)2]3 crystals

“…1) are described in [15,16], in which the contributions of BEDT-TTF and Mn to the electron spin resonance (ESR) signal are distinguished and recognized.…”

“…Recently the synthesis and magnetic properties of a new spin-frustrated compound (BEDT-TTF) 2 Mn[N(CN) 2 ] 3 have been reported [14][15][16]. The Mn[N(CN) 2 ] 3 complexes forming a triangular planar lattice ( Fig.…”