This review describes recent advances in the development of thiazyl radicals, particularly dithiadiazolyl (RCNSSN) and dithiazolyl (RCSNSCR) as molecule-based materials. Particular emphasis is placed on their potential applications as molecular conductors, magnets and switchable materials and incorporates an overview of the structure-property relationships required in these molecular systems.

A new dual-function hybrid molecular material has been obtained from the organic donor bis(ethylenedithio)tetraselenafulvalene and the honeycomb oxalate-based bimetallic network [MnCr(ox)3]-. This multilayer material consists of layers of the inorganic anionic 2D network, responsible for the appearance of ferromagnetic ordering below 5.3 K, alternating with segregated layers of the organic cation radical responsible for the transport properties: metal-like conductivity is observed from room temperature down to 150 K.

In 1928 Heisenberg proposed [1] that bulk ferromagnetic order would only ever be achieved in systems containing heavy atoms, that is, metals, their oxides, and related derivatives. Indeed it was not until 1991 that the first organic ferromagnet was reported; the b-polymorph of the para-nitrophenyl nitronyl nitroxide radical (p-NPNN, 1; Scheme 1) was shown to order below 0.6 K. [2] Since then a number of other purely organic radicals have been found to undergo bulk ferromagnetic order, although the majority order below 1 K. Exceptions include the radical cation salts [C 60 ][TDAE] [3] (TDAE = tetrakis(dimethylamino)ethylene) and [BBDTA]-GaCl 4 [4](3; BBDTA = benzobis(1,3,2-dithiazolyl), which order as ferromagnets at 16 and 6.7 K, respectively. Of the neutral radicals, only the nitroxide-based diradical DOTM-DAA (2; DOTMDAA = N,N'-dioxy-1,3,5,7-tetramethyl-2,6diazaadamantane) orders ferromagnetically above 1 K (T c = 1.48 K), [5] although the dithiadiazolyl radical p-NCC 6 F 4 CNSSNC (4) orders as a weak ferromagnet at 36 K under ambient pressure, [6] the highest reported temperature for magnetic ordering in an organic radical. We have sought to prepare new dithiadiazolyl radicals, closely related to 4, in which small structural changes may lead to new magnetically ordered systems. Here we report the structure and magnetic properties of 5, which is only the second neutral organic radical to order as a ferromagnet above 1 K.

Prussian blue (PB) represents a simple, economical, and eco-friendly system as cathode material for sodium-ion batteries (SIBs). However, structural problems usually worsen its experimental performance thus motivating the search for alternative synthetic strategies and the formation of composites that compensate these deficiencies. Herein, a straightforward approach for the preparation of PB/MoS 2 -based nanocomposites is presented. MoS 2 provides a 2D active support for the homogeneous nucleation of porous PB nanocrystals, which feature superior surface areas than those obtained by other methodologies, giving rise to a compact PB shell covering the full flake. The nanocomposite exhibits an excellent performance as cathode for SIBs with discharge capacity values up to 177 mA h g −1 and a specific capacitance of 354 F g −1 . These values are even larger for the intercalation of K + ions (up to 215 mA h g −1 , reaching a specific capacitance of 489 F g −1 ). Compared to similar composites, superior performance can be ascribed to a synergistic effect of the coordination compound with the 2D material.

The intramolecular magnetic exchange coupling constants (J) for a series of tetrathiafulvalene (TTF) and verdazyl diradical cations connected by a range of pi conjugated linkers have been investigated by means of methodology based on unrestricted density functional theory. The magnetic interaction between radicals is transmitted via pi-electron conjugation for all considered compounds. The calculation of J yields strong or medium ferromagnetic coupling interactions (in the range of 56 and 300 K) for diradical cations connected by linkers with an even number of carbon atoms that are able to provide a spin polarization pathway, while antiferromagnetic coupling is predicted when linkers with an odd number of carbon atoms are employed. The topological analysis of spin density distributions have been used to reveal the effects of the spin polarization on both linkers and spin carriers. The absence of heteroatoms that impede the spin polarization pathway, and the existence of a unique spin polarization path instead of several possible competitive routes are factors which contribute to large positive J values favoring ferromagnetic interactions between the two terminal pi-radicals. The magnitude of J depends strongly on the planarity of the molecular structure of the diradical cation since a more effective orbital overlap between the two pi-systems can be achieved. Hence, the dependence of J on the torsion angle (theta) of each spin carrier has been analyzed. In this respect, our findings show that this geometrical distortion reduces largely the calculated J values for ferromagnetic couplings, leading to weak antiferromagnetic interactions for a torsion angle of 90 degrees .