ИСТИНА

The synthesis of multifunctional materials is one of the most important tendencies of modern science. At the same time, the creation of new multifunctional conductive materials, ranging from dielectrics and ending with superconductors, remains very actual, because different in their properties conductive materials are indispensable components of various micro- and macro electronic devices, that are used in all branches of engineering. In this respect, the molecular chemistry and molecular design are very promising directions, because they allow to obtain new materials that combine several (two or more) different physical properties. This is usually difficult or even impossible to achieve if it is, for example, homogeneous crystals or classic metals [G.Saito and Y. Yoshida, Frontiers of organic conductors and superconductors, in Unimolecular and supramolecular electronics I, ed. R.M. Metzger, Springer-Verlag, Berlin, 2012, 312, 67-126]. The search for new molecular systems that are able to form magnetically ordered systems is also of great interest [E. Coronado and P. Day, Magnetic molecular conductors, Chem. Rev., 2004, 104, 5419-5448]. Radical cation salts formed in the oxidation of tetrathiafulvalene derivatives cause the significant interest from the point of view of creating molecular conductive and magnetic materials with a wide range of electrical properties, from dielectric to superconductive, and also due to their possibility of generating magnetically ordered systems [J. Yamada and T. Sugimoto, TTF chemistry – fundamentals and applications of tetrathiafulvalene, Kodansha and Springer, Tokyo, 2004]. These compounds represent the hybrid systems consisting of several layers, one of which is the π-electrons donor that is responsible for conductivity and another one is acceptor charge-compensative anion. It should be noted, that the properties of such molecular conductors with the same cation depend mainly on the anionic part. Despite the fact that anionic part is not directly involved in the process of conduction, it plays the main role in the formation of radical-cations parking, that’s why the changes in the size, spatial orientation, volume and also in acceptor properties of counter ion, as a rule, lead to the significant changes in the electrical conductivity of compounds. In this respect, it is important to search for new hybrid molecular systems with various complementary of donor-acceptor layers to each other, that will allow obtaining conductive materials with desired properties. In addition, the introduction of transitional metals in anionic part can cause the magnetic moment that will allow getting compounds that combine conductive properties as well as magnetic ones. Previously it was shown that transitional metal bis(dicarbollides) [3,3’-M(1,2-C2B9H11)2]-, that can be easily modified by replacing of some hydrogen atoms to different functional groups, can be successfully used as an anionic component in radical cation salts on the base of tetrathiafulvalene and its derivatives. [V.I. Bregadze, O.A. Dyachenko, O.N. Kazheva, A.V. Kravchenko, I.B. Sivaev, V.A. Starodub, Tetrathiafulvalene-based radical cation salts with transition metal bis(dicarbollide) anions. CrystEngComm., 2015, 17, 4754-4767]. The scientific novelty of this work lies in the using of previously undescribed derivatives of transitional metal bis(dicarbollides) as charge-compensative anions. These compounds contain substituents in metallacarborane cluster that are able to stabilize certain rotational isomers (rotamers) and also to interact with the cationic sublattice, that will allow the direct influence on the lattice packing and therefore on the electrical and magnetic properties of the obtained materials. This study proposes to develop the synthetic methods and to synthesize several new derivatives of cobalt and iron bis(dicarbollides) with such substituents. The choice of cobalt bis(dicarbollide) is due to its diamagnetic nature and therefore the easiness of its study by NMR spectroscopy. At the same time the complexes of paramagnetic iron bis(dicarbollide) will allow getting materials with new magnetic characteristics.