Supramolecular approach to the synthesis of [60]fullerene-metal dithiocarbamate complexes, {(M-II(R(2)dtc)(2))(x)center dot L}center dot C-60 (M = Zn, Cd, Hg, Fe, and Mn; x=1 and 2). The study of magnetic properties and photoconductivity

摘要

Coordination assemblies formed by metal(II) dithiocarbamates M-II(R(2)dtc)2 (M = Zn, Cd, Hg, Mn, and Fe; R = Me, Et, iPr, nPr, and nBu) and nitrogen-containing ligands (L = DABCO, DMP, and HMTA) are shown to be sterically well consistent with the spherical shape of fullerenes and are effectively cocrystallized with them to form complexes {(M-II(R(2)dtc)(2))(x)center dot L}center dot C-60 (x = 1 and 2) with layered or three-dimensional (31)) packing of fullerene molecules (1-11). For the first time the molecular structures of the M-II(R2dtc)2 assemblies in the complexes with C60 are presented (including those with M = Mn, Fe, and Hg). According to optical and electron paramagnetic resonance (EPR) spectroscopy 1-11 have a neutral ground state. Magnetic susceptibilities of {[M-II(Et(2)dtc)(2)](2)center dot DABCO}center dot C-60 center dot(DABCO)(2) (M = Mn and Fe) follow the Curie-Weiss law in the 50-300 K range with the Weiss constants Theta = 0.35 and 1.70 K, respectively. Magnetic moments of the complexes equal to 8.23 and 6.88 mu(B) at 300 K correspond to the high-spin state of the Mn-II (S = 5/2) and Fe-II (S = 2) ions. The increase of mu(eff) observed below 35 and 50 K up to 8.5 mu(B) (at 3 K) and 7.4 mu(B) (at 6 K) indicates the manifestation of short-range ferromagnetic interactions between M-II spins in the isolated [M-II(Et(2)dtc)(2)](2)-DABCO dimers. Under illumination by white light, the complexes show up to 102 times increase of photocurrent. The main contribution to the generation of free charge carriers is provided by direct charge transfer from {M-II(R(2)dtc)(2)}(2)center dot L to C-60. It was found that photocurrent increases in magnetic field with induction B < 1T.