Hybridized complexes of [MnIII2] single-molecule magnets and Ni dithiolate complexes

The electrochemical oxidation of an acetone solution or acetonitrile (MeCN) solution containing [MnIII2(5-MeOsaltmen)2(H2O)2](PF6)2 (5-MeOsaltmen2− = N,N′-(1,1,2,2-tetramethylethylene)bis(5-methoxysalicylideneiminate)) and (NBu4)[Ni(dmit)2] (dmit2− = 2-thioxo-1,3-dithiole-4,5-dithiolate) has yielded two unique hybrid materials in which [Mn2]2+ single-molecule magnets (SMMs) possessing an ST = 4 ground state and [Ni(dmit)2]n− molecules each possessing an average valence of ca.−0.29 are aggregated in a layer-by-layer form; [Mn2(5-MeOsaltmen)2(acetone)2][Ni(dmit)2]7 · 4acetone (1) and [Mn2(5-MeOsaltmen)2(MeCN)2][Ni(dmit)2]7 · 4MeCN (2).Compounds 1 and 2 have a similar structure to each other and crystallize in the triclinic P1¯ space group with inversion centers on the midpoint of Mn⋯Mn vector of the dimer and a Ni ion of one of [Ni(dmit)2]0.29− molecules (i.e., Z = 1).The [Mn2]2+ unit has a typical Mn(III) out-of-plane dimeric core and is structurally consistent with the already reported [Mn2] SMMs.Seven [Ni(dmit)2]0.29− units in the formula have a square-planar coordination geometry in common, and the charge distribution among them can be averagely assigned according to their local structures and IR spectra; thus, the formal charge for each molecule is −0.29.These two kinds of molecules,[Mn2]2+ SMM units and [Ni(dmit)2]0.29− units, construct hybrid frames aggregating individually, where the latter units form a β-type stacking arrangement. Electronic conductivity measurements revealed that 1 and 2 are semiconductors with σrt = 1.6 S cm−1 and 2.8 S cm−1, respectively, at room temperature. The detail magnetic measurements proved that the [Mn2]2+ units in 1 and 2 behave as ST = 4 SMMs at low temperatures, although their conductivities are already insulated at such temperatures.

Graphical abstractThe electrochemical oxidation of an acetone or acetonitrile solution containing a Mn(III) salen-type out-of-plane dimer and (NBu4)[Ni(dmit)2] has yielded two unique hybrid materials, in which [Mn2]2+ single-molecule magnets (SMMs) possessing an ST = 4 ground state and [Ni(dmit)2]n− molecules each possessing an average valence of ca.−0.29, are aggregated in a layer-by-layer form, exhibiting SMM/semiconductor behavior.Figure optionsDownload full-size imageDownload as PowerPoint slide