Hybrid molecular material exhibiting single-molecule magnet behavior and molecular conductivity

Two unique materials based on Mn-4 single-molecule magnet (SMM) clusters (S-T = 9) and integer or non-integer average valent platinum maleonitriledithiolate (mnt(2-)) complexes, [{(Mn2Mn2III)-Mn-II(hmp)(6)(MeCN)(2)}{Pt(mnt)(2)}(2)][Pt(mnt)(2)](2)center dot 2MeCN (1) and [{(Mn2Mn2III)-Mn-II(hMP)(6)(MeCN)(2)}{Pt(mnt)(2)}(4)][Pt(mnt)(2)](2) (2), were synthesized by the material diffusion method and electrochemical oxidation, respectively (hmp(-) = 2-hydroxymethylpyridinate). 1 and 2 are comprised of four and six [Pt(mnt)(2)](n-) units, respectively, in addition to a common (Mn2Mn2III)-Mn-II double-cuboidal unit, [Mn-2(II)-Mn (III)(2)(hmP)(6)(MeCN)(2)](4+) (hereinafter [Mn-4](4+)). Among the [Pt(mnt)(2)](n-) units, two units in 1 and four units in 2 are coordinated with the [Mn-4](4+) unit, forming a 1D chain of {-[Mn-4]-[Pt(mnt)(2)](2)-} for 1 and a discrete subunit of [Pt(mnt)(2)](2)-[Mn-4]-[Pt(mnt)(2)](2)} for 2. The other two [Pt(mnt)(2)](n-) units, occupying void space of the packing, form a stacking column with the coordinating [Pt(mnt)(2)](n-) units, finally constructing hybrid frames of aggregates consisting of [Mn-4](4+) units and [Pt(mnt)(2)](n-) units. Electronic conductivity measurements revealed that 1 is an insulator and 2 is a semiconductor with sigma = 0.22 S center dot cm(-1),at room temperature and an activation energy of 136 meV. Detailed magnetic measurements proved that the [Mn-4](4+) units in 1 and 2 behave as SMMs with an S-T = 9 ground state at low temperatures. There is no significant interaction between [Mn-4](4+) units and [Pt(mnt)(2)](n-) units, but interactions between localized spins of [Pt(mnt)(2)](n-) were detected even in 2 at low temperatures where the conductivity is electronically insulated. 2 is the first example of a hybridized material exhibiting SMM behavior and electronic conductivity.