A charge‐separation‐type ionic solid composed of hexanuclear complexes with a macrocyclic tetragold(I) metalloligand

The reaction of Na[CoIII(d‐ebp)] (d‐H4ebp = N,N′‐ethylenebis[d‐penicillamine]) with [(AuICl)2(dppe)] (dppe = 1,2‐bis[diphenylphosphino]ethane) gave a cationic AuI4CoIII2 hexanuclear complex, [CoIII2(LAu4)]2+ ([1]2+), where [LAu4]4− is a cyclic tetragold(I) metalloligand with a 32‐membered ring, [AuI4(dppe)2(d‐ebp)2]4−. Complex [1]2+ crystallized with NO3− to produce a charge‐separation (CS)‐type ionic solid of [1](NO3)2. In [1](NO3)2, the complex cations are assembled to form cationic supramolecular hexamers of {[1]2+}6, which are closely packed in a face‐centered cubic (fcc) lattice structure. The nitrate anions of [1](NO3)2 were accommodated in hydrophilic and hydrophobic tetrahedral interstices of the fcc structure to form tetrameric and hexameric nitrate clusters of {NO3−}4 and {NO3−}6, respectively. An analogous CS‐type ionic solid formulated as [NiIICoIII(LAu4)](NO3) ([2](NO3)) was obtained when a 1:1 mixture of Na[CoIII(d‐ebp)] and [NiII(d‐H2ebp)] was reacted with [(AuICl)2(dppe)], accompanied by the conversion of the diamagnetic, square‐planar [NiII(d‐H2ebp)] to the paramagnetic, octahedral [NiII(d‐ebp)]2−. While the overall fcc structure in [2](NO3) was similar to that of [1](NO3)2, none of the nitrate anions were accommodated in any hydrophobic tetrahedral interstice, reflecting the difference in the complex charges between [1]2+ and [2]+. A cationic AuI4CoIII2 complex ([1]2+) containing CoIII centers that are surrounded by a tetragold(I) metalloligand with a 32‐membered ring was newly synthesized. [1]2+ crystallized with NO3− to construct a CS‐type ionic solid, in which cations of [1]2+ are assembled in supramolecular hexamers that are closely packed in a fcc lattice structure. An analogous CS‐type ionic solid containing both NiII and CoIII centers is also reported.