Asymmetrical Platinum and Rhodium Dinuclear Complex Strongly Bound to Filled d z 2 ${{_{{\rm z}{^{2}}}}}$ Complexes by Unbridged Pt-Metal Bonds: Toward Heterometallic-Extended Metal Atom Chains.

Heterometallic extended metal atom chains (EMACs) aligned with three types of metal were rationally synthesized by forming unbridged metal-metal bonds based on the interactions between highest occupied and lowest unoccupied molecular orbitals at the d z 2 ${{_{{\rm z}{^{2}}}}}$ orbital. These chains form pentanuclear structures aligned as Rh-Pt-M-Pt-Rh with relatively large formation constants of 5.0×10 13  M -2 for M=Pt and 6.3×10 11  M -2 for M=Pd, while retaining their backbones in solution. In the case of M=Cu, the original Cu(+2) atoms were reduced to Cu(+1) during the synthetic process. Cu(+1) has an unprecedented trigonal bipyramidal coordination geometry. The reported synthesis based on asymmetrical dinuclear complexes provides a guideline for the synthesis of hetero-EMACs to allow several analogs through judicious combinations realized by tuning the number of metal nuclei and metal species.