A Spin-Frustrated Azide- and Alkoxide-Bridged Heterobimetallic Mixed-Valence Mn II Mn III 2 Ni II 4 Disc with S = 17/2 or 19/2.

Seven-membered homometallic Fe III 7 , Mn III 3 Mn II 4 coordination clusters were previously reported to be spin-frustrated molecular discs. Herein, a mixed bimetallic and mixed-valence dicationic [Mn II Mn III 2 Ni II 4 (N 3 ) 4 (hmp) 10 ](NO 3 ) 2 ( 1 2+ (NO 3 ) 2 ) was isolated in pure form without scrambling of Ni/Mn ions. It was structurally characterized by single-crystal X-ray single-crystal diffraction. The presence of Mn II ions at the center of the disc has been confirmed by EPR measurements. The magnetic studies suggest that complex 1 2+ (NO 3 ) 2 possesses spin frustration with spin ground states S = 17/2 and 19/2, which has been studied and supported by DFT calculation. The purity of 1 2+ (NO 3 ) 2 was confirmed by powder XRD measurements, and the ratio of Ni:Mn = 4:3 was further determined by SEM-EDX analysis.