Electronic switch of metal conductivity in μ6-carbon centered [Re12(μ6-C)S17(CN)6]n− nano cluster

The unique dodecanuclear cluster compounds M
_n
[Re
₁₂
(μ
₆
-C)S
₁₇
(CN)
₆
] (M-alkali metal; n=6, 8) were prepared and studied by cyclic voltammetry, solid-state high-resolution
¹³
C NMR and by density functional theory (DFT). The change of the anion redox state is accompanied by essential jump of distance between two {Re
₆
} subunits in a carbon-centered bioctahedral fragment [Re
₆
-C-Re
₆
] of the cluster. Switching of metal conductivity off and on is evidenced by giant change of
¹³
C NMR shielding that is typical for metal to insulator phase transitions.