BiZn Bond Formation in Liquid Ammonia Solution: [BiZnBi] 4− , a Linear Polyanion that is Iso(valence)‐electronic to CO 2

Reactions of the zinc(I) complex [Zn 2 (Mesnacnac) 2 ] (Mesnacnac=[(2,4,6‐Me 3 C 6 H 2 )NC(Me)] 2 CH) with solid K 3 Bi 2 dissolved in liquid ammonia yield crystals of the compound K 4 [ZnBi 2 ]⋅(NH 3 ) 12 ( 1 ), which contains the molecular, linear heteroatomic [BiZnBi] 4− polyanion ( 1 a ). This anion represents the first example of a three‐atomic molecular ion of metal atoms being iso(valence)‐electronic to CO 2 and being synthesized in solution. The analogy of the discrete [BiZnBi] 4− anion and the polymeric ${{{\hfill 1\atop \hfill \infty }}}$ [(ZnBi 4/2 ) 4− ] unit to monomeric CO 2 and polymeric SiS 2 is rationalized.