From a 1D Sb Coordination Polymer to a 3D Sb Framework with Pyrazine: Switching off the Stereochemically Active Lone‐Pair

The one‐dimensional coordination polymer 1 ∞ [SbCl 3 (pyz)] ( 1 ) and the three‐dimensional frameworks 3 ∞ [Sb 2 Cl 6 (pyz) 3 ] ( 2 ) and 3 ∞ [Sb 2 I 6 (pyz) 3 ] ( 3 ) were obtained from SbX 3 (X: Cl, I) and pyrazine (pyz). These coordination polymers are, to the best of our knowledge, among the first Sb‐based coordination polymers constructed from antimony halides and N‐donor ligands. While the Sb 3+ ‐cations in 1 are coordinated in a square‐pyramidal coordination sphere indicating a stereochemically active lone‐pair, no stereochemically active Sb‐lone‐pair is present in 2 and 3 having octahedral coordination spheres around Sb III . Since 2 can be obtained by heating of 1 , the character of the Sb‐lone‐pair in 1 can be changed by thermal treatment. Thereby the interlinkage is increased via an additional pyrazine molecule resulting in the octahedral coordination in 2 .