Influence of H‐bonds on the Jahn–Teller Distortion in the Chain Structures of 2,2′‐bipyMn(H 2 PO 4 )F 2 ·H 2 O and 2,2′‐bipyMn(H 2 PO 4 ) 2 F

In the system 2,2′‐bipyridine/Mn III /HF/H 3 PO 4 /H 2 O two compounds with chain structures could be prepared and characterised by X‐ray structure analyses. 2,2′‐bipyMn(H 2 PO 4 )F 2 ·H 2 O ( 1 ): monoclinic, twinned, space group P 2 1 / c , Z = 4, a = 6.7883(4), b = 10.9147(5), c = 17.8102(8) Å, β = 100.142(4)°, R = 0.0328. 2,2′‐bipyMn(H 2 PO 4 ) 2 F ( 2 ): triclinic, space group P $\bar{1}$ , Z = 2, a = 6.675(1), b = 10.715(1), c = 11.013(1) Å, α = 107.595(9)°, β = 90.994(9)°, γ = 95.784(8)°, R = 0.0252. Both compounds show chain structures with trans‐ bridging dihydrogenphosphate ligands and bipy and two fluorine ligands for ( 1 ), or bipy, fluorine and an additional dihydrogenphosphate, respectively, for ( 2 ) in equatorial positions. Due to the pseudo‐Jahn–Teller effect, Mn III shows elongated octahedral coordination with ferrodistortive ordering along the chain direction. The distortion is remarkably higher in ( 1 ) than in ( 2 ). This is discussed in context with additional hydrogen bonds along the chain in ( 2 ).