A >22Å long metal-complex anion and a 1D cationic coordination polymer, both based on 4,4′-bipyridine- N , N ′-dioxide, yielding a 3D and 2-fold interpenetrated fsc net of the hydrogen-bonded metal-organic 1D polymer

Abstract The cationic one-dimensional (1D) coordination polymer chain 1 ∞ {[Co(μ-bpdo)(H 2 O) 4 ] 2+ } and the metal-complex anion trans -[Co(SO 4 ) 2 (bpdo) 2 (H 2 O) 2 ] 2− , both based on the 4,4′-bipyridine- N , N ′-dioxide (bpdo) ligand, form a complementary supramolecular pair 1 ∞ {[Co(μ-bpdo)(H 2 O) 4 ] 2+ } n n [Co(SO 4 ) 2 (bpdo) 2 (H 2 O) 2 ] 2− ( 1 ) with respect to charge balance and hydrogen bonding. With a length of >22.14 Ǻ along the bpdo–Co–bpdo axis the metal-complex trans -[Co(SO 4 ) 2 (bpdo) 2 (H 2 O) 2 ] 2− is one of the longest and anisotropic counter anions (aspect ratio 22.14:8.11:4.17) observed so far in coordination polymers. Hydrogen-bonding of the anion links the cationic metal-organic 1D polymer into a 2-fold interpenetrated three-dimensional (3D) fsc (or sqc11) 4,6-c 2-nodal net of stoichiometry (4-c)(6-c) with square-planar, 4-connected (Co in anion) and octahedral, 6-connected (Co in cation) nodes in a 1:1 ratio. The 4-c point symbol is (4 4 .6 2 ), the 6-c one (4 4 .6 10 .8) yielding a point symbol for the fsc net of (4 4 .6 2 )(4 4 .6 10 .8). The synthesis of 1 requires the presence of a Schiff base. Synthesis under the same conditions in the absence of the Schiff base yields the molecular complex and cocrystal [Co(bpdo)(H 2 O) 5 ]SO 4 ·1/2bpdo ( 2 ) which is related (as pseudo-polymorph) to the known solvate [Co(bpdo)(H 2 O) 5 ]SO 4 ·2H 2 O ( 3 ) (CSD Refcodes RAXMUZ and RAXMUZ01).