Syntheses and Crystal Structures of Two Cobalt Carboxylate−Phosphonates with 4,4′‐Bipyridine as a Secondary Metal Linker

The hydrothermal syntheses and crystal structures of two novel cobalt carboxylate−phosphonates with 4,4′‐bipyridine (4,4′‐bipy) as the secondary metal linker are reported. Compound 1 , [Co 3 (H 2 L) 2 (H 2 O) 4 (4,4′‐bipy)], where H 5 L = 4‐HO 2 CC 6 H 4 CH 2 N(CH 2 PO 3 H 2 ) 2 , crystallizes in the monoclinic space group C 2/ c with a = 25.9281(5), b = 9.76310(10), c = 17.3671(5) Å, β = 103.290(2)°, V = 4278.6(2) Å 3 , and Z = 4. Its structure contains a pillar‐layered architecture in which Co II octahedra are linked by carboxylate−phosphonate ligands to form a 2D layer and these layers are crosslinked further by 4,4′‐bipy ligands to form a porous 3D network. Compound 2 , [Co 2 (PMIDA)(H 2 O) 5 (4,4′‐bipy)]·4H 2 O, where H 4 PMIDA = H 2 O 3 PCH 2 N(CH 2 CO 2 H) 2 , crystallizes in the triclinic space group P $\bar 1$ with a = 7.8009(7), b = 13.4560(12), c = 13.5453(12) Å, α = 65.207(2), β = 88.035(2), γ = 77.135(2)°, V = 1255.57(19) Å 3 , and Z = 2. The crystal structure of compound 2 contains 1D zigzag chains in which two cobalt( II ) ions are bridged by PMIDA ligand to form dimeric units, and these dimeric units are connected further by bridging 4,4′‐bipy ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)