Cadmium and zinc chain and cluster-based layered coordination polymers prepared from flexible-arm aromatic ortho-dicarboxylic acids and 4-pyridylnicotinamide

Abstract Hydrothermal reaction of a d 10 -metal nitrate salt, a flexible-arm aromatic ortho -dicarboxylic acid, and 4-pyridylnicotinamide (4-pna) afforded four new crystalline coordination polymers, which were characterized by single-crystal X-ray diffraction. [Cd(Hhmph)(nic)(H 2 O) 2 ] n ( 1 , hmph = homophthalate, nic = nicotinate) is a 1-D coordination polymer chain compound whose nic ligands were generated in situ via 4-pna hydrolysis. Addition of base and a shorter reaction duration afforded [Cd(hmph)(4-pna)] n ( 2 ), which has dinuclear [Cd 2 (hmph) 2 ] dimers linked into a 1-D ladder polymer via 4-pna ligands. A similar chain structure, albeit with a different hmph binding mode, is seen in [Zn(hmph)(4-pna)] n ( 3 ). {[Zn 2 (phda) 2 (4-pna) 2 (H 2 O)]⋅H 2 O} n ( 4 , phda = 1,2-phenylenediacetate) has both anti-syn bridged [Zn 2 (OCO) 2 ] ring dimers and [Zn 2 (OCO) 4 ] paddlewheel dimers, linked into a layered coordination polymer by dipodal 4-pna ligands. Luminescent properties of these new materials are also presented.