Substituent dependent dimensionalities in cobalt isophthalate supramolecular complexes and coordination polymers containing dipyridylamine ligands

Abstract

Hydrothermal synthesis has afforded cobalt 5-substituted isophthalate complexes with 4,4′-dipyridylamine (dpa) ligands, showing different dimensionalities depending on the steric bulk and hydrogen-bonding facility of the substituent. [Co( tBuip)(dpa)(H 2O)] n ( 1, tBuip = 5- tert-butylisophthalate) is a (4,4) grid two-dimensional coordination polymer featuring 2-fold parallel interpenetration. [Co(MeOip) 2(Hdpa) 2] ( 2, MeOip = 5-methoxyisophthalate) is organized into 3-fold parallel interpenetrated (4,4) grids through strong N–H +⋯O − hydrogen bonding. {([Co(OHip)(dpa)(H 2O) 3]) 3·2H 2O} n ( 3, OHip = 5-hydroxyisophthalate) possesses 1-D chain motifs. The 5-methyl derivative {[Co(mip)(dpa)]·3H 2O} n ( 4, mip = 5-methylisophthalate) has a 3-D 6 58 cds topology. {[Co(H 2O) 4(Hdpa) 2](nip) 2·2H 2O} ( 5, nip = 5-nitroisophthalate) and {[Co(sip)(Hdpa)(H 2O) 4]·2H 2O} ( 6, sip = 5-sulfoisophthalate) are coordination complexes. Antiferromagnetic superexchange is observed in 1 and 4, with concomitant zero-field splitting. Thermal decomposition behavior of the higher dimensionality complexes is also discussed.