Divergent topologies in luminescent zinc and cadmium substituted isophthalate coordination polymers constructed from long-spanning dipyridylamide ligand precursors

Hydrothermal reaction of zinc or cadmium nitrate, a 5-position substituted isophthalic acid, and the long-spanning dipyridylamide ligand N,N'-(hexane-1,6-diyl) dinicotinamide (hdn) resulted in coordination polymers whose dimensionalities depend on the nature of the ring substituent and the metal coordination environment. The six new phases were characterized by single crystal X-ray diffraction. {[Zn-2(hip)(2)(H2O)(2)(hdn)]center dot 2H(2)O}(n) (1, hip = 5-hydroxyisophthalate) shows a 1D ladder topology with [Zn (hip)(H2O)](n) uprights spanned by disordered hdn rungs. {[Zn-2(nip)(2)(hdn)(2)]center dot 2H(2)O}(n) (2, nip = 5-nitroisophthalate) displays a 1D ribbon motif with [Zn(nip)](n) chains pillared by looped pairs of hdn ligands. [Zn-3(tbip)(2)(nic)(2)](n) (3, tbip = 5-tert-butylisophthalate, nic = nicotinate) shows trimeric [Zn-3(OCO)(2)] clusters connected into a 3D 8-connected 4(24)6(4) bcu net by tbip and in situ generated nic ligands. {[Cd-2(ip)(2)(H2O)(4)(hdn)]center dot 2H(2)O}(n) (4, ip = isophthalate) and {[Cd-2(tbip)(2)(H2O)(4)(hdn)]center dot H2O}(n) (5) both show a ladder topology similar to that in 1. {[Cd(mip)(hdn)]center dot H2O}(n) (6, mip = 5-methylisophthalate) manifests a 2D (4,4) grid topology based on linked dimeric [Cd-2(OCO)(2)] units. Luminescent properties were probed; compounds 4 and 6 showed good ability to detect nitrobenzene in ethanol suspension. (C) 2017 Elsevier B.V. All rights reserved.