Jacob W. Uebler

Donor disposition and aliphatic conformation effects on structure in luminescent zinc dicarboxylate coordination polymers with isomeric dipyridylamide coligands

Hydrothermal reaction of zinc nitrate, a four-carbon chain dicarboxylic acid, and one of three isomeric dipyridylamide coligands has afforded a family of six new coordination polymers, which have been structurally characterized by single-crystal X-ray diffraction. The binding modes and conformations of the dicarboxylate ligands and the nitrogen donor disposition within the dipyridylamide coligands provide crucial structure-directing roles in this system. {[Zn(fum)(3-pina)]·1.5H2O}n (1, fum = fumarate, 3-pina = 3-pyridylisonicotinamide) has a 4-fold interpenetrated 43628 sra topology. [Zn(fum)(4-pna)]n (2, 4-pna = 4-pyridylnicotinamide) possesses a 4-fold interpenetrated 66dia topology, while [Zn(fum)(4-pina)]n (3, 4-pina = 4-pyridylisonicotinamide) has a 2-fold interpenetrated 41263pcu topology with dimeric cluster nodes. [Zn3(mal)2(OH)2(4-pina)2]n (4, mal = maleate) has neutral [Zn3(mal)2(OH)2]n ribbons linked into a (3,6) triangular layer. [Zn(suc)(4-pina)]n (5, suc = succinate) displays an uncommon 6-connected self-penetrated 446108 mab topology, while instead [Zn(suc)(4-pna)]n (6) has a simple corrugated (4,4) grid structure. Thermal and luminescent properties of these new materials have also been investigated.

Cadmium adipate coordination polymers prepared with isomeric pyridylamide precursors: pH-dependent in situ reaction chemistry and divergent dimensionalities

Hydrothermal reaction of cadmium nitrate, adipic acid (H2adp), and a pyridylnicotinamide precursor has afforded four new crystalline coordination polymer solids. The 1-D ribbon coordination polymer {[Cd2(adp)(nic)2(H2O)3(3-ampyr)]·5H2O}n (1, nic = nicotinate, 3-ampyr = 3-aminopyridine) resulted from in situ hydrolysis of the 3-pyridylnicotinamide (3-pna) precursor under basic conditions. Incipient voids within the crystal lattice of 1 contain T5(2)5(2)A(0) water molecule chains. Eschewing addition of extra base to the reaction mixture resulted in the isolation of the 3-D coordination polymer {[Cd2(adp)(nic)2(3-pna)2]·6H2O}n (2), in which some of the 3-pna starting material remains intact. The underlying 5-connected 4664bnn 3-D network of 2 arises from the linkage of similar ribbon motifs to those observed in 1. Use of either 3-pyridylisonicotinamide (3-pina) or 4-pyridylnicotinamide (4-pna) precursors avoids any amide hydrolysis, affording the decorated (4,4) grid 2-D coordination polymer {[Cd(adp)(3-pina)]·H2O}n (3) or the 1-D chain compound {[Cd(adp)(4-pna)2(H2O)2]·2H2O}n (4), respectively. Luminescent and thermal properties of these materials are also presented.

Metal dependent dimensionality in sulfate coordination polymers containing 3-pyridylisonicotinamide

Hydrothermal synthesis has afforded divalent metal sulfate coordination polymers containing 3-pyridylisonicotinamide (3-pina), whose dimensionalities depend crucially on the specific metal used and sulfate binding mode. {[Co(H2O)4(3-pina)]SO4·5H2O}n (1) shows a 1D chain structure with unligated sulfate ions. {[Cu(SO4)(3-pina)(H2O)]·H2O}n (2) possesses a (4,4) grid structure formed by the linkage of copper sulfate 1D chains through 3-pina tethers. [Cd(SO4)(3-pina)(H2O)]n (3) has exotridentate sulfate ions and a 2-fold interpenetrated 3,5-connected binodal 3D network with a very uncommon (426)(426583) binodal topology. The topology of 3 differs greatly from those seen in analogous 4,4′-bpy phases, including a previously unidentified self-penetrated network. The sulfate linkages in 2 promote weak ferromagnetic coupling between copper ions along 1D [Cu(SO4)]n zig-zag chains, with g = 2.10(3) and J = 0.66(11) cm−1. The cadmium derivative 3 undergoes luminescence upon exposure to ultraviolet light (λmax ∼430 nm).

Diaqua­bis­[N-(pyridin-4-yl)isonicotin­amide-κN]bis­(thio­cyanato-κN)cobalt(II)

In the title compound, [Co(NCS)2(C11H9N3O)2(H2O)2], the octahedrally coordinated CoII ion lies on a crystallographic inversion center and is bound by two isothiocyanate ligands, two aqua ligands and two N-(pyridin-4-yl)isonicotinamide (4-pina) ligands. The dihedral angle between the aromatic rings in the 4-pina ligand is 8.98 (11)°. In the crystal, the individual molecular units are aggregated in three dimensions by O—H⋯N, O—H⋯S and N—H⋯S hydrogen-bonding pathways.

catena-Poly[[(triaqua-cadmium)-μ-1,4-phenyl-enediacetato-κO,O':O'',O'''] dihydrate].

In the title compound, {[Cd(C10H8O4)(H2O)3]·2H2O}n, pentagonal–bipyramidally coordinated CdII ions on a twofold rotation axis are linked by tethering 1,4-phenylenediacetate (1,4-phda) ligands into [Cd(1,4-phda)(H2O)3]n coordination polymer chains. The chain motifs are oriented parallel to the c-axis direction. Individual chains are connected into a supramolecular network via O—H⋯O hydrogen bonding involving the aqua ligands.