[2+2] or [4+4] metallamacrocycle: Synthesis and crystal structures of Hg(II) complexes derived from two flexible bis(pyridylurea) ligands

Crystal structure of N′,N′′′-((1E,1′E)-(propane-2,2-diylbis(1H-pyrrole-5,2diyl))bis(methaneylylidene))di(nicotinohydrazide) pentahydrate, C25H24N8O2·5H2O

C25H34N8O7, triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 7.507(2) Å, b = 8.0276(18) Å, c = 23.653(6) Å, α = 93.062(8)°, β = 97.015(9)°, γ = 99.478(8)°, V = 1391.4(6) Å3, Z = 2, R gt (F) = 0.0473, wR ref(F 2) = 0.1477, T = 273 K.

Intrinsic structural features of coordination polymers make an impact on dye selectivity

Differences in hydrogen-bonded assembly help in recognition of dyes.

Self-Assembly by Tridentate or Bidentate Ligand: Synthesis and Vapor Adsorption Properties of Cu(II), Zn(II), Hg(II) and Cd(II) Complexes Derived from a Bis(pyridylhydrazone) Compound

Four complexes, [Cu₄L₂(OCH₃)₂(CH₃OH)₂]·2H₂O (1), [Zn₂L₂Cl₄]·2H₂O·2CH₃OH (2), [Hg₂L₂Br₄]·4CH₃OH (3), and {[CdL₂Cl₂]·4H₂O·4CH₃OH}_n (4), have been synthesized and characterized from a bis(pyridylhydrazone) ligand (L) with copper(II), zinc(II), mercury(II) or cadmium(II), respectively. Complex 1 exists as a centrosymmetric tetranuclear dimer with L as deprotonated tridentate ligand. Complexes 2 and 3 exist as centrosymmetric metallamacrocycles with L as bidentate ligand. Complex 4 exists as a 1D looped-chain coordination polymer. The thermal stabilities and vapor adsorption properties of the four complexes were investigated as well.