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A series of Co(II), Ni(II) and Cu(II) coordination polymers and dinuclear metallocycles containing 4-aminopyridine (4-ampy) and benzenedicarboxylate ligands, {[M(4-ampy)₂(1,4-BDC)]·H₂O·CH₃CH₂OH}_n (M = Ni, <b>1a</b>; Co, <b>1b</b>, 1,4-H₂BDC = benzene-1,4-dicarboxylic acid), {[Ni₂(4-ampy)₄(1,3-BDC)₂]·H₂O·CH₃CH₂OH}_n (1,3-H₂BDC = benzene-1,3-dicarboxylic acid), <b>2</b>, [M₂(4-ampy)₄(1,2-BDC)₂] (M = Ni, <b>3a</b>; Co, <b>3b</b>, 1,2-H₂BDC = benzene-1,2-dicarboxylic acid), [Co(4-ampy)₂(1,3-BDC)]_n, <b>4</b>, {[Cu(4-ampy)₂(1,4-BDC)] CH₃CH₂OH}_n, <b>5a</b>, and {[Cu(4-ampy)₂(1,4-BDC)]·H₂O}_n, <b>5b</b>·H₂O, are reported, which were hydrothermally prepared and structurally characterized by using single crystal X-ray diffraction. Complexes <b>1a</b> and <b>1b</b> are isomorphous 1D zigzag chains, while <b>2</b> displays a concave–convex chain and <b>3a</b> and <b>3b</b> are dinuclear metallocycles that differ in the boding modes of the 1,2-BDC²⁻ ligands, forming a 3D and a 2D supramolecular structures with the <b>pcu</b> and <b>sql</b> topologies, respectively. Complex <b>4</b> exhibit a 1D helical chain and complexes <b>5a</b> and <b>5b</b>·H₂O are 1D linear and zigzag chains, in which the Cu₂-1,4-BDC²⁻ units adopt the <i>cis</i> and <i>trans</i> configurations, respectively. A novel irreversible structural transformation due to <i>cis</i>→<i>trans</i> isomerization of the Cu₂-1,4-BDC²⁻ units was observed in <b>5b</b>⋅H₂O and <b>5a</b> upon water adsorption of the desolvated product of <b>5b</b>·H₂O.