Two Coordination Polymers Created via In Situ Ligand Synthesis Involving C−N and C−C Bond Formation

We report the synthesis and crystal structures of two transition metal-based coordination polymers comprising ligand molecules not included in the original reaction mixtures but instead formed in situ during hydrothermal treatment. Zinc <i>meso</i>-iminodisuccinate hydrate (<b>I</b>), Zn<sub>2</sub>(C<sub>8</sub>H<sub>7</sub>NO<sub>8</sub>)·0.57H<sub>2</sub>O, formed from zinc acetate and l-aspartic acid, and tetraaquanickel(II) 5,10-dioxo-5,10-dihydro-4,9-dioxa-pyrene-2,7-dicarboxylate (<b>II</b>), Ni(H<sub>2</sub>O)<sub>4</sub>(C<sub>16</sub>H<sub>4</sub>O<sub>8</sub>), formed from nickel acetate and 5-hydroxyisophthalic acid. We show that the formation of <b>I</b> takes place via a fumaric acid intermediate, while the formation of <b>II</b> requires the formation of a new C−C bond. The structure of <b>I</b> consists of weakly interacting sheets, while the structure of <b>II</b> consists of strongly hydrogen-bonded chains. Crystal data:  for <b>I</b>,<i> P</i>2<sub>1</sub>/<i>n</i> (14), <i>a</i> = 10.073 Å, <i>b</i> = 9.894 Å, <i>c</i> = 12.053 Å, β = 105.605°, <i>V</i> = 1156.87(13) Å<sup>3</sup>, <i>Z</i> = 4; for <b>II</b>, <i>P</i>1̄ (2), <i>a</i> = 5.011 Å, <i>b</i> = 6.526 Å, <i>c</i> = 12.305 Å, α = 76.868°, β = 84.988°, γ = 87.619°, <i>V</i> = 390.3(4) Å<sup>3</sup>, <i>Z</i> = 1.