A series of one-dimensional zinc(II) coordination polymers with three-dimensional supramolecular networks: Synthesis, structural investigation and NBO analysis
Creators: name: Zahedi, Mansoureh
name: Shaabani, Behrouz
name: Radyousefnia, Negar
name: Englert, Ulli
name: Blake, Graeme R.
name: Aygün, Muhittin
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Biophysics
subject: Biochemistry
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: FOS: Physical sciences
subject: Cell Biology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: FOS: Chemical sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: FOS: Biological sciences
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: FOS: Health sciences
subject: Computational Biology

description: <i>N,N′</i>-Bis(pyridin-4-ylmethylene)naphthalene-1,5-diamine (L) acts as a bipyridine analogue linker ligand towards {Zn<sub>7</sub>(μ<sub>4</sub>-O)<sub>2</sub>(OAc)<sub>10</sub>}, {Zn<sub>2</sub>(NCS)<sub>2</sub>(OAc)<sub>2</sub>} and {Zn(N<sub>3</sub>)<sub>2</sub>} nodes and allows construction of three new one-dimensional coordination polymers, the linear chain [Zn<sub>7</sub>(μ<sub>4</sub>-O)<sub>2</sub>(OAc)<sub>10</sub>(L)]<sub>n</sub> (<b>1</b>), [Zn(NCS)(OAc)(L)]<sub>n</sub> (<b>2</b>) in ladder-type geometry and the zigzag chain [Zn(N<sub>3</sub>)<sub>2</sub>(L)]<sub>n</sub> (<b>3</b>). Structural characterization reveals that in <b>1</b> acetate anionic ligands connect seven Zn(II) ions through the bridging coordination modes μ<sub>3</sub>-η<sup>1</sup>,η<sup>2</sup> and μ<sub>2</sub>-η<sup>1</sup>,η<sup>1</sup>. The resulting heptanuclear node is located on an inversion center and therefore consists of four crystallographically distinct cations; their coordination spheres correspond to distorted octahedra or tetrahedra. The Zn(II) ions in polymer <b>2</b> exhibit distorted trigonal bipyramidal {ZnN<sub>3</sub>O<sub>2</sub>} coordination; μ<sub>2</sub>-η<sup>1</sup>,η<sup>1</sup> coordinated acetate and terminal thiocyanate ligands lead to inversion-symmetric [Zn<sub>2</sub>(NCS)<sub>2</sub>(OAc)<sub>2</sub>] secondary building units (SBU), which are further linked by the N,N′-bipyridine analogue L. Terminal coordination of two anionic azide ligands and the bridging bipyridine L result in coordination polymer <b>3</b>, in which the cations adopt distorted tetrahedral {ZnN<sub>4</sub>} coordination. In all crystalline solids <b>1</b>-<b>3</b>, adjacent 1-D chains interact through π–π stacking and non-classical (C−H···O, C−H···π) hydrogen bonds, leading to 3-D supramolecular architectures. Differences in their 3D arrangement are due to variations in the anionic co-ligands, subtle conformational differences in the semi-rigid linker and the variable coordination sphere about the zinc cations. Thermogravimetric investigations indicate differences in both thermal stability and decomposition mode. Natural bond orbital (NBO) analysis provides a convenient basis for investigating the intramolecular bonding interactions and delocalization effects in these molecular systems. Finally, solids <b>1</b>-<b>3</b> exhibit intense luminescence at room temperature.