New complexes constructed from in situ nitration of (1H-tetrazol-5-yl)phenol: synthesis, structures and properties

Abstract

Nine new complexes, {[Zn₃(L¹)₂(OH)₂]·H₂O}_n (1), [Ag₂(L¹)]_n (2), {[Co(HL¹)₂(H₂O)₄]·2H₂O} (3), [Cu₃(L¹)₂(OH)₂(H₂O)]_n (4), {[Cu₇(HL¹)₂(L¹)₆(H₂O)₆]·11.1H₂O}_n (5), {[Cu(L¹)(H₂O)₃]·8H₂O}_n (6), [Ag₂(L²)]_n (7), [Ag₈(L³)₄(H₂O)]_n (8) and [Cu(L³)(H₂O)₂]_n (9) [H₂L¹ = 2,6-dinitro-4-(1H-tetrazol-5-yl)phenol, H₂L² = 2,4,6-trinitro-3-(1H-tetrazol-5-yl)phenol, H₂L³ = 2,4-dinitro-6-(1H-tetrazol-5-yl)phenol], have been solvothermally synthesized via in situ nitration from 4-(1H-tetrazol-5-yl)phenol, 3-(1H-tetrazol-5-yl)phenol and 2-(1H-tetrazol-5-yl)phenol precursors as well as nitrate salts as nitration reagents and structurally characterized by single-crystal X-ray diffraction, infrared spectroscopy (IR), elemental analysis, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). The structures of the complexes vary from 3D frameworks for 1, 4 and 7, 2D networks for 2, 5 and 8, 1D chains for 6 and 9, to a discrete 0D structure for 3, showing 2D supramolecular structures by interlayer π–π stacking. Topological classification of 2D and 3D architectures was performed, disclosing a variety of topological symbols: (4²·6)₂(4⁴·6²·8⁸·10) for 1, (4³)₂(4⁶·6⁶·8³) for 2, (4⁶)₂(4¹²·61²·8⁴) for 4, (6³) for 5 and (4⁵·6)(4⁷·6³)(4¹⁸·6¹⁶·8²) for 7. The contrast of 1–9 reveals that ligands and metal salts have important influences on adjusting the crystal structures; notably, the coordination modes of the ligands can also tune the structures of 4–6 which possess the same ligands and nitration agents. The solid-state UV-vis spectra and band gap energy of the nine complexes were investigated. In addition, the luminescence properties (for complexes 1–3, 7 and 8) and magnetic properties (for complexes 3–6 and 9) were also discussed.