Cd(II) coordination polymers based on expanded N, N′-heteroaromatic donor ligands. (5th September 2017)

• Record Type: Journal Article
• Authors: Zahedi, Mansoureh; Shaabani, Behrouz; Englert, Ulli; Rad-yousefnia, Negar; Blake, Graeme R.; Kazak, Canan
• Is Part Of: Polyhedron. Volume 133(2017)
• Page Start: 110
• Page End: 118
• Publication Date: 2017-09-05
• Subjects: Coordination polymers -- Expanded N, N′ donor ligands -- Cadmium(II) complexes -- Fluorescence -- Thermal analysis; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.05.023
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Four Cd(II) coordination polymers were generated from two isomeric expanded aromatic N, N′ donor linkers and acetate or iodide as co-ligands. X-ray diffraction revealed the decisive effect of the co-ligands on the coordination sphere and the topology of the products. The solids thus generated are thermally stable and show fluorescence at room temperature. Abstract: The isomeric N donor linkers bis(pyridin-4-ylmethylene)naphthalene-1, 5-diamine (L1 ) and bis(pyridin-3-ylmethylene)naphthalene-1, 5-diamine (L2 ) have been used with acetate and iodide as co-ligands to generate four new cadmium(II) coordination polymers. [CdL1 (OAc)2 ] n (1 ), [CdL1 (I)2 ] n (2 ), [CdL2 (OAc)2 ] n (3 ) and [CdL2 (I)2 ] n (4 ) were characterized by elemental analysis, X-ray powder diffraction, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. In line with the concept of crystal engineering, their structures share common motifs: the heteroaromatic linkers generate chains, subtending Cd⋯Cd distances consistent with their N donor arrangement. The co-ligands control the coordination number of the Cd(II) cations and interchain connectivity: The acetate moieties either adopt bridging and chelating or exclusively bridging modes and crosslink essentially linear chains based on octahedral metal centers; in the former case, the ladder-like one-dimensional ribbon1 is generated, whereas the latter connectivity results in the two-dimensional layer structure3 . In contrast, iodide acts as terminal ligand towards tetrahedral Cd(II), and hence2 and4 are single-stranded 1D zig-zag polymers. In comparison to the uncoordinated heteroaromaticL1 andL2, the Cd coordination polymers show slightly red-shifted luminescence spectra of significantly higher intensity due to the more rigid arrangement of the π systems.