Synthesis, Crystal Structures, and Photoluminescence of a Series of Coordination Polymers with Two Homologous Functional Flexible Ligands

Abstract

Two functional, flexible ligands, namely 3,6‐dipyrazolyl‐9‐ethylcarbazole (L1) and 3,6‐diimidazolyl‐9‐ethylcarbazole (L2) have been synthesized and characterized and their coordination to various AgI, CdII, and CoII salts investigated. Six new complexes, 1–6, have been obtained and fully characterized by IR spectroscopy, elemental analysis, and single‐crystal X‐ray diffraction. The 2D double helix framework of the complex [CdL1I2]n (1) is formed by C–H···I hydrogen bonds, whereas the same 2D double helix framework of compound [{AgL1SO3PhCH3}2(CH3OH)(H2O)]n (2) is formed by S–O···H and C–H···O hydrogen bonds and weak π–π interactions. The coordination modes of CdII and CoII in [CdL22(NCS)2]n (3), [CoL22(NCS)2(CHCl3)2]n (4), [CdL22(NO3)2(CH3OH)2]n (5), and [CoL22(NO3)2(CH3OH)2]n (6) are the same, but in the packing diagram interlayers form a 3D network through C–H···S interactions and π–π interactions in 3, interlayers form a 3D network through S···S interactions and π–π interactions in 4, novel 3D structures are formed by interchain O···H–C hydrogen bonding and interlayer O···H–C hydrogen‐bonding and π–π interactions in 5 and 6. The structural differences between these complexes show the influence of the orientation of the coordinating group of the ligand. These results also show that the metal ion, anion, and nonbonding and π–π interactions are significant factors in controlling the structural topology of these metal‐organic supramolecular architectures. In addition, the luminescence properties of L1, 1, L2, and 3 are investigated in the solid state at room temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Cation-induced assembly of Zn(II), Cd(II) and Hg(II) coordination complexes and DFT calculations to evaluate weak interactions between the helical chains

“…Taking the van der Waals radii of H and I to be 1.20 Å and 2.15 Å, respectively, any H···I contact less than 3.35 Å and CH···I angle < 130° may therefore potentially be considered significant [27]. So parallel-helical chains of complex 1 and 3 contain CH···I weak interactions, however, there are no CH···I weak interactions in that of complex 2.…”

Synthesis, crystal structures and electrochemical properties of two new metal-centered ferrocene complexes

“…Another is defined by C(imidazole) -H···S(SCN) hydrogen bond, with the distance of H···S is 2.945(2) Å, and bond angle ∠C-H···S is 150.6(1)°. Taking the van der Waals radii of H and S to be 1.20 and 2.05 Å, respectively, any H···S contact of less than 3.25 Å and C-H···S angle greater than 130° can therefore be considered as being significant [37] . The C-H···S hydrogen bond is very important in supramolecular self-assembly [38,39] .…”

Synthesis, crystal structure and photoluminescence of a new Cd(II) coordination polymer with unusual geometry

“…Most carbazole compounds emit at wavelengths N400 nm in solid state [31][32][33] due to the aromatic π-π stacking. Complex [CdL 2 (NO 3 ) 2 ] n presents a broad strong emission band with a maximum at 404 nm, which is largely characteristic of an intraligand fluorescent emission [34]. Accordingly, the complex [CdL 2 (NO 3 ) 2 ] n may be a potential candidate in blue-light emitting materials, for it is thermally stable and insoluble in common polar and nonpolar solvents.…”