Luminescent coordination polymers of 2,2′-bipyrimidine and mercury(II) salts: A structural and computational study

Abstract

We report the synthesis and structural, thermal and vibrational characterization of five complexes of the 2,2'bipyrimidine (bipym) with HgX 2 , X=Cl, Br, I, CN, SCN, with the aim to investigate the factors that could influence the supramolecular chemistry of mercury(II). The combination of the 2,2'-bipym ligand, a bidentate molecule, and bridging anions together with a d 10 metal like mercury(II) has given different polymeric structures with 1D and 3D dimensionality. A computational modelling, compared to statistical analysis of reported structures, has allowed to rationalize the differing contribution of bipym and halide and pseudohalide ligands to supramolecular architecture. Solid state photoluminescent properties have been investigated and an interpretation based on computational models has been proposed.

HgBrI: a possible tecton for NLO molecular materials?

“…It has been demonstrated that upon moving from the chloride to the iodide, the bridging behaviour is reduced and the bridging interactions are weaker. 28 In the case of bpy complexes, the chloride forms a true 1D-coordination polymer, 18 while the bromide and iodide form dimers that interact through spodium bonding, 50 giving dimeric molecular entities 19 and very weakly interacting dimers, 20 respectively. The packing of 2 is an intermediate between that of bromide and iodide: very long spodium bonding interactions connect the molecules of the dimers, at the edge of the VdW sum ( d (Br/I⋯Hg) = 3.404(8) Å and 3.377(8) Å, respectively).…”

Modulation of the Structure and Photoluminescence of Bismuth(III) Chloride Hybrids by Altering the Ionic-Liquid Cations

“…For example, in [(CuI) 2 (bpym)], 13a the rhombus-shaped Cu 2 I 2 motifs could be bridged by the bpym ligands leading to a chain, in which the cable of two bridged iodine is perpendicular to bpym plane (Figure S4a,b). In [Hg 2 I 4 (bpym)], 16 the dimeric Hg 2 I 4 fragments with two different orientations are interconnected by bpym ligands to form an infinite chain (Figure S4c). The dihedral angle between dimeric metal halide plane (Hg 2 I 2 ) and bpym plane is 53.11°, which is smaller than that of 1 (70.05°) and 2 (74.80°) (Figure S4d).…”

“…This is similar to [Hg 2 I 4 (bpym)] whose absorption is calculated to be the charge-transfer from inorganic moiety I to bpym. 16 Therefore, the band edge absorption around 375 nm should arise from the inorganic moiety (i.e., Bi and Cl) to organic ligand (bpym) chargetransfer (IOCT), in which the main contribution is from Cl to bpym, namely, interligand LLCT. The bandgaps of 1 and 2 are calculated to be indirect 2.501 and 2.481 eV, respectively.…”

“…For instance, bpym-coordinated Hg 2+ halides can emit PL at ca. 460 and 560 nm from bpym, 16 and lanthanide (e.g., Eu 3+ and Tb 3+ )−bpym complexes achieve fluorescence originated from ligand-to-metal charge-transfer (LMCT). 19a Specially, the four N sites of bpym can chelate two different types of metal ions (such as transition metals ion and lanthanide), resulting in heterodinuclear compounds with near-infrared luminescence of lanthanides ions (Nd 3+ , Er 3+ , and Yb 3+ ions).…”

The use of the phosphor of phosphogypsum as a filler for fluorescent polymers

“…Их применяют для создания светодиодов и светящихся дисплеев [1,2], для технического анализа и контроля качества [3,4]. Ведутся работы по фундаментальным исследованиям люминесцентных полимерных композиций [5][6][7].…”