Three zinc(II) and cadmium(II) complexes containing 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole and polynitrile ligands: synthesis, molecular and supramolecular structures, and photoluminescence properties

Abstract

Three photoluminescent complexes containing either Zn or Cd have been synthesized and their structures determined. Bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κN,N]bis(dicyanamido-κN)zinc(II), [Zn(CHN)(CN)], (I), bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κN,N]bis(dicyanamido-κN)cadmium(II), [Cd(CHN)(CN)], (II), and bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κN,N]bis(tricyanomethanido-κN)cadmium(II), [Cd(CHN)(CN)], (III), all crystallize in the space group P-1, with the metal centres lying on centres of inversion, but neither analogues (I) and (II) nor Cd complexes (II) and (III) are isomorphous. A combination of N-H...N and C-H...N hydrogen bonds and π-π stacking interactions generates three-dimensional framework structures in (I) and (II), and a sheet structure in (III). The photoluminescence spectra of (I)-(III) indicate that the energies of the π-π* transitions in the coordinated triazole ligand are modified by minor changes of the ligand geometry associated with coordination to the metal centres.

Intermolecular interactions in antipyrine-like derivatives 2-halo-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)benzamides: X-ray structure, Hirshfeld surface analysis and DFT calculations

“…Crystal engineering and supramolecular interactions, including non-covalent interactions, have attracted considerable attention in the design of new receptors and supramolecular materials [12][13][14][15]. Non-covalent interactions such as hydrogen bonding, halogen bonding, C-H•••π interactions, π-π stacking, dispersive interactions, σ-hole interactions, π-hole interactions, and other weak contacts play crucial roles in various fields of medicinal chemistry and materials science [16][17][18][19][20].…”

Solvothermal synthesis and crystal structures of two new cadmium coordination polymers containing polynitrile ligands

“…Structures have been reported for (2,2 0 -bipy) 2 Cd(dca) 2 (Mal et al, 2012) and for cadmium complexes of both dac and tcm containing 4-amino-3,5-bis(pyridine-2-yl)-1,2,4-triazole as the neutral co-ligand (Setifi et al, 2017), but these compounds all comprise monomeric complexes in which the octahedral units are linked only by hydrogen bonds andstacking interactions. Although the two triazole complexes both crystallize in space group P1, they are not isomorphous: this behaviour mirrors that of compounds (I) and (II) reported here.…”

Six tris(bipyridyl)iron(II) complexes with 2-substituted 1,1,3,3-tetracyanopropenide, perchlorate and tetrafluoridoborate anions; order versus disorder, hydrogen bonding and C—N...π interactions

“…The use of polynitrile anions as ligands, either alone or in combination with neutral co-ligands, is a very versatile and effective strategy for developing molecular architectures with ISSN 2056-9890 different topologies and dimensionalities, as a result of their ability to coordinate and bridge metal ions in many different ways (Benmansour et al, 2008(Benmansour et al, , 2010(Benmansour et al, , 2012Atmani et al, 2008;Gaamoune et al, 2010;Setifi, Setifi, El Ammari et al, 2014;Addala et al, 2015). The presence of other potential donor groups such as -OH, -SH or -NH 2 , together with their rigidity and their electronic delocalization, can lead to the synthesis of new magnetic and luminescent coordination polymers with transition-metal ions (Benmansour et al, 2010;Yuste et al, 2009;Setifi et al, 2009;Setifi, Zambon et al, 2017;Kayukov et al, 2017;Lehchili et al, 2017). Furthermore, these ligands have shown both coordinating and bridging capabilities in novel discrete and polymeric bi-stable materials (Setifi, Milin et al, 2014;Milin et al, 2016;Pittala et al, 2017).…”