Synthesis, crystal structure and study of the crystal packing in the complex bis(4‐aminopyridine‐κN1)dichloridocobalt(II)

• Published in: Acta crystallographica. Section C, Crystal structure communications Crystal structure communications, 2017-05, Vol.73 (5), p.399-406
• Main Authors: Sanchez Montilva, Olga Carolina, Movilla, Federico, Rodriguez, Maricel Gabriela, Di Salvo, Florencia
• Format: Article
• Language: English
• Subjects: 4‐aminopyridine; Bonding; Cobalt; cobalt complex; Coordination compounds; Crystal structure; Crystals; Diffraction; Ethanol; fingerprint plots; Hirshfeld analysis; Hydrogen bonds; Pyridines; pyridine–pyridine dimer; Single crystals; Surface analysis (chemical); X-ray diffraction; π–π stacking
• ISSN: 2053-2296; 0108-2701; 2053-2296; 1600-5759
• DOI: 10.1107/S2053229617004880

Despite the large number of reported crystalline structures of coordination complexes bearing pyridines as ligands, the relevance of π–π interactions among these hereroaromatic systems in the stabilization of their supramolecular structures and properties is not very well documented in the recent literature. The title compound, [CoCl2(C5H6N2)2], was obtained as bright‐blue crystals suitable for single‐crystal X‐ray diffraction analysis from the reaction of 4‐aminopyridine with cobalt(II) chloride in ethanol. The new complex was fully characterized by a variety of spectroscopic techniques and single‐crystal X‐ray diffraction. The crystal structure showed a tetrahedral complex stabilized mainly by bidimensional motifs constructed by π–π interactions with large horizontal displacements between the 4‐aminopyridine units, and N—H…Cl hydrogen bonds. Other short contacts, such as C—H…Cl interactions, complete the three‐dimensional arrangement. The supramolecular investigation was extended by statistical studies using the Cambridge Structural Database and a Hirshfeld surface analysis. A new cobalt(II) pyridine‐based coordination compound showing π–π interactions with large horizontal displacements between the 4‐aminopyridine ligands and N—H…Cl and C—H…Cl hydrogen bonds is reported. The molecular and supramolecular structures have been studied in detail and compared with those of similar complexes found in a search of the Cambridge Structural Database. The supramolecular structure was also investigated by Hirshfeld surface analysis.