[Cu(X-salicylato)2(N,N-diethylnicotinamide)2(H2O)2] complexes: conformational polymorphism and its consequence in supramolecular hydrogen-bonding networks formation

Abstract

Novel copper(II) X-salicylate complexes with N,N-diethylnicotinamide (dena) of the formula [Cu(R-COO) 2 (dena) 2 (H 2 O) 2 ] (RCOO = 3-methylsalicylate anion (3-Mesal, 1), 4-methylsalicylate anion (4-Mesal, 2), 5-methylsalicylate anion (5-Mesal, 3), 5-methoxysalicylate anion (5-MeOsal, 4) or 4-methoxysalicylate anion (4-MeOsal, 5)), and complex (6)) have been prepared in the crystalline forms and characterized by spectroscopic methods (IR, Vis-UV, EPR). All the compounds according to their composition (1-5) seem to possess octahedral copper(II) stereochemistry. The complex 1 has been prepared in two different forms. X-ray analyses of the complexes 1, 4, and 5 were carried out and they featured a tetragonal-bipyramidal geometry around the copper atoms. The tetragonal planes are created by X-salicylate anions bonded to the copper(II) atoms via unidentate carboxylate oxygen atoms and the pyridine ring nitrogen atoms of the neutral ligand N,N-diethylnicotinamide, while in axial positions are water molecules. The two forms of complex 1 present conformation polymorphs and supramolecular isomers.

Effect of the Pyridine Substituent on the Role of the Phenol Functional Group in [Cu(pOHBz)2(dPy)2] Complexes (pOHBz: p‐Hydroxybenzoate, dPy= 4‐Phenylpyridine, 4‐Benzylpyridine, 3‐Phenylpyridine).

“…It is remarkable that this phenol disposition resembles the found in compound 2 , although in such structure the oxygen of the phenol is at a greater distance from the copper cation, 3.171 Å, and thus is considered not bonded. Other bond lengths and angles are in good agreement with literature values for other copper complexes with similar coordination geometry ,,…”

Interplay of thermochemistry and Structural Chemistry, the journal (volume 21, 2010) and the discipline

“…In the experimental study by Repická et al [271] synthesis of five new monomeric 3-, 4-, and 5-methylsalicylatocopper(II), and 4-and 5-methoxysalicylatocopper(II) complexes with N,N-diethylnicotinamide as monodentate terminal ligand is reported. All these compounds seem to possess octahedral copper(II) stereochemistry.…”

Bis(3-methylsalicylato)bis(picolinamide)copper(II) complex — preparation, spectral properties and supposed structure

“…Different intermolecular interactions can lead to the formation of various supramolecular architectures which leads to variable structure modifi cations. It is well known that hydrogen bonds formation plays a signifi cant role, therefore, these coordination compounds are interesting for solid state chemistry and bioinorganic chemistry (Moncol, 2008;Repická, 2010). Currently, nia derivatives like picolinamide (pnia) or isonicotinamide (inia) provide several structure motifs especially in this fi eld of various carboxylatocopper(II) complexes.…”