Supramolecular and theoretical perspectives of 2,2′:6′,2′′-terpyridine based Ni(ii) and Cu(ii) complexes: on the importance of C–H⋯Cl and π⋯π interactions

Abstract

In this manuscript we report the synthesis and X-ray characterization of two new Ni(ii) and Cu(ii) complexes using 2,2′:6′,2′′-terpyridine as a ligand and chloride as a coligand.

Syntheses, crystal structures and supramolecular assemblies of two Cu(ii) complexes based on a new heterocyclic ligand: insights into C–H⋯Cl and π⋯π interactions

“…17 Among non-classical hydrogen bonding (C-H⋯N/O/X) interactions, the C-H⋯Cl interaction attracts interest in the broad field of materials chemistry, 18 C-H activation, 19 ion transport, 20 and anion recognition, 21 as well as in constricting molecular architectures. 22,23 As anticipated, the C-H⋯Cl distance should be less than the sum of the van der Waals radii (2.95 Å) of the hydrogen atom and the neutral chlorine atom for a superior C-H⋯Cl interaction. 24 In our present work such distances are in the range of 2.49 to 2.83 Å.…”

“…The axial chloride (Cl2) is positioned somewhere at a longer distance [Cu1-Cl2 = 2.3629 (10) Å] than the equatorial one [Cu1-Cl1 = 2.2495(9) Å] likely due to the less 's' character of the orbital engaged in the coordination bond, which makes the axially coordinated chloride anion more electronegative (stronger hydrogen bond acceptor). 23 The Cu(II) ion is shifted by a distance of 0.437…”

“…The existence of C-H⋯Cl interactions triggered by chargeassisted terminal M-Cl bonds has been well established in recent times. 23,63 The formation of a 2-D supramolecular architecture (Fig. 4) is ensured by various C-H⋯Cl interactions (Table S4, ESI †).…”

Two dinuclear copper (II) and nickel (II) complexes based on 4‐(diethylamino)salicylaldehyde: X‐ray structures, spectroscopic, electrochemical, antibacterial, Hirshfeld surfaces analyses, and time‐dependent density functional theory calculations

“…[ 37 ] The dihedral angles of [Cu 2 ( L 2 ) 2 (NO 3 ) 2 ] between N1O3 basal plane and N2–O2–N1 and O3–N2–N1 planes were 63.697° and 77.389°, while dihedral angles of [Ni 2 ( L 2 ) 2 (CH 3 COO) 2 ] were 60.121° and 57.825°. [ 38,39 ]…”

“…[37] The dihedral angles of [Cu 2 (L 2 ) 2 (NO 3 ) 2 ] between N1O3 basal plane and N2-O2-N1 and O3-N2-N1 planes were 63.697 and 77.389 , while dihedral angles of [Ni 2 (L 2 ) 2 (CH 3 COO) 2 ] were 60.121 and 57.825 . [38,39] In order to examine deeply the crystal structures of both complexes, remarkable hydrogen bonds ( Figure 2 and Table S1) and weak O-HÁÁÁπ (Ph) interactions ( Figure 3 and Table S2) are discovered between the molecules, which play momentous roles in the dinuclear crystal packing modes. [40] Compared with 2, 1 has three pairs of intramolecular O1-H1ÁÁÁO2, O1-H1ÁÁÁO3, and C12-H12ÁÁÁO4 hydrogen bonds, while there are two pairs of intramolecular O1-H1ÁÁÁO4 and C12-H12ÁÁÁO3 hydrogen bonds with their neighboring atoms, which can form one six-membered ring and one seven-membered ring, respectively.…”