Supramolecular Self-Assembly of M-IDA Complexes Involving Lone-Pair···π Interactions: Crystal Structures, Hirshfeld Surface Analysis, and DFT Calculations [H₂IDA = iminodiacetic acid, M = Cu(II), Ni(II)]

Abstract

Mononuclear copper(II) and nickel(II) complexes, [(C5H6N2)Cu(IDA)(H2O)] (1) and (C5H7N2)2[Ni(IDA)2(H2O)] (2) [H2IDA = iminodiacetic acid; C5H6N2 = 4-aminopyridine; C5H7N2 = protonated 2-aminopyridine], have been synthesized, and their crystal structures were solved using single crystal X-ray diffraction data. A detailed analysis of Hirshfeld surfaces and fingerprint plots facilitates a comparison of intermolecular interactions, which are crucial in building different supramolecular architectures. Molecules are linked by a combination of N–H···O, O–H···O and C–H···O hydrogen bonds into two-dimensional framework, whose formation is readily analyzed in terms of substructures of lower dimensionality with zero finite zero-dimensional dimeric units as the building blocks within the structures. Moreover, the aromatic molecules that are engaged in lone pair···π interactions with the noncoordinated carbonyl moieties play a crucial role in stabilizing the self-assembly process observed for both complexes. Intricate combinations of hydrogen bonding, lone pair···π and π–π interactions are fully described along with the computational studies.

Synthesis, structure investigation and biological evaluation of 2-thiophene N(4)-phenylthiosemicarbazone and its three metal derivatives

“…In these compounds, π-π interactions are not observed because the adjacent red and blue triangles are not present in the shape index surface. Additionally, π-π interactions are not evident on the curvedness as a large flat region across the molecule [39]. After HL ligands are converted into metal coordination complexes 1-3, the proportion of N-H···S and H···H interaction comprising slightly decrease and C-H···π interaction constituting increase slightly, which suggest metal-chelating has little influence on the shape and flexibility of HL ligand.…”

A new non-centrosymmetric microporous fluorinated iron phosphate: Structural elucidation, spectroscopic study and Hirshfeld surface analysis

“…The intermolecular interactions [31][32][33][37][38][39][40][41][42][43][44] in the crystal structure were quantified using Hirshfeld surface analysis and the associated 2D fingerprint plots [45][46][47] were calculated via the Crystal Explorer 3.0 [48] , which accepts a structure input file in the CIF format. This approach has been built on the electron distribution calculated as the sum of spherical atom electron densities [49,50] .…”

The Role of Halogen Bonding in Controlling Assembly and Organization of Cu(II)-Acac Based Coordination Complexes

“…Examples of synthetic vectors for metal-based supramolecular synthesis include π· · · π [14][15][16], cation· · · π [17], anion· · · π [16,18,19], lone-pair· · · π [16,19,20], and metal· · · π [21,22] interactions, but the most common non-covalent interaction for such ventures is arguably the hydrogen bond [23][24][25][26][27]. Despite the relative frequent use of hydrogen bonds [28,29], such interactions are not always ideal since many hydrogen-bond donors (i.e., amines, oximes, and carboxylic acids) may forge unwanted coordinate-covalent bonds with the metal-ion leading to undesirable assemblies and architectures.…”