3-Picoline Mediated Self-Assembly of M(II)–Malonate Complexes (M = Ni/Co/Mn/Mg/Zn/Cu) Assisted by Various Weak Forces Involving Lone Pair−π, π–π, and Anion···π–Hole Interactions

Abstract

Five M(II)-malonate complexes having a common formula (C(6)H(9)N(2))(4)[M(II)(C(3)H(2)O(4))(2)(H(2)O)(2)](PF(6))(2).(H(2)O)(2) (1-5) [where C(6)H(9)N(2) = protonated 3-picoline, M(II) = Ni/Co/Mn/Mg/Zn, C(3)H(4)O(4) = malonic acid, and PF(6)(-) = hexafluorophospahte], have been synthesized and their crystal structures have been determined. Complexes 1-5 were found to be isostructural and protonated 3-picoline has primarily mediated the self-assembly process. Role of a discrete water dimer in complexes 1-5 was also studied. Weaker π-interactions have also played crucial role in stabilizing 1D chain constructed by discrete [M(II)(C(3)H(2)O(4))(2)(H(2)O)(2)] units. An additional copper complex namely, (C(6)H(9)N(2))(4)[Cu(C(3)H(2)O(4))(2)](PF(6))(2) (6) has been synthesized from the same reagents and was found to have a completely different structure from the others. Structures of all the complexes are fully described and compared here. Moreover, the lone pair-π and π-π noncovalent interactions have been analyzed by means of DFT calculations, mainly focusing our attention to the influence of the coordinating metal on the strength of the interactions and the interplay between hydrogen bonding and π-interactions. We also present here Hirshfeld surface analysis to investigate the close intermolecular contacts.

A Combined Theoretical Calculation and Hirshfeld Surface Analysis of Cooperative Non‐covalent Interactions in the Crystal Packing in [Cu(L1)2(EDA)]

“…This complex is associated collectively through hydrogen bonding, C–H···π and π···π interactions, which are also responsible for the strengthening of the molecular assembly and organize it into supramolecular 2D motif in the ab plane (Figure a). In this hydrogen bonded assembly, two monomeric units are rotated (ca.…”

Anion–Cation Recognition Pattern, Thermal Stability and DFT-Calculations in the Crystal Structure of H2dap[Cd(HEDTA)(H2O)] Salt (H2dap = H2(N3,N7)-2,6-Diaminopurinium Cation)

“…The formation energies of the assemblies have been evaluated by calculating the difference between the total energy of the assembly and the sum of the monomers that constitute the assembly, which have been maintained frozen. This methodology has been used by us [39,40] and others [41][42][43][44][45] to analyze supramolecular assemblies in crystal structures. The molecular electrostatic potential was computed at the same level of theory and plotted onto the 0.001 a.u.…”

Elaboration, Structural, Vibrational, DSC Investigations and Hirshfeld Surface Analysis of New Organic–Inorganic Hybrid Compound: [H2mela]Cu2Br6

“…The Hirshfeld surfaces and the fingerprint analysis have been performed to study the nature of interactions and their quantitative contributions towards the crystal packing [37][38][39][40][41][42][43]. The value of d norm is negative or positive when intermolecular contacts are shorter or longer than r vdW [van der Waals (vdW) radii], respectively.…”