Detailed theoretical analysis of the Cu^II···Cl interaction nature in a series of three-component supramolecular heterometallic {Cu^II}{Sn^IV} cocrystals with the general formula of (H₂ED)²⁺·2[CuL]·[SnX_nCl_6–n]^2– [H₂L = N,N′-ethylenebis(3-OR-salicylaldimine), R = Me (H₂L¹) or Et (H₂L²); ED = 1,2-ethylenediamine; X = Me, Et, Buⁿ, or Ph; n = 2 or 0] was performed. The neutral metal complex [CuL] and the [SnX_nCl_6–n]^2– anion in their crystal structures (1–8) interact via a Cu^II···Cl interaction, along with H-bonds. Structural comparison reveals that the Cu^II···Cl interaction (2.886–3.247 Å) in (H₂ED)²⁺·2[CuL]·[SnX₂Cl₄]^2– cocrystals (1–6, type A, X = Me, Et, Buⁿ, or Ph) is shorter than that (3.407–3.454 Å) in the inorganic tin(IV) containing versions (H₂ED)²⁺·2[CuL]·[SnCl₆]^2– (7 and 8, type B), despite both types (A and B) having similar molecular or supramolecular arrangements. Interaction energies among the components (cation, neutral, and anion) present a triangular energy framework. An attempt has been made to find a correlation between the interaction energies and the concerned noncovalent interactions. Further, the nature of Cu^II···Cl interaction in 1 and 7 (as representatives of types A and B, respectively) was understood as being a semicoordination bond by DFT calculations with application of the QTAIM, ELF, IGM, EDD, and CDF analyses and IBSI calculation. The ranges of the Cu^II···Cl interactions in these cocrystals and in other related systems are also discussed. Preliminary catalytic studies on Strecker type cyanation revealed that the catalytic ability of the chloro-tin(IV) precursor, i.e., [Sn(Me)₂Cl₂] or [SnCl₄]·5H₂O, was greatly reduced upon conversion into the corresponding dianion, i.e., [Sn(Me)₂Cl₄]^2– or [SnCl₆]^2– in 1 or 7, respectively.

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