Jump to main content
Jump to site search

Issue 44, 2019
Previous Article Next Article

Chloranilate bridged dinuclear copper(ii) complexes: synanti geometry tuned by the steric factor and supramolecular interactions

Author affiliations


Four dinuclear Cu(II) coordination compounds, [(CuL1)2CA]·CH3OH (1), [(CuL1)2CA]·CH3CN (1A), [(CuL2)2CA] (2) and [(CuL3)2CA] (3) (where, CA = chloranilate anion, HL1 = 2-[1-(2-dimethylamino-ethylimino)-methyl]-phenol, HL2 = 2-[1-(2-methylamino-ethylimino)-methyl]-phenol, HL3 = 2-[1-(methylamino-propan-2-ylimino)-ethyl] phenol, have been synthesized by the self-assembly of copper–Schiff base precursors together with chloranilate anions as bridging ligands. The complexes are characterized by elemental analyses, IR spectroscopy, thermal analyses, and single crystal X-ray crystallography. Structural analyses reveal that complexes 1 and 1A are in the syn-conformation while 2 and 3 are in the anti-conformation with respect to the metal coordinated Schiff-base ligands. Theoretical calculations show that for all three ligands, the anti-conformations are energetically favorable and the unfavourable syn-conformation in 1 or 1A is stabilized through CH⋯π and hydrogen bonding interactions between the [(CuL1)2CA] unit and a co-crystallised solvent molecule. The M06-2X/def2-TZVP level of theory and NCI plot explicitly show that unlike in the case of 2 and 3, which form a 1D supramolecular chain by chelate ring⋯chelate ring π-stacking and cuprophilic interactions between neighbouring dimers, in 1 and 1A, steric interactions between neighbouring dimeric units, incorporated by one extra methyl group of the Schiff-base moiety, restrict these structures into dimeric units. Variable-temperature magnetic susceptibility measurements suggest weak antiferro- and ferromagnetic coupling in 1 (syn-conformation) and 3 (anti-conformation) with coupling constants of −2.11 and 3 cm−1, respectively.

Graphical abstract: Chloranilate bridged dinuclear copper(ii) complexes: syn–anti geometry tuned by the steric factor and supramolecular interactions

Back to tab navigation

Supplementary files

Publication details

The article was received on 08 May 2019, accepted on 02 Oct 2019 and first published on 02 Oct 2019

Article type: Paper
DOI: 10.1039/C9CE00705A
CrystEngComm, 2019,21, 6886-6893

  •   Request permissions

    Chloranilate bridged dinuclear copper(II) complexes: synanti geometry tuned by the steric factor and supramolecular interactions

    P. Kar, A. Franconetti, A. Frontera and A. Ghosh, CrystEngComm, 2019, 21, 6886
    DOI: 10.1039/C9CE00705A

Search articles by author