The effect of partial substitution of chloride by bromide in the 0-D hybrid material (C₄H₁₂N₂)[CuCl₄]·2H₂O: Structural, vibrational, thermal, in silico and biological characterizations

Abstract

A new organic-inorganic hybrid material with copper(II) as the transition metal, piperazine as the organic component and mixed bromide/chloride as halide ions, (C₄H₁₂N₂)[CuBr₄]_0.42[CuCl₄]_0.58·2H₂O (1), has been prepared and crystallographically investigated by single-crystal X-ray diffraction. Unlike the parent chloride or bromide-based materials which adopt the monoclinic system, this mixed halide hybrid material crystallizes in the space group Pnma of the orthorhombic system with the following parameters: a = 12.3496(6) Å, b = 16.3147(11) Å, c = 6.4415(3) Å, V = 1397.83(12) ų and Z = 4. Its 0-D crystal packing is built of isolated entities, a copper(II) ion surrounded by four chloride/bromide ions [CuBr₄]^2- and [CuCl₄]^2-, a diprotonated diamine (C₄H₁₂N₂)²⁺ and free water molecules. Additionally, these entities are linked through different types of intermolecular hydrogen bonds N-H…Br, N-H…Cl, N-H…Ow, Ow-H…Br, Ow-H…Cl, and weak non-covalent interactions C-H…Br and C-H…Cl [Ow = water oxygen]. The thermal decomposition of the precursor proceeds through four stages leading to copper(II) oxide as a final product. The title compound possesses antimicrobial and anti-tumoral effects comparable to two previously described compounds, as assessed by in silico examinations. Compound 1 inhibited in a dose dependent manner, the proliferation of gram negative and positive bacteria and exhibited a microbial lipase inhibition from Candida rugosa.

Keywords:

• Hybrid material
• crystal structure
• supramolecular
• thermal decomposition
• biological activity
• in silico

Disclosure statement

The authors declare no competing financial interest.

Data availability statement

Supplementary crystallographic data for this article in CIF format are available as Electronic Supplementary Publication from the Cambridge Crystallographic Data Centre (CCDC 2124144). The data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge Crystallographic Data Centre. Code availability: WinGX platform, Diamond 3.2 program, Crystal Explorer 17.1, ChemDraw.

Additional information

Funding

This research was funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R95), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.