Spectroscopic interplay of Co(II) and Pb(II) Salamo complexes: From coordination-induced electronic modulation to antibacterial activity.

Authors

Xiao-Wen Yang, Jia-Yue Teng, Li-Li Wang, Na Tuo, Yang Zhang, Hong-Tao Qiao

Published in

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy. Volume 363. Issue Pt 1. Pages 128356. Jul 02, 2026. Epub Jul 02, 2026.

Abstract

The interplay between coordination-induced electronic modulation and the resulting physicochemical properties of metal complexes is fundamental to coordination chemistry. Herein, we report a comprehensive spectroscopic and theoretical investigation of two novel metal complexes derived from a single-armed Salamo-type ligand H₃L: dinuclear [Co₂(L)(μ₂-OAc)]·EtOH (1) and tetranuclear [Pb₄(L)₂(μ₄-O)]·2CHCl₃ (2). FT-IR, UV-Vis, and fluorescence spectroscopies, together with DFT calculations, unequivocally confirmed metal-ligand coordination and revealed significant electronic restructuring upon complexation. Key spectral signatures-including the disappearance of the OH stretch, redshifts in CN and π → π* transitions, and the emergence of new metal-involved charge-transfer bands-provided direct evidence of ligand-to-metal binding. Notably, the complexes 1 exhibited opposite fluorescence responses: quenching in 1 and enhancement in 2, which were correlated with their DFT-derived HOMO-LUMO gaps (ΔE = 0.972 eV for 1; 2.167 eV for 2) and frontier orbital distributions. Hirshfeld surface and IRI analyses further visualized the non-covalent interactions stabilizing the crystal packing. Importantly, these coordination-induced electronic features translated into distinct biological activities: both complexes showed concentration-dependent antibacterial effects against Escherichia coli and Staphylococcus aureus, with the Pb(II) complex 2 exhibiting superior efficacy. This work establishes a clear spectroscopic-electronic-activity relationship, demonstrating how systematic spectral analysis can guide the rational design of functional coordination compounds.

PMID:
42456245
Bibliographic data and abstract were imported from PubMed on 16 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.