Halogen-induced electronic modulation and nonlinear optical enhancement in a 6-iodopyridine-2-carboxylate Ni(II) complex: An experimental and DFT study

Şimşek M., Tamer Ö., Vural H., Avcı D., TARCAN E., Latif M., ...Daha Fazla

Journal of Molecular Structure, cilt.1356, 2026 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1356
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1016/j.molstruc.2025.145068
  • Dergi Adı: Journal of Molecular Structure
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Anahtar Kelimeler: CDK8 inhibition, DFT calculations, Frequency-dependent hyperpolarizability, Nickel(II) complex, Pyridine-2-carboxylic acid derivative
  • Kocaeli Üniversitesi Adresli: Evet

Özet

A nickel(II) coordination complex, [Ni(6Ipca)2(4,4dmdpy)], was synthesized using 6-iodo-pyridine-2-carboxylic acid (6IpcaH) and 4,4′-dimethyl-2,2′-dipyridyl (4,4dmdpy). The crystal structure, determined via single-crystal X-ray diffraction, reveals a distorted octahedral geometry around the Ni(II) center. The thermal stability of Ni(II) complex was studied by employing TG-DTA analysis. The structural framework was corroborated by DFT (B3LYP/LanL2DZ) calculations, which also supported vibrational modes observed in FT-IR spectra. Frontier molecular orbital (FMO) and natural bond orbital (NBO) analyses demonstrated enhanced electron delocalization and significant ligand-to-metal charge transfer. Static and frequency-dependent first- and second-order hyperpolarizability parameters (β and γ) revealed substantial nonlinear optical (NLO) responses, with the complex exhibiting higher γ(-ω;ω,0,0) (228.45 × 10–36 esu) values compared to its free ligands. Furthermore, molecular docking simulations against CDK8 kinase showed improved binding affinity (-6.29 kcal/mol, Ki = 24.35 µM) for the Ni(II) complex relative to its uncoordinated ligands, suggesting potential antitumor relevance. These findings position the synthesized Ni(II) complex as a promising multifunctional candidate for NLO applications and biomedical research.