Molecular structure and spectral properties of ethyl 3-quinolinecarboxylate (E3Q) and [Ag(E3Q)2(TCA)] complex (TCA=Trichloroacetate)

Spectrochim Acta A Mol Biomol Spectrosc. 2014 Sep 15:130:453-65. doi: 10.1016/j.saa.2014.04.045. Epub 2014 Apr 20.

Abstract

A new [Ag(E3Q)2(TCA)] complex; (E3Q=Ethyl 3-quinolinecarboxylate and TCA=Trichloroacetate) has been synthesized and characterized using elemental analysis, FTIR, NMR and mass spectroscopy. The molecular geometry and spectroscopic properties of the complex as well as the free ligand have been calculated using the hybrid B3LYP method. The calculations predicted a distorted tetrahedral arrangement around Ag(I) ion. The vibrational spectra of the studied compounds have been assigned using potential energy distribution (PED). TD-DFT method was used to predict the electronic absorption spectra. The most intense absorption band showed a bathochromic shift and lowering of intensity in case of the complex (233.7 nm, f=0.5604) compared to E3Q (λmax=228.0 nm, f=0.9072). The calculated (1)H NMR chemical shifts using GIAO method showed good correlations with the experimental data. The computed dipole moment, polarizability and HOMO-LUMO energy gap were used to predict the nonlinear optical (NLO) properties. It is found that Ag(I) enhances the NLO activity. The natural bond orbital (NBO) analyses were used to elucidate the intramolecular charge transfer interactions causing stabilization for the investigated systems.

Keywords: DFT; Intramolecular charge transfer; NBO; NLO; NMR; Vibrational spectra.

MeSH terms

  • Carboxylic Acids / chemistry*
  • Ligands
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Molecular Conformation
  • Molecular Structure
  • Optics and Photonics
  • Quinolines / chemistry*
  • Silver / chemistry*
  • Software
  • Spectrophotometry, Infrared
  • Spectrophotometry, Ultraviolet
  • Spectroscopy, Fourier Transform Infrared
  • Static Electricity
  • Trichloroacetic Acid / chemistry*
  • Vibration

Substances

  • Carboxylic Acids
  • Ligands
  • Quinolines
  • Silver
  • Trichloroacetic Acid