Synthesis, Spectral, X‐Ray Diffraction, DFT, and Nematicidal Activity of Mixed Ligand Complexes of Ethyl 2‐(2‐Hydroxybenzylidine)‐Hydrazine Carboxylate and 1,10‐Phenanthroline with Some Transition Metals

Abstract

In this work, mixed ligand complexes derived from ethyl 2‐(2‐hydroxybenzylidine)‐hydrazine carboxylate (HL) and 1,10‐phenanthroline (Phen) as ligands were synthesized and their structures elucidated by elemental analysis, infrared (IR), electronic,1H NMR, and mass spectra, X‐ray diffraction (XRD), magnetic susceptibility measurements, and TG/DTG analyses. The analytical and spectral data support the formation of the complexes with the central ion in each complex six‐coordinated and a slightly distorted octahedral geometry. The IR spectra showed that HL and Phen ligands act as neutral bidentates. The XRD patterns of the complexes showed their crystalline nature. The calculated bond length and the force constant F(U═O) in the uranyl complex are 1.738 Å and 685.90 Nm−1, respectively. The molar conductance values of the synthetic complexes in DMF were found to be in the range 5.00–274.06 S cm2/mol at room temperature. The thermodynamic parameters were evaluated by using the Coats–Redfern (CR) and Horowitz–Metzeger (HM) methods. Theoretical molecular structures were investigated by the density functional theory/B3LYP method using the Gaussian 98 W basis set. The nematicidal activity of the ligands and its metal complexes was also studied.

LModeA-nano: A PyMOL Plugin for Calculating Bond Strength in Solids, Surfaces, and Molecules via Local Vibrational Mode Analysis

“…It is worth noting that the force constant has already been used by chemists to quantify and compare chemical bond strengths in solids in seven different ways since the 1950s as follows. (I) While the phonon mode concerning the chemical bond of interest is highly localized, the equation of the classical vibrational mode is used to calculate force constant k from the vibrational frequency ν which can be either experimentally measured or calculated where μ is the reduced mass of the bonded atom pair A–B. − This method is useful when experimental vibrational spectra are available; however, it has limited applicability because vibrational modes are in general delocalized. , (II) A closely related approach is to employ the force field models consisting of force constant parameters that can best reproduce experimentally measured vibrational frequencies, and then the refined force constant values of chemical bonds are directly used as bond strength descriptors. − This method is feasible for simple solid structures because only a few parameters are needed, but for complicated structures, the parameter optimization becomes rather difficult. In addition, this force field based method to calculate vibrational spectra has become obsolete due to the availability of DFT methods in calculating the lattice vibrations .…”