Synthesis and Spectral Properties of the Complexes of Cobalt(II), Nickel(II), Copper(II), Zinc(II), and Cadmium(II) with 2‐(Thiomethyl‐2′‐benzimidazolyl)‐benzimidazole

Novel Pd(II) and Pt(II) complexes of N,N-donor benzimidazole ligand: Synthesis, spectral, electrochemical, DFT studies and evaluation of biological activity

“…In complexes, the m(NH Bz ) is observed at 3356 cm À1 (Pd-L) and 3355 cm À1 (Pt-L). This confirms that the NH Bz group remains intact in the complexes [3,24].…”

“…Unfortunately, the metal-nitrogen stretching bands could not be distinguished from other ring skeleton vibrations present in this region [3]. The far-IR spectrum of Pd-L complex shows two medium bands at 368 and 362 cm À1 due to m(Pd-Cl) in a cis-square planar structure [24]. Similarly, the platinum complex shows these modes at 372 and 360 cm À1 .…”

Palladium(II) and platinum(II) complexes containing benzimidazole ligands: Molecular structures, vibrational frequencies and cytotoxicity

“…However, the theoretical assignments of these bands are easily assigned by the visualization of the normal mode displacement vectors utilizing the GAUSSVIEW program as tabulated in Table 3. The far-IR spectra of Pd-L 1,2 complexes showed two medium bands at 369 and 363 cm À1 ; which were absent in the free ligands; due to the m(PdACl) in a cis-square planar structure [24]. Similarly, the platinum complexes showed two bands at 372 and 360 cm À1 assign to the PtACl bonds in cis-squareplanar geometry [24].…”

“…By using B3LYP/6-31G(d) method, the scaled calculated value at 3514 cm À1 is assigned to the benzimidazolic NH (NH Bz ) stretching vibration in the benzimidazoles (L 1,2 ). For Pt-L 1 , Pd-L 2 and Pt-L 2 complexes (2-4), the t(NH) Bz bands are observed at 3225, 3227 and 3243 cm À1 , respectively, and are sharper than found in the uncoordinated ligand [3,24] due to the breaking of the intermolecular hydrogen bond. In Pd-L 1 complex (1), the t(NH) Bz vibration mode is embedded by the hydrogen bond effect generated by water of hydration.…”

“…The ligands L 1,2 were prepared by condensation of equimolar quantities of 2-chloromethylbenzimidazole with 4-methoxylaniline (L 1 ) and 4-methylaniline (L 2 ). The reaction mixture was refluxed in ethanol in presence of small amount of sodium iodide for about [18][19][20][21][22][23][24] h. At the end of the reaction period, the mixture was neutralized and the solid was separated by dilution with de-ionized water, and recrystallized from xylene and ethanol, respectively.…”