X-ray and infrared spectrum on metal complexes with indolecarboxylic acids

X-ray diffraction and vibrational spectroscopic studies of indolecarboxylic acids and their metal complexes

“…According to the calculated PED by the both DFT calculations, the nZnO1 and nZnO2 stretching vibrations are strongly mixed between themselves and overlap with other modes as can be seen in Table 7. As results from the X-ray, the Zn-O bond distances are longer for [Zn(I3CA) 2 (H 2 O)] n (in the range from 1.977 (4) to 2.519 (4) Å ) [23] than these found in [Zn(I3PA) 2 (H 2 O)] n (in the range from 2.001 (4) to 2.418 (4) Å ) [24]. Therefore, the Zn-O stretching vibrations in [Zn(I3CA) 2 (H 2 O)] n were observed at lower wavenumber (at 470 (IR) and 467 cm À1 (R)) [23] (Table 3 of Supplementary material).…”

“…In [Zn(I3PA) 2 (H 2 O)] n , the Zn-O bond distances for the tridentate chelating-bridging I3PA anionic ligand are 2.001 (4), 2.070 (4) and 2.342 (4) Å and these are shorter than those found for the bidentate chelating I3PA anionic ligand (2.015 (4) and 2.418 (4) Å ) [24]. Moreover, in [Zn(I2CA) 2 (1)#3 interactions (symmetry codes: #2: x, 3/2 À y, À1/2 + z; #3: Àx, 1/2 + y, 3/2 À z) between carboxyl oxygen atoms (1).…”

“…Moreover, in [Zn(I3PA) 2 (H 2 O)] n each zinc centre is six-coordinated by two oxygen atoms of the bidentate chelating I3PA anionic ligand, two oxygen atoms tridentate chelating-bridging I3PA anionic ligand, one oxygen atom tridentate chelating-bridging I3PA anionic ligand from an adjacent [Zn(I3PA) 2 (H 2 O)] unit and water molecule [24].…”

“…In this work, we continue the studies on the synthesis and vibrational spectra of indolecarboxylic acids and their metal complexes [20][21][22][23][24][25]. In this paper, the [Zn(I2CA) 2 (H 2 O) 2 ] n is examined using single crystal X-ray diffraction analysis.…”

“…Basing on the optimized structure for the theoretical model of [Zn(I2CA) 2 (H 2 O) 2 ] n , the normal vibration wavenumbers, IR intensities and Raman activities were calculated.The deficiencies of the computed harmonic force field of I2CA, I2CA-d2 and [Zn(I2CA) 2 (H 2 O) 2 ] n were corrected by selective scale factors. The wavenumbers calculated by the B3LYP and mPW1PW91 methods were scaled, similarly as in our earlier studies[22][23][24][25]. Crystal data and structure refinement for [Zn(I2CA) 2 (H 2 O) 2 ] n…”