ONN-complexes of dioxomolybdenum(VI) with 2-hydroxy-1-naphthaldehyde S-ethyl-4-H/phenyl-thiosemicarbazones: Crystal structure, electrochemistry and in situ spectroelectrochemistry

Duman S., Kizilcikli I., KOCA A., AKKURT M., Ulkuseven B.

POLYHEDRON, cilt.29, sa.15, ss.2924-2932, 2010 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 29 Sayı: 15
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1016/j.poly.2010.07.022
  • Dergi Adı: POLYHEDRON
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.2924-2932
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Hayır

Özet

Neutral dioxomolybdenum(VI) complexes of dibasic 2-hydroxy-1-naphthaldehyde S-ethyl-4-H/phenyl-thiosemicarbazones (H: L-1, C6H5: L-2) have been synthesized. The complexes. [MoO2L1(ROH)] (1a-d) and [MoO2LII(ROH)] (2a-d) (R: CH3, C2H5, C3H7, C4H9) were characterized by elemental analysis, electronic. IR and H-1 NMR spectra. X-ray crystal studies indicated a distorted octahedral geometry for [MoO2(L-1)(C2H5OH)] (1b) and [MoO2(L-2)(CH3OH)] (2a). The Mo-O bond lengths of the MoO22+, moieties are almost the same in the monoclinic crystal structures of complexes 1b and 2a, and the MoO2 cores have a cis-dioxomolybdenum structure with angles ca. 105 angstrom While 1b crystallizes in the space group C2/c, 2a crystallizes in the space group P2(1)/n. The electrochemical behaviors of the ligands and their complexes 1b and 2a were studied using cyclic voltammetry and square wave voltammetry. The half-wave potentials (E-1/2) are significantly influenced by the central metal ions, the nature of the substituents on the thiosemicarbazones, and the electronic character of the ligands, which are the important factors that control redox potentials. In situ spectroelectrochemical studies were employed to determine the spectra of the electrogenerated species of the complexes and to assign the redox processes. The colors of the electrogenerated species were determined with in situ electrocolorimetric measurements. (C) 2010 Elsevier Ltd. All rights reserved.

Neutral dioxomolybdenum(VI) complexes of dibasic 2-hydroxy-1-naphthaldehyde S-ethyl-4-H/phenyl-

thiosemicarbazones (H: L1, C6H5: L2) have been synthesized. The complexes, [MoO2LI(ROH)]

(1a–d) and [MoO2LII(ROH)] (2a–d) (R: CH3, C2H5, C3H7, C4H9) were characterized by elemental analysis,

electronic, IR and 1H NMR spectra. X-ray crystal studies indicated a distorted octahedral geometry

for [MoO2(L1)(C2H5OH)] (1b) and [MoO2(L2)(CH3OH)] (2a). The Mo–O bond lengths of the

MoO2

2ş moieties are almost the same in the monoclinic crystal structures of complexes 1b and

2a, and the MoO2 cores have a cis-dioxomolybdenum structure with angles ca. 105 Å. While 1b crystallizes

in the space group C2/c, 2a crystallizes in the space group P21/n. The electrochemical behaviors

of the ligands and their complexes 1b and 2a were studied using cyclic voltammetry and square

wave voltammetry. The half-wave potentials (E1/2) are significantly influenced by the central metal

ions, the nature of the substituents on the thiosemicarbazones, and the electronic character of the

ligands, which are the important factors that control redox potentials. In situ spectroelectrochemical

studies were employed to determine the spectra of the electrogenerated species of the complexes

and to assign the redox processes. The colors of the electrogenerated species were determined with

in situ electrocolorimetric measurements.