Synthesis and EPR studies of vanadyl tetrakis(selenodiazole)porphyrazine

Abstract

Tetrakis(selenodiazole)porphyrazine and its vanadyl (VO 2? ) complex have been prepared and characterized by FT-IR, UV-vis, and MALDI-MS. The magnetic properties of the complex have been investigated by EPR spectroscopy.

Synthesis and EPR studies of soluble vanadyl octakis(4-tert-butylbenzylthio) porphyrazine

“…The FTIR spectrum of VOPz (3) showed a stretch of the t-butyl peak at 2863-2956 cm À1 and aromatic C-H peaks at 3028 cm À1 , which are very similar with the literature (M = Cu, Co, Zn) as expected [12,13]. The absence of N-H peaks and the presence of a V=O peak at 990 cm À1 are evidences for the formation of VOPz [31]. In 1 H NMR spectra of 1 and 2, chemical shifts corresponding to tert-butyl protons are the expected singlet at 1.3 ppm in TBBTMNT, 1.14 ppm in 1, and 1.33 ppm in 3.…”

“…UV-vis spectra of metallo-porphyrazines 1 and 3 (4 Â 10 À5 M solutions in chloroform) prepared in the present work exhibited intense single Q-band absorption of the π → π ⁄ transition at 675 and 692 nm and B-bands at 378 and 352 nm, respectively (figure 2). The Q-band absorption of VOPz in chloroform is a broad single peak which indicates axial ligation of chloroform at the vacant site of vanadium with similar symmetry to the Mg(II) complex [31]. The change of symmetry of porphyrazine core from D 4h for metallo-species to D 2h in metalfree 2 shows a split Q-band at 652 and 711 nm, as expected [4,13,38].…”

“…They are promising candidates for realizing optical and electronic functional devices; transparent organic thin-film transistors [28]; hole transport layers with increased carrier density and conductivity [29]; and important biological functions in the case of diabetes with oxovanadium (VO 2+ ) ions [30]. Therefore, electronic and magnetic properties of these compounds should be sensitive to the nature of substituent ions and peripheral complexes [15,31].…”

“…This has been resolved by the addition of solubilizing groups such as tert-butyl on the periphery [31,32]. The tert-butyl substituted phthalocyanine and analogues provide high solubility in organic solvents [32] and extends the potential applications of these macromolecules, such as good volatility in vacuum and they were shown to be good candidates for the preparation of thin films by vacuum thermal evaporation [33].…”

Oxovanadium(IV) complexes based onS-alkyl-thiosemicarbazidato ligands. Synthesis, characterization, electrochemical, and antioxidant studies

“…McGarvey. [39] In most VO 2+ -centered complexes, the P value has been obtained around 140 G. [40] In our calculations, we used the theoretical one and β 2 2 = 0.93 as used in the literature for several VO 2+ complexes, for example, trisodium citrate dihydrate (Na 3 C 6 H 5 O 7 · 2H 2 O) [41] and TSeDPzH 2 , [42] and κ = 0.9 was adopted (Table 2). Besides, the isotropic parameters A 0 s were calculated using Equation (4) above.…”