Synthesis, crystal structures and spectroscopic characterization of Co(II) bis(4,4′-bipyridine) with meso-porphyrins α,β,α,β-tetrakis(o-pivalamidophenyl) porphyrin (α,β,α,β-TpivPP) and tetraphenylporphyrin (TPP)

Abstract

The reaction of the starting materials [ Co II ( Porph )] (Porph = α,α,α,α-tetrakis(o-pivalamidophenyl)porphyrin (TpivPP) and the meso-tetraphenylporphyrin (TPP)) with an excess of 4,4′-bipyridine in chlorobenzene leads to the creation of two cobalt(II) derivatives: [ Co II (α,β,α,β- TpivPP )(4,4′- bpy )2]· C 6 H 5 Cl · C 6 H 14(1) and [ Co II ( TPP )(4,4′- bpy )2]·2 bpy (2). These compounds have been characterized by UV-vis, IR, 1 H NMR and MALDI-TOF spectroscopy. The proton NMR spectra of (1) and (2) clearly indicated that these derivatives are paramagnetic while the UV-vis data confirmed creation of a new six-coordinated or penta-coordinated Co ( II )-meso-porphyrin complexes by displaying red shifted Soret bands. The determined X-ray structures of (1) and (2) show that in the solid state these species are considered as coordination polymers which consist of 1D chains of alternating [ Co II ( Porph )] and 4,4′-bipyridine molecules located at the axial positions of the cobalt(II) coordination sphere. The coordination geometry of Co ( II ) in (1) and (2) is octahedral; the porphyrin (TpivPP or TPP) acts as a tetradentate chelating ligand with four nitrogen atoms from the pyrrole moieties occupying the equatorial positions along the porphyrin core. The N -donor atoms of the 4,4′-bipyridine create the axial ligands. It is noteworthy that for complex (1) the starting porphyrin is the α,α,α,α-TpivPP atropisomer but the final coordination polymer contains the α,β,α,β-TpivPP conformer.

A new cobalt(ii)meso-porphyrin: synthesis, characterization, electric properties and application in the catalytic degradation of dyes

“…Fig. 14 shows the advancement of catalytic degradation of the dyes monitored by the reduction in absorbance at the respective l max values of the dyes at different times (10,30,60,120, 180 and 240 min). Fig.…”

Development of iridium porphyrin arrays by axial coordination through N-bidentate ligand: Synthesis and evaluation of the optical, electrochemical and thermal properties

“…The success of this reaction was evidenced essentially by the wavenumber corresponding to the stretching of the C-N and C-C bonds, of the bipyridine moiety, around 1593, 1470 and 1407 cm À1 , and the absence of the band of CO at 2045 cm À1 [16,29]. The axial coordination of aza conjugated ligands, as bipyridine, has influence on the complexes vibrational waves, where the C@C stretch either on phenyl and porphyrin, the C-H bend in the phenyl and the C-N stretch in porphyrin are shifted to lower or higher energies [16,34].…”

Crystal structure of bis(4-nitroaniline-κN1)(5,10,15,20-tetraphenylporphyrinato-κ4N)cobalt(III) chloride dichloromethane monosolvate

“…For the synthesis of the title compound, see: Madure & Scheidt (1976). For related structures, see: Dhifet et al (2010); Konarev et al (2003); Jentzen et al (1995); Mansour et al (2013); Zhang et al (2005); Feng (2012). For a description of the Cambridge Structural Database, see: Allen (2002 Hydrogen-bond geometry (Å , ).…”

“…The average equatorial cobalt-pyrrole N atom distance [Co-Np = 1.982 (2) Å] is (i) longer than the one of the [Co II (TPP)] complex (Konarev et al, 2003) [Co-Np = 1.923 (4) Å which presents a very ruffled porphyrin core (Jentzen et al, 1995) (Mansour et al, 2013) which exhibits a practically planar porphyrin core. Thus, our synthetic derivative should display a planar conformation of the porphyrin core which is confirmed by the very small desplacements of the atoms of the porphyrin core with respect to the CoN 4 C 20 mean plane [between -0.052 (1) Å and 0.041 (1) Å].…”