Magnetic susceptibility and EPR spectra of Co(II) 2-N substituted N-confused porphyrin: Co(2-NCH2-p-C6H4-isoC3H7-21-CH2-p-C6H4CH3-NCTPP)Cl

The crystal structures of diamagnetic (2-aza-2-[p-(isopropyl)benzyl]-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′,N″) nickel(II) [Ni(2-NCH2-p-C6H4-isoC3H7NCTPP); 8] and paramagnetic chloro(2-aza-2-[p-(isopropyl)benzyl]-5,10,15,20-tetraphenyl-21-p-xylyl-21-carbaporphyrinato-N,N′,N″) cobalt(II) [Co(2-NCH2-p-C6H4-isoC3H7-21-CH2-p-C6H4CH3-NCTPP)Cl; 9] were determined. The coordination sphere around Ni2+ ion in 8 is distorted square planar (DSP), whereas for Co2+ in 9, it is distorted tetrahedron (DT). The effective g value, geff = [gx(eff), gy(eff), gz(eff)] = [1.92, 3.73, 6.18] measured from the perpendicular polarization of X-band EPR spectrum for 9 in toluene at 4 K is consistent with a 4A2(F) ground term for a high spin mononuclear cobalt(II) (S = 3/2) in 9. The magnitudes of axial (D) and rhombic (E) zero-field splitting (ZFS) for the mononuclear Co(II) in 9 were determined approximately as 29.35 and 6.46 cm−1, respectively by paramagnetic susceptibility measurements and conventional EPR spectroscopy.

The inner C-p-xylyl-substituted cobalt(II) complex of a 2-N substituted N-confused porphyrin (9) were synthesized from the reaction of 2-NCH2-p-C6H4-isoC3H7NCTPPH (7) and CoCl2·6H2O in p-xylene and the structure was revealed by single-crystal X-ray analysis.Figure optionsDownload as PowerPoint slide