A 13C and 1H NMR spectroscopic investigation of the structure of the iminium ion with a dipolar form in metal complexes of 2-N-substituted N-confused porphyrins.

The crystal structures of chloro(2-aza-2-ethoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′N′′) zinc(II) [Zn(2-NCH2COOC2H5NCTPP)Cl; 4], (2-aza-2-ethoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′N′′) palladium(II) [Pd(2-NCH2COOC2H5NCTPP); 5], bromo(2-aza-2-ethoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′N′′) manganese(III) [Mn(2-NCH2COOC2H5NCTPP)Br; 6], [2-aza-(3′-phenoxypropyl)-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′N′′] nickel(II) [Ni(2-NCH2CH2CH2OC6H5NCTPP); 7] and chloro(2-aza-2-methoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′N′′) zinc(II) [Zn(2-NCH2COOCH3NCTPP)Cl; 8] have been established. The g value of 9.54, which was measured from the parallel polarization of the X-band EPR spectra in CHCl3 at 4 K, is consistent with the high spin mononuclear manganese(III) centre (S = 2) in 6.