| Abstract
| - The synthesis, characterization, and X-ray structure of a silver(III) complex of an inverted porphyrin isomer, i.e., “N-confused tetraphenylporphyrin”, is reported. A square planar geometry and the diamagnetic nature of the ligand were demonstrated. The unique trianionic coordination, different from that of normal porphyrins, is explicitly discussed
- The synthesis, characterization, and X-ray structure of the first example of an air-stable silver(III) complex of anN-confused tetraphenylporphyrin (5,10,15,20-tetraphenyl-2-aza-21-carbaporphyrin argentate(III) or Ag(III)NCTPP,7) is reported. Crystals of Ag(III)NCTPP·CH2Cl2 belong to the monoclinic space group P21/c (No. 14), with a= 9.038(4) Å, b = 15.097(3) Å, c = 25.578(8) Å, β = 91.32(3)°, and Z = 4. The lengths (Å) of the threesilver−nitrogen and one silver−carbon bonds are inequivalent [Ag−N(1), 2.06(2); Ag−N(2), 2.08(2); Ag−N(3),2.03(2); and Ag−C(17), 2.04(2)], reflecting the asymmetric structure of the NCTPP ligand. The very small distortionfrom a square planar geometry is shown in N−Ag−N and N−Ag−C angles (degrees): N(1)−Ag−N(2), 89.7(8);N(1)−Ag−N(3), 179(1); N(1)−Ag−C(17), 90.3(9); N(2)−Ag−N(3), 89.6(9); N(2)−Ag−C(17), 179(1); and N(3)−Ag−C(17), 90.9(1). The diamagnetic nature of Ag(III)NCTPP was confirmed by 1H and 13C NMR and magneticsusceptibility measurements. Electrochemical and spectrochemical studies revealed that ring reduction and oxidationoccur at −0.72, 1.21, and 1.50 V vs SHE, respectively. The potential role of NCTPP ligand for stabilization ofhigher oxidation states of metal ion is discussed.
|
