Syntheses and Characterization of Molybdenum/Zinc Porphyrin Dimers Bridged by Aromatic Linkers

Abstract

Two new heterobinuclear porphyrin dimers, namely [{MoVIO2}‐DBPA‐Zn] (1; H4DBPA = N,N′‐dibenzylidenebis[4‐(10,15,20‐triphenyl‐21H,23H‐porphin‐5‐yl)phenylamine]) and [{MoVIO2}‐PBDA‐Zn] (2; H4PBDA = N,N′‐bis[4‐(10,15,20‐triphenyl‐21H,23H‐porphin‐5‐yl)phenyl]‐1,3‐benzenedicarboxamide), have been synthesized. These bis(porphyrin)s were obtained by treating 5‐(p‐aminophenyl)‐10,15,20‐triphenylporphyrinatomolybdenum and ‐zinc with benzene‐1,4‐dicarboxaldehyde or benzene‐1,3‐dicarboxylic acid. They have been characterized by UV/Vis, IR, X‐ray photoelectron, luminescence, and 1H NMR spectroscopy, and their TG‐DTA behavior and molar conductances have also been determined. Th cis‐dioxomolybdenum(VI) unit in these complexes is contained in one of the porphyrin moieties and zinc(II) ion is tetracoordinated in the other. Their electrochemical properties have also been investigated in detail. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Understanding Oxygen Activation on Metal- and Nitrogen-Codoped Carbon Catalysts

“…The Mo 3d spectrum reveals pure Mo­(VI), without any lower oxidation states (e.g., no carbides). The broad peak at 232.5 eV could correspond to amorphous MoO 3 , or to Mo VI –N x clusters . Finally, the Pb 4f spectrum shows peaks typical to PbO, albeit shifted 0.5 eV to higher energies .…”

“…The broad peak at 232.5 eV could correspond to amorphous MoO 3 101,102 or to Mo VI −N x clusters. 103 Finally, the Pb 4f spectrum shows peaks typical to PbO, albeit shifted 0.5 eV to higher energies. 104 This shift (see Figure S4) is assigned to unreacted Pb(NO 3 ) 2 , 105,106 which dissolves during catalysis.…”