Several tetraazaannulenenickel(II) complexes have been synthesized by a one-step template method in a high yield. The replacement of the central metal atom, by other transition metals, is possible only by demetallating nickel complexes. These complexes have been known to possess different chemical and thermal stabilities and electrocatalytic activities by substituents at the methine sites such as psubstituted benzoyl chloride, nicotinyl chloride and acetyl chloride, etc.1-5 These tetraazaannulene complexes were mostly symmetric nickel(II) complexes with substituents at methine sites, while the examples of asymmetric complexes were rarely reported. 3,[5][6][7][8][9] In previous papers we have reported on the reaction, spectral and electrochemical properties and crystal structures of the asymmetric monobenzotetraaza- [14]annulenenickel(II) complexes with five types of psubstituted benzoyl or thiophenecarbonyl groups at the methine sites.10-12 Also, we have studied the crystal structures of asymmetric monobenzotetraaza [14]annulenepalladium(II) and -copper(II) complexes. 13,14 On the other hand, no one has investigated on the reaction, property and crystal structure of the asymmetric palladium(II) complex with para substituted benzoyl groups at the methine sites, as π-conjugated electron system.In the present work, we report that the synthesis and characterization of new asymmetric 3,10-dibenzoylmonobenzotetraaza[14]annulenepalladium(II) complexes, also the electronic effects of the substituents of the p-Xbenzoyl group (X = CH 3 , H, Cl and NO 2 ) on the infrared, electronic absorption and NMR spectra and cyclovoltammograms for the complexes. The structure of complex 2 is identified by X-ray diffraction analysis. Experimental SectionMaterials and measurements. The solvents such as methanol, ethanol, acetonitrile and dichloromethane were refluxed over calcium hydride or sodium metal under nitrogen, and checked for purities by GC just before use. Tetraethylammonium perchlorate (TEAP) used as a supporting electrolyte, was prepared and purified by the method described by Kolthoff and Coetzee. 15