Indian Journal of Chemistry Vol. 40A, February 2001, pp. 195-197 Synthesis of phthalocyanine derivatives of the Ru, Rh, Pt and Pd metals under solvent free conditions using microwave irradiation Ahmad Shaabani *, Farzad Bahadoran & Nasser Safari Chemistry Department, Shahid Beheshti University, P.O.Box 19395-4716, Tehran, Iran Received 28 March 2000; revised 22 August 2000 . The phthalocyanine complexes of Ru, RhCI, Pt and Pd are easi ly prepared from phthalic anhydride and the corresponding metal sa lt s by exposing to microwave radiation under solvent free conditions, which reduces reaction time considerably. The y ie ld of metallophthalocyanines is increased by 12-15 % relative to obtained by conventional me th ods. Phthalocyanines are of interest not only as potential sensitizer for photodynamic therapy, but also as dyes and pigments of commercial importance'· 5 . Metallophthalocyanines (M-Pc) are usually prepared by heating metal salts with phthalic anhydride, phthalimide or phthalonitrile (Scheme l) at temperatures more than 200°C for a few A. In Scheme I, metal chlorides are reacted with phthalic anhydride in the presence of urea and ammonium chloride. It is not clear what is the reducing reagent in this process 5 . In such conventional syntheses of metallophthalocyanines, which need longer reaction time and high temperature, yield is often low a nd a mixture of products is often generated from which the pure phthalocyanines may be difficult to obtain. We have earlier reported the synthesis of Cu, Co, Ni, Fe and Zn phthalocyanines from phthalic anhydride 6 a and Cu, Co, Ni, Fe, Zn, Pt, Pd and Ru phthalocynines from phthalonitrile 6 b by microwave method. Here we extend our method to prepare phthalocyanine complexes of Ru, RhCI, Pt, and Pd from phthalic anhydride route in the absence of any solvent ("dry" condition) that reduces the reaction times considerably and increases the yield of products in a process that is accelerated by microwave irradiation 7 . Experimental The microwave oven used was a domestic variety (max. 900W; National model NN-6653) with fi ne power settings (two of which were used for this experiment: the high 100% wattage and the medium 70 % wattage). Elemental analyses were performed using a Heraeus CHN-0 rapid analyzer. IR spectra were recorded with a Shimadzu IR-470 spectrophotometer. Uv/Vis spectra were recorded with a Shimadzu 2100 spectrophotometer. Purities of the products were confirmed by comparison with literatures values 8 • 14 • In a typical procedure for PdPc, phthalic anhydride (2.65 g, 18 mmol), urea (5.55 g, 92 mmol), ammonium chloride (0.92 g, 17 mmol), ammonium molybdate (0.005 g, 4.2x 10- 3 mmol as catalyst) and palladium chloride (0.108 g, 0.6 mmol) were finely ground. These ground materials were pl aced in a beaker and irradiated in the microwave oven at high power for 4 min. As the reaction started, the power of the oven was turned to medium and samples irradiated until the reaction was complete (about 2 min.). The product was ground and washed with 250 ml of hot water and dried (0.496 g). The crude PdPc was subsequently reprecipitated three times from Scheme 1