MOSSBAUER STUDY ON SOLID-STATE PHOTOLYSIS OF ALKALI TRIS(MALONATO)FERRATES(III)

Solid state photolysis of alkali tris(malonato)ferrates(III), i.e., M- 3[Fe(CH2C2O4)(3)]xH(2)O (M=Li, Na, K, NH4) has been studied employing Mossbauer, infrared and reflectance spectroscopic techniques. The comp lexes were irradiated for 300 hours using a medium pressure mercury va pour lamp of 250 W, Photodecomposition led to the formation of an iron (II) intermediate, M-2[Fe-II(CH2C2O4)(2)(H2O)(2)] (M=Li, Na, K) which on prolonged standing in air oxidized to M[Fe-III(CH2C2O4)(2)(H2O)(2)] . However, in case of ammonium complex, (FeCH2C2O4)-C-II . 2H(2)O once formed remained stable. The extent of photoreduction showed the seque nce: NH4, K > Li > Na. The results have been compared with those of al kali tris (oxalato) ferrates(III).