EPR investigations on radiation induced chemical transformations in Pd(ClO4)2/i-PrOH/HClO4 system from 77 to 300K
作者:S.C. Tripathi、R.M. Kadam、Manmohan Kumar、J.P. Mittal、S.P. Mishra
DOI:10.1016/j.saa.2005.03.026
日期:2005.12
The EPR studies have been carried out on gamma irradiated samples of Pd(ClO4)2 in 9 M/4M HClO4 in the presence and absence of isopropanol [i-PrOH (5%, v/v)], in the temperature range of 77-300 K. The EPR studies revealed the formation of Pd+ complex, Pd3+ complex and several radicals such as H., OH., ClO3., ClO4. and O3- on radiolysis of these systems. Reduction of Pd2+ to Pd clusters could not be
EPR研究是在存在和不存在异丙醇[i-PrOH(5%,v / v)]的情况下,在77 M的温度范围内,对9 M / 4M HClO4中的Pd(ClO4)2的伽马射线辐照样品进行的。 -300K。EPR研究表明形成了Pd +络合物,Pd3 +络合物和一些自由基,例如H.,OH。,ClO3。,ClO4。和O3-对这些系统进行放射分解。在没有i-PrOH的情况下,无法观察到Pd2 +向Pd簇的还原,并且受辐照样品的升温最终导致Pd2 +复合物的回收。但是,在5%i-PrOH的存在下,会强烈氧化自由基,如OH,ClO3。和ClO4。会被抑制,并生成(CH3)2C.OH自由基以及诸如H的还原物种。在这些强烈还原条件下的EPR光谱显示会形成Pd +络合物,在加热至230 K以上时,歧化成Pd0和Pd2 +络合物,最后导致形成Pd金属聚集体。同时,脉冲放射分解技术已被用作验证EPR观测值的替代方法。