研究了苯酚和苯胺类化合物在不同pH下对光泽精-H2O2-Co2+体系化学发光(Chemiluminescence,CL)的影响。在NaHCO3-Na2CO3缓冲体系中,具有吸电子基团或两个-OH处于间位的化合物在中间的pH(即pH9.9)呈现增强作用,其他的化合物呈现抑制作用;在NaOH体系中,所有的化合物都呈现抑制作用。化合物对光泽精CL增强和抑制作用与化合物的结构、介质、以及介质的pH有关。通过研究光泽精CL反应混合物的荧光光谱以及光泽精体系的CL光谱等,提出了其增强和抑制作用的可能机理。苯酚和苯胺类化合物与光泽精竞争消耗溶液中的H2O2/HO2-,导致了化合物对光泽精CL的抑制作用;同时,苯酚和苯胺类化合物可以作为亲核试剂与光泽精反应形成一种加成物,这种加成物与光泽精相互作用生成光泽精自由基,然后与溶解氧反应产生CL,从而增强光泽精的CL。这两种作用相互竞争,导致了不同的条件下,化合物对光泽精CL增强和抑制作用的出现。
The effect of phenol and aniline derivatives on the lucigenin-H2O2-Co^2+ chemiluminescence (CL) at different pH was studied. In NaHCO-Na2CO3 medium, some compounds enhanced the lucigenin CL while others inhibited the lucigenin CL. In NaOH medium, all tested compounds inhibited the lucigenin CL. It was found that the magnitude of enhancement and inhibition by tested compounds was related to their molecular structures, media, and pH. The fluorescence spectra of the system after the CL reaction and the CL spectra of the lucigenin system were studied. The possible mechanisms for CL enhancement and inhibition have been proposed. On the one hand, the competition of phenol and aniline derivatives with lucegenin for H2O2/HO2^- led to the inhibition. On the other hand, the nucleophilic adducts of lucigenin formed by the reactions of some phenol and aniline derivatives with lucegin reacted with lucigenin to give rise to lucigenin radicals, followed by the reactions with the dissolved oxygen to give CL, resulting in the enhancement. The competition of these two routes led to the CL enhancement or inhibition under different conditions.