Dear team of research gate. I need your guidance. I have few questions in my mind Related to EPFRs. I have no friend or other who had worked on this topic. I try to read and understand research articles but sometimes we need help to understand problems with our friends or teachers.

1st: Can we assume/hypothesis that Nitrogen Centered radicals are also in the category of EPFRs if they persist on surfaces of nano particles (eg. Layered double hydroxides (different metals based partifles), or silica surfaces, or in soil particles. Or clay minerals like MMT etc.)).

2nd: Without aromatic hydrocarbons EPFRs can be originated? For instance, if aromatic hydrocarbons replaced with (nitro-aromatic compounds or aromatic amine or organic aromatic compounds with nitrogen containing functional group eg. nitrobenzene, aniline etc as they are consisted on simple nitrogen containing functional groups with aromatic compounds , )? As for EPFRs formation: lone pair of electrons and deloclaized pie Electrons must be participated (and they are present in the aromatic structures).

3rd: If EPFRs can originate from nitrogen centered racials, till date why nobody had focused on this research area? Scientists had just focused on nitrogen racials, not like carbon/oxygen or oxygenated-carbon centered radicals.

I apologize for my poor understandings.

Thanks.