1. Electronic Structure Studies of 2-Nitrobenzene Sulfinyl Peroxy Intermediates by MNDO Method. As activators of superoxide, 2-nitrobenzene sulfinyl chloride reacts with superoxide to form 2-nitrobenzene sulfinyl peroxy intermediates which are to be good oxidizing agent for olefins, sulfides and sulfines. Electronic structure determination of 2-nitrobenzene sulfinyl peroxy intermediate was performed by MNDO calculations. We will proposed radical sulfinyl peroxy intermediate structure of seven membered ring by MNDO calculations. Seven membered ring structure containing the -O-O- linkage is important structure in oxidation reactions. This structure as a main radical contributor will supported by [2+6] cycloaddition of 2-nitrobenzene sulfinyl component with single oxygen which is generated by superoxide. 2. Bonding Studies of Thallium Dicarbollide Complex by EHT Method In recent year, Do and their co-workers$^{3,4}$ synthesized a series of thallium dicarbollide complexes. The T1-T1 distance of 4.24$\mbox{\AA}$ which is obtained by single crystal X-ray diffraction study indicate the possible existence of T1-T1 bonding interation. In order to clarify the possible bonding nature between thalliums in thallacarborane fragments, EHT calculations have been performed. T1$^+$ ion has bonding interactions with B atoms on the top face of dicarbollide cage but no interactions with C atoms. Also, apparent dimeric formation of $[T1-C_2B_9H_{11}]_2\,^{-2}$ is not due to T1-T1 interactions. The absence of strong antibonding interaction coupled with an existence of electrostatically favorable relative orientation enables crystal packing force to bring two T1 stoms close together.