Abstract
The problem of benzene molecular structure has not been solved for more than 100 years. This research proposes a new concept of covalent bond based on the existing theory: each electron shared by multiple atom nuclei corresponds to a half-valent bond. The half-valent bond can be formed between the spacer carbon atoms of the benzene ring. In this way, a new theory was established. Quantum mechanical calculations can quantitatively explain experimental results, such as the hydrogenation heat and ultraviolet spectrum of benzene. Using the dotted line to indicate the half-valent bond, benzene molecular structural forms and chemical reaction formulas as will as its dozens of homologues and derivatives are designed easily. The method not only has a wide range of adaptability, but can also record the chemical reaction process. If several stacked benzene rings can form a benzene tube under the guidance of the new theory, calculated thickness of the three-layer benzene tube is very close to the thickness of graphene. Therefore, referring to other characteristics of graphene, it is considered to be more like a three-layer structure.