How graphene is transformed into regular graphane structure

The paper presents the first computational experiment on the transformation of a graphene sheet (graphene molecule C _n) into graphane (CH) _n of regular chairlike structure. The transformation is considered as stepwise hydrogenation of the pristine molecule governed with a particular algorithm. A spatial distribution of the number of effectively unpaired electrons N _DA over the carbon carcass lays the algorithm foundation. The atomically mapped high rank N _DA values are taken as pointers of target atoms at each reaction step. A complete hydrogenation followed by the formation of regular chairlike graphane structure (CH) _n is possible if only all the edge carbon atoms located over perimeter of the pristine sheet are fixed thus simulating a fixed membrane, while the sheet is accessible for hydrogen atoms from both side. The calculations were performed within the framework of unrestricted broken symmetry Hartree-Fock approach by using semiempirical AM1 technique.