  The paper presents the first computational experiment on the transformation
of a graphene sheet (graphene molecule Cn) 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 NDA over the
carbon carcass lays the algorithm foundation. The atomically mapped high rank
NDA 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 at the perimeter
of 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.
