  The PTCDA (3,4,9,10-Perylene-tetracarboxylic dianhydride) and the NTCDA
(1,4,5,8-Naphtalenetetracarboxylic dianhydride) are aromatic, stable, planar
and highly symmetric with unusual electrical properties. The PTCDA is a
semiconductor organic crystalline of particular interest due to its excellent
properties and electronic potential that are used in optoelectronic devices and
the NTCDA it is monoclinic and its space group is similar to that of the PTCDA.
Recently, alternate layers of PTCDA and NTCDA were growth forming multiple
structures of quantum wells showing a new class of materials with new optic
lineal properties. Some have assured that their big utilities would be centered
in the construction of diodes and of possible guides of waves. We have carried
out calculations semi-empirical of the electronic structures and of optic
properties of the PTCDA and of the NTCDA that show us that they are structures
highly orderly polymeric, semiconductors in a negative load state (charge
state= -2)
