AN AB-INITIO STUDY OF THE MOLECULAR-STRUCTURES OF 1,4,5,8-NAPHTHALENETETRONE AND 5,8-DIHYDROXY-1,4-NAPHTHOQUINONE

The ab initio optimized geometrical and electronic structures of napht halenetetrone and naphthazarin are presented, using the ab initio prog ram GAUSSIAN 90 with the 6-31G basis set. The role of the hydroxyl hyd rogen atoms in stabilizing the planar structure of naphthazarin is hig hlighted by a novel quantum chemical reduction procedure, with which n aphthalenetetrone is converted to naphthazarin by addition of hydrogen atoms.