Different orbital occupation by an added single electron in 1,10-phenanthroline and its 3,4,7,8-tetramethyl derivative. Evidence from electron paramagnetic resonance spectroscopy of the anion radicals and of their dimesitylplatinum(II) complexes. X-ray molecular structure of dimesityl(1,10-phenanthroline)platinum(II). Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry, 12:2121--2126, 1995. [PUMA: ESR anion complex crystal dimesityl mesityl mol phenanthroline platinum platinum;phenanthroline potential;radical redox structure]