Quinone Oxygen-Coordinated Palladium(II) Complexes with Anthraquinone Ligands Bearing N-Heterocyclic Coordination Sites

✍ Scribed by Toshiyuki Moriuchi; Takuo Watanabe; Isao Ikeda; Akiya Ogawa; Toshikazu Hirao

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 838 KB
• Volume: 2001
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/1099-0682(20011)2001:1<277::aid-ejic277>3.0.co;2-v

✦ Synopsis

The coordination properties of anthraquinone ligands bearing N-heterocyclic coordination sites to divalent palladium, and structural characterization of the quinone oxygen-coordinated palladium(II) complexes are described. The intramolecular NH

The anthraquinone moieties of 1a are oriented in a face-to-face manner to form π-stacks in the crystal, with an interplanar distance of ca. 3.5 A ˚between the neighboring anthraquinone moieties. Complexation of 1a with Pd(OAc) 2 afforded the palladium(II) complex 2a. The quinone oxygen, which is bent out of the anthraquinone plane, is coordinated to the palladium(II) center, which is substituted by the amino nitrogen in a position trans to the pyridyl nitrogen in the crystal structure 2a. 1-(2-Phenylethylamino)-8-[2-(2-pyridyl)ethylamino]-9,10-anthraquinone (1b) was also found to form the 1:1 quinone oxygen-coordinated palladium(II) complex 2b. The single-crystal X-ray structure determination of 2b shows the existence of two independent molecules in the asymmetric unit. These two molecules are present in a good mirror image