Structural diversity in the coordination of 1,4‐dihydro‐1,4‐diarsinine as a cyclic ditopic organoarsenic ligand to metal ions

<jats:title>Abstract</jats:title><jats:p>A number of different complexation structures of <jats:italic>cis</jats:italic>‐1,4‐dihydro‐1,4‐dimethyl‐2,3,5,6‐tetrakis(<jats:italic>t</jats:italic>‐butoxycarbonyl)‐1,4‐diarsinine (<jats:italic>cis</jats:italic>‐DHDA<jats:italic>t</jats:italic>Bu) with gold(I) and iridium(III) were synthesized and characterized by <jats:sup>1</jats:sup>H, <jats:sup>13</jats:sup>C NMR spectra, X‐ray crystallography, and elemental analysis. Mono‐ and di‐nuclear gold(I) chloride complexes with <jats:italic>cis</jats:italic>‐DHDA<jats:italic>t</jats:italic>Bu were obtained by simple addition of gold(I) chloride to <jats:italic>cis</jats:italic>‐DHDA<jats:italic>t</jats:italic>Bu. A hetero‐trinuclear gold‐platinum‐gold complex (PtAu<jats:sub>2</jats:sub><jats:italic>Cl</jats:italic><jats:sub>4</jats:sub>(<jats:italic>cis</jats:italic>‐DHDA<jats:italic>t</jats:italic>Bu)<jats:sub>2</jats:sub>) was obtained by complexation of a mononuclear platinum(II) complex (<jats:italic>trans</jats:italic>‐PtCl<jats:sub>2</jats:sub>(<jats:italic>cis</jats:italic>‐DHDA<jats:italic>t</jats:italic>Bu)<jats:sub>2</jats:sub>), which was obtained by complexation of <jats:italic>cis</jats:italic>‐DHDA<jats:italic>t</jats:italic>Bu with a half‐equimolar amount of PtCl<jats:sub>2</jats:sub>(PhCN)<jats:sub>2</jats:sub>, with a twice‐equimolar amount of gold(I) chloride. An iridium(III) complex with <jats:italic>cis</jats:italic>‐DHDAtBu (IrCl<jats:sub>3</jats:sub>(<jats:italic>cis</jats:italic>‐DHDA<jats:italic>t</jats:italic>Bu)<jats:sub>2</jats:sub>) was prepared from hydrated iridium(III) chloride and <jats:italic>cis</jats:italic>‐DHDAtBu. The complex comprises a five‐membered chelate <jats:italic>cis</jats:italic>‐DHDAtBu and an usual monodentate <jats:italic>cis</jats:italic>‐DHDAtBu. The interior angles at around the arsenic and the As–C—C bond angles were significantly varied from 113.4° to 129.4° in the present crystal. These observations suggest that the flexibility of the bond angles at around the arsenic center is inherent property in the present organoarsenic compounds. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:16–26, 2012; View this article online at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://wileyonlinelibrary.com">wileyonlinelibrary.com</jats:ext-link>. DOI 10.1002/hc.20747</jats:p>