Observation of Te···π and X···X Bonding in para-Substituted Diphenyltellurium Dihalides, (p-Me2NC6H4)(p-YC6H4)TeX2(X=Cl, Br, I; Y=H, EtO, Me2N)-

The supramolecular association of the previously described para-dimethylaminophenyl-substituted diorganotellurium dihalides (<i>p</i>-Me₂NC₆H₄)₂TeX₂ (X = Cl (<b>1</b>), Br (<b>2</b>), I (<b>3</b>)) and (<i>p</i>-Me₂NC₆H₄)RTeCl₂ (R = Ph (<b>4</b>), <i>p</i>-EtOC₆H₄ (<b>5</b>)), was investigated by X-ray crystallography. Unlike almost all other structurally characterized diorganotellurium dihalides, (<i>p</i>-Me₂NC₆H₄)₂TeX₂ (X = Cl (<b>1</b>), Br (<b>2</b>), I (<b>3</b>)) reveal no secondary Te∙∙∙X interactions, but X∙∙∙X interactions. The structure of (<i>p</i>-Me₂NC₆H₄)PhTeCl₂ (<b>4</b>) resembles that of Ph₂TeCl₂ and shows one secondary Te∙∙∙Cl contact, whereas (<i>p</i>-Me₂NC₆H₄)(<i>p</i>-EtOC₆H₄)TeCl₂ (<b>5</b>) exhibits neither secondary Te∙∙∙Cl nor Cl∙∙∙Cl interactions. The unusual structural characteristics of <b>1–5</b> are attributed to the occurrence of intermolecular Te∙∙∙π and π∙∙∙π contacts associated with quinoid π-electron delocalization across the para-dimethylaminophenyl (<b>1–5</b>) and para-ethoxyphenyl (<b>5</b>) groups.<br /><br /><br />