From gallium to thallium: Group 13 one-dimensional polymers

The reactions of EX3 (E = Ga, In, Tl, X = Br or Cl) with pyrazine and pyrazine, 2-carboxylic acid (pyzca-H) affords a series of one-dimensional ladder polymers, [EX3(pyz)]∞ (E = Ga, In, Tl, X = Cl, Br) and the zigzag polymer [InBr2(OH2)2(pyzca)]∞. These polymers are prepared in high yield through a facile synthesis. The structures of each were characterized in the solid state by single crystal X-ray analysis, infrared spectroscopy and where possible NMR. Experimental results reveal how stability of the one-dimensional polymer increases from gallium to thallium, from the air-sensitive gallium polymer to the aqueous preparation and air-stable products of indium and thallium.