9-Allyl-1,7-dicarbadodecaborane as a dienophile in aza Diels–Alder reactions of 1,2,4-triazines: synthesis of pyridines bearing a carborane cage

The synthesis of pyridine and bipyridine derivatives of m-carborane via aza Diels–Alder reaction of 1,2,4-triazines with 9-allyl m-carborane and their structural characterization and photophysical properties are described. The products 3- and 4-(m-carborane-9-ylmethyl)-2,2′-bipyridines form Zn(II) complexes on reaction with ZnCl2, which increases significantly their fluorescence intensity.