Metal Complexes of 2-[1,2,3-thia(and selena)diazol-4-yl]pyridine and an Unusual Silver-induced Selenadiazole Rearrangement

Abstract

Complexes of 2-(1,2,3-thiadiazol-4-yl)pyridine (3) and 2-(1,2,3-selenadiazol-4-yl)pyridine (4) with palladium(II), nickel(II), ruthenium(II), copper(II), and silver(I) reagents are reported. In general, these ligands chelate to the metal but are curiously prone to positional disorder in the X-ray crystal structures of their complexes. With silver tetrafluoroborate, ligand (3) forms an ordered M₂L₄ complex that contains an unsupported Ag–Ag interaction. Treatment of (4) with excess silver nitrate leads to an intriguing molecular rearrangement that produces a silver complex of 3-formyl-1,2,3-triazolo[1,5-a]pyridine.