First Homoleptic Complexes of the Tridentate Pyridine‐2,6‐ditetrazolate Ligand

The synthesis and spectroscopic characterisation of a series of homoleptic complexes of the tridentate pyridine-2,6-di(5tetrazolate) ligand (pydtz 2– ) with Co II ,N i II ,C u II and Zn II are reported. Single-crystal XRD data reveals the formation of octahedrally configured complexes [M(pydtz)2] 2– for M=Z n or [M(Hpydtz)(pydtz)] – for M = Co or Ni, whereas for M = Cu a polymeric structure [Cu(pydtz)(EtOH)]n crystallised. In the latter, alternate short and long Cu···Cu distances were found. Magnetic measurements and electron paramagnetic resonance (EPR) spectroscopy reveal noncoupled S = 1/2 Cu II ions for [Cu(pydtz)(EtOH)]n, S = 1/2 low-spin configuration for the Co II complex and an S = 1 ground state for the Ni II