Structure and supramolecular arrangement of bis(2,4-bis(trichloromethyl)-1,3,5-triazapenta-dienato)-M(II) [M = Ni(II), Cu(II) and Pd(II)] complexes

The reaction of CCl3CN and ammonia in the presence of metal salts [Ni(CH3COO)2, CuCl2 or Pd(CH3COO)2] in DMSO afforded mononuclear complexes of general formula {M[NH = C(CCl3)NC(CCl3) = NH]2}[(CH3)2SO]2 [M = Ni(1), Cu(2), Pd(3)]. The complexes were characterized by ESI-MS, IR spectroscopy, elemental and single-crystal X-ray diffraction analyses. In 1–3, the metal atom is in an inversion centre and possesses a square-planar coordination environment with two uninegatively charged 1,3,5-triazapentadienato chelators. In the solid state, the (N)H atoms of the ligands interact with oxygen atoms of (CH3)2SO with formation of the six-membered intermolecular resonance assisted hydrogen bonding, while Cl atoms of the CCl3 groups participate in Cl⋯Cl interactions thus generating 2D supramolecular assembly of distinctive geometry.