Nickel(II) polypyridyl Complexes of 2,4,6-Tris(2-pyridyl)-1,3,5-triazine

• Published in: Journal of chemical crystallography 2012-07, Vol.42 (7), p.656-667
• Main Authors: Hadadzadeh, Hassan, Maghami, Mahbobeh, Simpson, Jim, Khalaji, Aliakbar Dehno, Abdi, Khatereh
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Crystallography and Scattering Methods; Inorganic Chemistry; Organometallic Chemistry; Original Paper; Physical Chemistry
• ISSN: 1074-1542; 1572-8854
• DOI: 10.1007/s10870-012-0296-7

The synthesis, purification, characterization, electrochemical properties, and fluorescence quenching of two new mononuclear Ni(II) complexes, [Ni(tptz)(CH 3 OH)Cl 2 ] ( 1 ) and [Ni(tptz) 2 ](PF 6 ) 2 ·CH 3 CN ( 2 ), containing the ligand 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) are described. Solid state structures of both complexes have been determined by single crystal X-ray crystallography. In ( 1 ) and ( 2 ), the Ni(II) metal centers use the major coordination site of the tptz ligand and the coordination geometry around the Ni(II) is a distorted octahedron. The free tptz ligand has three emission bands that are assigned to the 1 ( π – π * ) and 1 ( n – π * ) states. The fluorescence spectra of ( 1 ) and ( 2 ) show that the fluorescence quenching of the tptz fluorophore proceeds via an energy transfer process. Magnetic susceptibility data derived from paramagnetic NMR revealed effective magnetic moments of 2.75 μ B for ( 1 ), and 2.91 μ B for ( 2 ) at room temperature. Cyclic voltammetry of ( 1 ) shows that the Ni(III/II) reduction couple is quasi-reversible whereas in complex ( 2 ), the Ni(II/I) couple indicates an electrochemical (EC) mechanism. Graphical Abstract The synthesis, purification, characterization, electrochemical properties, and fluorescence quenching of two new mononuclear Ni(II) complexes, [Ni(tptz)(CH 3 OH)Cl 2 ] and [Ni(tptz) 2 ](PF 6 ) 2 ·CH 3 CN, containing the ligand 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) are described. Solid state structures of both complexes have been determined by single crystal X-ray crystallography. .