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

Abstract

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 ÁCH 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 (p-p * ) and 1 (n-p * ) 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 l B for (1), and 2.91 l 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.

Synthesis, characterization and immobilization of a novel mononuclear vanadium (V) complex on modified magnetic nanoparticles as catalyst for epoxidation of allyl alcohols

“…Since the reported separation between υ(C = N) and υ(C = C) is close to 20 cm ‐1 for polypyridyl compounds, therefore observation of these bands may be due to either C = N and C = C vibrations of triazine and polypyridyl rings. The observed vibrations are consistent with those reported before [46b, 49] . The FT‐IR spectrum of [VO 2 (bpca)] complex 1 shows two sharp bands at 1723 and 1322 cm ‐1 due to the C = O and C–N stretching vibrations, respectively.…”

Synthesis, characterization and luminescent properties of europium complexes with 2,4,6‐tris‐(2‐pyridyl)‐s‐triazine as highly efficient sensitizers

“…and the data are given in Table . The decay profile is well reproduced by a single exponential ln( I ( t )/ I 0 ) = – k / t = – t /τ (where I 0 is the initial luminescence intensity and τ is the luminescence lifetime), indicating that all Eu 3+ ions occupy the same average coordination environment . In the europium complexes, the lifetime of Eu(TPTZ) 2 (NO 3 ) 3 (C 2 H 5 OH)·H 2 O (0.4156 ms) is the shortest and that of Eu 2 (TPTZ) 2 (C 8 H 4 O 4 )(NO 3 ) 4 (C 2 H 5 OH)·H 2 O (1.0486 ms) is the longest.…”

Synthesis, crystal structure, antibacterial activity and theoretical studies on a novel mononuclear cobalt(II) complex based on 2,4,6-tris(2-pyridyl)-1,3,5-triazine ligand

“…FTIR spectra of the samples were recorded on a FTIR JASCO 460 spectrophotometer using KBr pellet in the range of 4000-400 cm À1 and electronic spectra were obtained using a JASCO 7580 spectrophotometer. 1 (5) were prepared using the previously described procedures [20][21][22][23].…”

“…4(a and b), respectively. The FT-IR spectrum of free tptz displays three bands at 1617, 1524 and 1468 cm À1 due to the m(C@N) stretching mode of the triazine ring, and the m(C@C) and m(C@N) modes of the pyridyl rings, respectively [20]. The intense band at 1367 cm À1 is assigned to the stretching vibrations of both (1) 90.00(9) N(1)ACo(1)ACl (2) 88.69(10) N(4)ACo(1)ACl (2) 93.05(9) N(5)ACo(1)ACl (2) 89.14(10) O(1)ACo(1)ACl (2) 172.90(9) Cl(1)ACo(1)ACl (2) 96.82 (4) the triazine and pyridine rings of tptz.…”

“…The antibacterial potential of the newly synthesized cobalt complex together with a number of other tptz complexes of biologically important metal ions, such as nickel, copper, manganese, rhodium complexes with tptz were also studied [20][21][22][23]. These investigations screened the complexes for their antibacterial activities against both Gram positive and Gram negative bacteria [20][21][22][23][24].…”