16280-66-3Relevant articles and documents
Structural, spectral and theoretical aspects in the coordination of a triazine-based ligand toward lead(II) with a holodirected environment
Marandi, Farzin,Moeini, Keyvan,Mostafazadeh, Bahman,Krautscheid, Harald
, p. 146 - 154 (2017)
Four complexes, [Cl(PPTA)2Pb(μ-Cl)2Pb(PPTA)2Cl] (1), [Br(PPTA)2Pb(μ-Br)2Pb(PPTA)2Br] (2), [I(PPTA)2Pb(μ-I)2Pb(PPTA)2I] (3) and [(PPTA)2Pb(NO3)2] (4), of 5-phenyl-3-(pyridin-2-yl)-1,2,4-triazine (PPTA) were prepared and identified by elemental analysis, FT-IR, 1H NMR spectroscopy and single-crystal X-ray diffraction. All the coordination modes of the 3-(pyridin-2-yl)-1,2,4-triazine-based ligands were studied by CSD software for predicting the behavior of the PPTA ligand in the reaction with metal ions. In the crystal structure of 1, the lead atom has a PbN4Cl3 environment with a distorted capped octahedral geometry. Complexes 2 and 3 are also dinuclear and isostructural with 1. The lead atom in the crystal structure of complex 4 has a coordination number of eight and a distorted cube geometry. The metal atom coordination spheres in all four structures tend to be holodirected with a decreasing deviation in the series 1–3. The thermodynamic stability of the isolated complexes and their charge distribution patterns were studied by DFT and NBO analysis. Theoretical studies reveal that the thermodynamic stability for the optimized complex 1 is more stable than those of the isostructural complexes 2 and 3.
Tandem oxidation processes for the regioselective preparation of 5-substituted and 6-substituted 1,2,4-triazines
Laphookhieo, Surat,Jones, Stuart,Raw, Steven A.,Sainz, Yolanda Fernández,Taylor, Richard J.K.
, p. 3865 - 3870 (2006)
α-Hydroxyketones undergo MnO2-mediated oxidation, followed by in situ trapping with 2-pyridylamidrazone, to give 3-pyridyl-5-substituted 1,2,4-triazines in a one-pot procedure, which avoids the need to isolate the reactive α-ketoaldehyde interm
Palladium(II)complexes of ambidentate and potentially cyclometalating 5-aryl-3-(2′-pyridyl)-1,2,4-triazine ligands
Zvirzdinaite, Maryte,Garbe, Simon,Arefyeva, Natalia,Krause, Maren,Von Der Stück, René,Klein, Axel
, p. 2011 - 2022 (2017/12/06)
The 5-aryl-3-(2′-pyridiyl)-1,2,4-triazine ligands under study [5-phenyl-(PyTZPh)L1 5-(3-methoxyphenyl)-(PyTZ3Me-OPh)L2 5-(4-methoxyphenyl)-(PyTZ4MeOPh)L3 5-(4-trifluoromethylphenyl)-(PyTZ4CF3Ph)L4 5-(4-fluorophenyl)-(PyTZ4FPh)L5 and tris-3,5,6-(2′-pyridyl)-1,2,4-triazine (Py3TZ)L6] react with [(COD)PdCl2] (COD = 1,5-cyclooctadiento form complexes [(L1-6)PdCl2] with N,N bidentate binding ligands, also including the potentially N,N,N tridentate ligand L6. This was concluded from an in-depth NMR spectroscopic study of the new complexes and from comparison with Pd-terpy complexes [(R′ terpy)PdCl]Cl [R′terpy = 4′-R′-2,2′:6′,2′′-terpyridine R′ = H or SMe], showing definite tridentate N,N,N coordination, and with the Pd-bpy complexes [(bpy)Pd(Mes)Cl] and [(bpy)PdCl2], show-ing definite bidentate N,N binding. The new ligands and complexes were fully characterised by multinuclear NMR spectroscopy, IR spectroscopy and mass spectrometry. No evidence for the parent triazine complexes is observed in EI-MS instead, cyclometalated complexes (HCl eliminatiowere detected in all cases. TDA/TG experiments support this assumption. Attempts to prepare the cyclometalated derivatives as substances failed, in line with the unfavourable binding mode. Detailed electrochemical measurements reveal ligand-centred reductions at very moderate potentials, in line with UV/Vis absorption spectroscopy and DFT calculations, revealing very low-lying triazine-centred LUMOs. Results from cyclic voltammetry also support the composition of [(Py3TZ)PdCl2].
