Catenated Nitrogen Ligands Part II. Transition Metal Derivatives of Triazoles, Tetrazoles, Pentazoles, and Hexazine

Synthesis, characterization and low temperature self assembling of (η3-allyl)palladium complexes with 2-pyridyl-1,2,3-triazole bidentate ligands. Study of the catalytic activity in Suzuki–Miyaura reaction

“…2 for the relevant numbering scheme). In fact, in the 1 H NMR (acetone-d 6 , r.t.) spectrum both the characteristic doublet due to H(11) and the singlet due to H(2) are shifted downfield with respect to the free ligand (d coord À d free ¼ 0.48 ppm and 0.60 ppm, respectively), as previously found for complex 1. Chelation of the ligand is also supported by the 13 C NMR data in which both C(11) and C(2) resonate at lower fields with respect to free L2; the Dds are 5.8 and 3.8 ppm, respectively, values very close to those observed in the case of complex 1.…”

“…Chelation of the ligand is also supported by the 13 C NMR data in which both C(11) and C(2) resonate at lower fields with respect to free L2; the Dds are 5.8 and 3.8 ppm, respectively, values very close to those observed in the case of complex 1. In keeping, the r.t. 1 H NMR spectrum of 2 (acetone-d 6 ) confirms that the allyl moiety is coordinated to palladium in a trihapto mode, in fact, the allyl protons give rise to a sharp multiplet centered at 6.17 d (central proton H(13)) accompanied by a slightly broad doublet (4.51 d, J ¼ 6.5 Hz) attributable to the anti protons and a much broader doublet centered at 3.73 d (J ¼ 12.4 Hz) due to syn protons.…”

“…Unexpected facets of the behavior in solution of 2 emerge when its 1 H NMR spectrum is registered in acetone-d 6 lower than 223 K, as below this temperature several new resonances grow up nearby the signals due to 2. The overall proton spectrum becomes very intricate since the new resonances partially overlap those of 2, however inspection of the spectral region where the pyridine ortho-hydrogen signals occur reveals that the new resonances are sharp and strongly resemble in shape those of 2 (Fig.…”

Synthesis, crystal structure, solution behavior and catalytic activity of a palladium(II)-allyl complex containing a 2-pyridyl-1,2,3-triazole bidentate ligand

“…In fact, different studies have shown that 1,2,3-triazoles are able to coordinate a metal center through N (2) or N(3) [6,7] or, but rarely, through C(5) [8].…”

Synthesis and Evaluation of Bombesin Analogues Conjugated to Two Different Triazolyl‐Derived Chelators for 99mTc Labeling

“…[35,36] The resulting triazole ring is known to be a good ligand for various transition metals. [37] We evaluated the synthesis of these triazole-based chelators and their capacity for labeling with the 99m Tc(CO) 3 core. The biodistribution of these triazolecontaining bombesin analogues was compared with the corresponding (N a His)Ac analogues.…”