Complexation of the N,N ',O-donor ligand N-trans-(2 '-hydroxycyclohexyl)-2-aminomethylpyridine

作者：Tiwow Vanny; Lawrance Geoffrey A^*; Maeder Marcel; Jensen Paul

来源：Journal of Coordination Chemistry, 2011, 64(20): 3637-3651.

DOI：10.1080/00958972.2011.628019

• Tridentate N,N ',O-donor ligand
• Substituted aminomethylpyridine
• Metal(II) complexation
• Formation constants
• X-ray crystal structures

The potentially tridentate N,N',O-donor N-trans-(2'-hydroxycyclohexyl)-2-aminomethylpyridine (1) forms ML(2) complexes with M(II) = Cu, Ni, and Zn. X-ray crystal structures of the isostructural Ni(II) and Zn(II) complexes confirm bis-tridentate coordination in significantly distorted octahedral geometries as the all-cis facial isomer. Structural comparisons with the previously reported all-trans facial Cu(II) and cis, cis, trans(N(py)) facial Co(III) complexes are presented. Protonation constants for 1 and stability constants with Cu(II), Ni(II), and Zn(II) are reported, with both ML and ML(2) species defined. The trend for ML (log K(1) values for Cu, Ni, and Zn of 8.3, 6.9, and 5.3, respectively) is conventional. Protonation and stability constants with Cu(II) for N, N-bis(2-pyridylmethyl) amine (2) were also defined. The log K(1) value measured for 2 of 7.4 is very similar to that found for 1 of 8.3, despite the marked difference in the third donor group; it appears that the third donor of the tridentate ligand generally binds only poorly to Jahn-Teller elongated Cu(II) in solution.

• 出版日期2011