228703-94-4Relevant academic research and scientific papers
Lanthanoid complexes supported by retro-Claisen condensation products of β-triketonates
Abad Galán, Laura,Sobolev, Alexandre N.,Zysman-Colman, Eli,Ogden, Mark I.,Massi, Massimiliano
, p. 17469 - 17478 (2019/01/03)
β-Triketonates have been recently used as chelating ligands for lanthanoid ions, presenting unique structures varying from polynuclear assemblies to polymers. In an effort to overcome low solubility of the complexes of tribenzoylmethane, four β-triketones with higher lipophilicity were synthesised. Complexation reactions were performed for each of these molecules using different alkaline bases in alcoholic media. X-ray diffraction studies suggested that the ligands were undergoing decomposition under the reaction conditions. This is proposed to be caused by in situ retro-Claisen condensation reactions, consistent with two examples that have been reported previously. The lability of the lanthanoid cations in the presence of a varying set of potential ligands gave rise to structures where one, two, or three of the molecules involved in the retro-Claisen condensation reaction were linked to the lanthanoid centres. These results, along with measurements of ligand decomposition in the presence of base alone, suggest the solvent used will modulate the impact of the retro-Claisen condensation in these complexes.
Discotic Liquid Crystals of Transition Metal Complexes, 2: The Effect of Alkyl Chain Length on Discotic Mesomorphism in Biscopper(II)
Ohta, Kazuchika,Muroki, Hiromitsu,Takagi, Akira,Yamamoto, Iwao,Matszaki, Kei
, p. 247 - 264 (2007/10/02)
A Series of disk-like complexes, biscopper(II) (n-alkyl: R=CnH2n+1 n=0-12; Cn-Cu(II)), have been synthesized in focusing our interest on the effect of the alkyl chain length for the discotic mesomorphism.It was found that each of the copper(II) complexes substituted by R=C4H9-C12H25 is a discogen, and that each of the complexes from C7-Cu(II) to C9-Cu(II) has plural discotic mesophases.C9-Cu(II) has three discotic mesophases which is the first example in transition metal complexes.Each of the complexes, Cn-Cu(II) (n=5-7, 9-11), has two solid polymorphs with different m.p.s in monotropic relationship.Each of the ligands substituted by R=C7H15- C12H25 (C7-Ligand - C12-Ligand) is a smectogen.It became to be clear that the discotic mesogen complexes can be obtained even when the non-mesomorphic ligands (n=4-6) are used.Keywords: discotic mesophase, bis(β-diketonato)copper(II) complexes, alkyl chain length effect
