Influence of Terminal Acryloyl Arms on the Coordination Chemistry of a Ditopic Pyrimidine-Hydrazone Ligand: Comparison of Pb(II), Zn(II), Cu(II), and Ag(I) Complexes
INORGANIC CHEMISTRY
Authors: Hutchinson, Daniel J.; Hanton, Lyall R.; Moratti, Stephen C.
Abstract
A new ditopic pyrimidine-hydrazone ligand, 6-hydroxymethylacryloyl-2-pyridinecarboxaldehyde, 2,2'-[2,2'-(2-methyl-4,6-pyrimidinediyl)bis(1-methylhydrazone)] (L2), was synthesized with terminal acryloyl functional groups to allow incorporation into copolymer gel actuators. NMR spectroscopy was used to show that L2 adopted a horseshoe shape with transoid-transoid pym-hyz-py linkages. Metal complexation studies were performed with L2 and salts of Pb(II), Zn(II), Cu(II), and Ag(I) ions in CH3CN in a variety of metal to ligand ratios. Reacting L2 with an excess amount of any of the metal ions resulted in linear complexes where the pym-hyz-py linkages were rotated to a cisoid-cisoid conformation. NMR spectroscopy showed that the acryloyl arms of L2 did not interact with the bound metal ions in solution. Seven of the linear complexes (1-7) were crystallized and analyzed by X-ray diffraction. Most of these complexes (4-7) also showed no coordination between the acryloyl arms and the metal ions; however, complexes 1-3 showed some interactions. Both of the acryloyl arms were coordinated to Pb(II) ions in [Pb2L2(SO3CF3)(4)] (1), one through the carbonyl oxygen donor and the other through the alkoxy oxygen donor. One of the acryloyl arms of [CuL2(CH3CN)(3)](SO3CF3), (2) was coordinated to one of the Cu(II) ions through the carbonyl oxygen donor. There appeared to be a weak association between the alkoxy donors of the acryloyl arms and the Pb(II) ions of [Pb2L2(ClO4)(4)]center dot CH3CN (3). Reaction of excess AgSO3CF3 with L2 was repeated in CD3NO2, resulting in crystals of {[Ag-7(L2)(2)(SO3CF3)(6)(H2O)(2)] SO3CF3L}(infinity) (8), the polymeric structure of which resulted from coordination between the carbonyl donors of the acryloyl arms and the Ag(I) ions. In all cases the coordination and steric effects of the acryloyl arms did not inhibit isomerization of the pym-hyz bonds of L2 or the core shape of the linear complexes.
A curcumin-based TPA four-branched copper(II) complex probe for in vivo early tumor detection
MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS
Authors: Pi, Zongxin; Wang, Jiafeng; Jiang, Bo; Cheng, Gang; Zhou, Shuangsheng
Abstract
A multibranched Cu(II) complex CuL2 curcumin-based was synthesized and characterized by single-crystal X-ray diffraction analysis. The photophysical properties of the complex have been investigated both experimentally and theoretically. The results show that the target complex exhibits higher quantum yield and larger two-photon absorption (TPA) cross-section in the near infrared (NIR) region compared with its free ligand. The cell imaging studies in vitro and in vivo reveal that the complex shows good photostability and excellent tumor targeting capability to tested cancerous cells, which can be potentially used for early tumor detection. (C) 2014 Elsevier B.V. All rights reserved.