calix(4)arene and piperidine

The recognition of the mercury(II) ion (Hg(2+)) is essential because of its extreme toxicity in the environment and food. Hence we reported a novel cysteine (Cys) complex of piperidine-calix[4]arene (L) as a convenient and effective dual-signal responsive switch for Hg(2+). This switch system exhibited excellent selectivity toward Hg(2+) by fluorescence (FL), (1)H NMR spectroscopy and the atomic force microscopy (AFM). More importantly, the Hg(2+)-responsive switch had an important and potential application by water contact angle (CA) on a functional micro-nano silicon surface, including intelligent microfluidic and laboratory-on-chip devices, controllable drug delivery, and self-cleaning surfaces.

Topics: Calixarenes; Click Chemistry; Cysteine; Fluorescence; Magnetic Resonance Spectroscopy; Mercury; Models, Molecular; Molecular Structure; Particle Size; Phenols; Piperidines; Protons; Silicon; Surface Properties; Wettability

A piperidine-modified calix[4]arene derivative was synthesized and its structure was confirmed with X-ray diffraction data. UV-visible spectroscopy was used to study its molecular recognition of rare earth ions. The results revealed the calix[4]arene derivative could separate tight metal picrate ion pairs by complexation with the rare earth metal ions in tetrahydrofuran. Resolution of the UV-visible spectra with chemometric methods revealed that the derivative and the rare earth ions Eu(3+), Dy(3+), and Tb(3+) formed ML(2) complexes with stability constants of 10(8.26), 10(8.29), and 10(7.41) respectively.

Topics: Calixarenes; Coordination Complexes; Crystallography, X-Ray; Furans; Metals, Rare Earth; Models, Molecular; Phenols; Piperidines; Spectrophotometry, Ultraviolet