calixarenes and pyrene

Calixarenes are considered as third generation supramolecules with hollow cavity-like architecture whereas nanoparticles are small entities with dimensions in the nanoscale. Many exciting achievements are seen when the calix system merges with nanoparticles which produces many fascinating facets in all fields of contemporary chemistry. The properties of nanoparticles which are tuned by calixarenes find applications in sensing, catalysis, molecular recognition, etc. Here, we have reviewed the chemistry of calix-based nanoparticles, and emphasis is laid on the modified, reducing, templated and stabilizing roles of calixarenes. This review covers the research being carried out in the domain of calix protected metal nanoparticles during last 18 years under the canopy of important 109 references. This article contains 58 figures which include 81 easy to understand structures. Calix-protected nanoparticles have enthralled researchers in the field of nanoscience with a tremendous growth in its applications, which heralds much promise to become in future a separate area of research.

Topics: Amino Acids; Calixarenes; Gold; Hydrocarbons; Metal Nanoparticles; Nanoparticles; Pesticides; Pyrenes; Silver; Surface-Active Agents

A fluorescent calix[4]arene triazole-linked pyrene (CP) was carefully designed and synthesized via click chemistry. The modification of CP with graphene oxide (GO) by a simple non-covalent interaction strategy is presented. Further inspection by electrochemical impedance spectroscopy reveals that the CP-GO could exhibit a very high supramolecular recognition for carbaryl, in particular in serum samples with a nanomolar concentration detection. Additionally, it is easy to directly observe macroscopic recognition by the contact angle, and expand practical applications.

Topics: Calixarenes; Carbaryl; Chemistry Techniques, Analytical; Click Chemistry; Fluorescent Dyes; Graphite; Models, Molecular; Molecular Conformation; Phenols; Pyrenes; Triazoles

A ratiometric fluorescent receptor with a C(3) symmetric structure based on a pyrene-linked triazole-modified homooxacalix[3]arene (L) was synthesized and characterized. This system exhibited an interesting ratiometric detection signal output for targeting cations and anions through switching the excimer emission of pyrene from the "on-off" to the "off-on" type in neutral solution. (1)H NMR titration results suggested that the Zn(2+) center of receptor L·Zn(2+) provided an excellent pathway of organizing anion binding groups for optimal host-guest interactions. It is thus believed that this receptor has potential application in sensing, detection, and recognition of both Zn(2+) and H(2)PO(4)(-) ions with different optical signals. In addition, the fluorescence emission changes by the inputs of Zn(2+) and H(2)PO(4)(-) ions can be viewed as a combinational R-S latch logic circuit at the molecular level.

Topics: Calixarenes; Fluorescent Dyes; Ions; Molecular Structure; Phosphoric Acids; Pyrenes; Stereoisomerism; Triazoles; Zinc

Topics: Calixarenes; Coated Vesicles; Coloring Agents; Macromolecular Substances; Molecular Structure; Pyrenes; Temperature

A novel calix[4]arene derivative locked in the 1,3-alternate conformation (2) bearing two pyrene and rhodamine fluorophores was synthesized as a selective sensor for the Hg(2+) ion. The sensoring is based on FRET from pyrene excimer emissions to ring-opened rhodamine absorption upon complexation of the Hg(2+) ion. Addition of Hg(2+) to a mixed solution of 2 gave significantly enhanced fluorescence at ∼576 nm via FRET with excitation at 343 nm. We also found that the pyrene excimer emissions formed by the intramolecular π-π interactions are more effective in obtaining strong FRET bands than those by intermolecular π-π interactions.

Topics: Calixarenes; Chemistry Techniques, Analytical; Dimerization; Fluorescence Resonance Energy Transfer; Mercury; Phenols; Pyrenes; Rhodamines; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet