The multicomponent Castagnoli‐Cushman reaction followed by post‐condensational modifications allowed for a flexible, modular construction of fluorescent chemosensor compounds. When tested against a panel of fourteen metal ions, one of the eight compounds investigated in this work was found to selectively respond to Cu2+ ions by fluorescence quenching (thus being a “turn‐off” chemosensor for this metal). Another compound was found to produce fluorescence increase in response to Pb2+ ions. Interestingly, the sensitivity of this “turn‐on” chemosensor to lead(II) ions was unaffected by the presence of a large excess of other metals. Analysis of the structure‐sensing property relationships of these sensors allowed developing a general understanding of the factors influencing the chemosensor properties. All of the critical structural factors employed in the chemosensor design were found to be important for the metal sensing and selectivity. These findings will allow designing next‐generation chemosensors based on the same modular construction approach in the future.
Self-healing materials are an essential emerging class
of smart
materials, capable of repairing their damage after external stimuli,
especially mechanical damages. However, the lack of studies on self-healing
polymers after electrical breakdown is highly important for electrical
engineering and electronics. We propose to use a nickel(II)-2,6-pyridinedicarboxamide-co-polydimethylsiloxane complex (NiPyPDMS) as an electrical
breakdown protective material. To provide the absence of dust deposition
from ambient air and to increase durability, we fabricated multilayered
polymer “sandwiches” consisting of a NiPyPDMS layer
covered with two films (polypropylene (PP) or polydimethylsiloxane
(PDMS)) on both sides. Multilayered PP-NiPyPDMS-PP and PDMS-NiPyPDMS-PDMS
films exhibit autonomous self-healing properties (up to 75%) after
electrical breakdown at room temperature. NiPyPDMS demonstrates 3.7
times higher adhesion to copper, from which power lines are made,
compared to PDMS. NiPyPDMS also exhibits antistatic and redox properties
(NiII/NiIII transformations when electricity
is applied). All characteristics mentioned above lead to reduce the
probability of electrical breakdown via electrical
charge dissipation in self-healing coating on possible power lines.
Photoluminescent lanthanide complexes of Eu3+ and Tb3+ as central atoms and N6,N6’-diisopropyl-[2,2′-bipyridine]-6,6′-dicarboxamide as ligand were synthesized. The structure of these complexes was established by single-crystal X-ray diffraction, mass spectrometry, 1H and 13C nuclear magnetic resonance, ultraviolet-visible, infrared spectroscopy, and thermogravimetry. Bipyridinic ligands provide formation of coordinatively saturated complexes of lanthanide ions and strong photoluminescence (PL). The Eu3+- and Tb3+-complexes exhibit PL emission in the red and green regions observed at a 340 nm excitation. The quantum yield for the complexes was revealed to be 36.5 and 12.6% for Tb3+- and Eu3+-complexes, respectively. These lanthanide compounds could be employed as photoluminescent solid-state compounds and as emitting fillers in polymer (for example, polyethylene glycol) photoluminescent materials.
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