RESUMO
Here, we report a design strategy for constructing supramolecular organic frameworks by introducing 1H-pyrazole groups to aromatic cores as non-coplanar molecules to form diverse supramolecular assemblies through multiple 1H-pyrazole [N-H···N] hydrogen bonds as well as other weak interactions. The new supramolecular organic frameworks displayed interesting crystallization-induced emission (CIE) behavior.
Assuntos
Pirazóis , Cristalização , Ligação de Hidrogênio , Pirazóis/químicaRESUMO
Luminescent organic molecules are of important realistic significance to the human health and ecological environment due to their fascinating applications. Here we report the design and synthesis of luminescent organic-molecules by introducing two or four NH-pyrazolate groups as mercury-binding moieties to aromatic cores. Interestingly, the new aromatic tetraphenylene-bridged multi-NH-pyrazoles exhibit strong fluorescence in both aggregate and solid state and constitutes highly selective proof-of-concept luminescent sensor for Hg(II) ion among various competitive transition-metal ions in both organic and mixed solutions via metal-nitrogen binding. Especially, the present sensor including two NH-pyrazolyl groups showed an extremely high sensitivity with low limit of detection of 7.26 and 3.67 nM. The proposed design strategy provides a wide scope for the construction of unique turn-on sensors with substantial potential in the sense of heavy metal pollution in enviromental water samples.
Assuntos
Mercúrio , Metais Pesados , Corantes Fluorescentes/química , Humanos , Íons , Espectrometria de FluorescênciaRESUMO
The study on the in-situ FTIR spectroelectrochemistry of a hybrid copper-cobalt hexacyanoferrate film modified platinum electrode was carried out. The variation of the FTIR spectra was well correlated to the redox process of CuCoHCF. The relative contribution of Cu(II) and Co(II) to the stretching vibration of CN was found to vary with the applied potential.
Assuntos
Cobalto/química , Cobre/química , Eletrodos , Ferrocianetos/química , Eletroquímica , Oxirredução , Platina , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Comparative studies were carried out by using electrochemistry and in-situ FTIR spectroelectrochemistry for nonlinear optical complexes, S-benzyl-N-(ferrocenyl-1-methyl-metylidene)-dithiocarbazate nickel (II)/cobalt (II) complexes (Ni(LSB)2/Co (LSB)2). The results indicated that Ni(LSB)2 involves two consecutive reversible one-electron oxidation steps, while Co(LSB)2 involves only one two-electron oxidation step. Ni(LSB)2 complex that has a square planar configuration exhibits a moderately strong electronic communication between the two-ferrocene moieties, taking place through the skeleton chain of the ligand due to the extensive electron delocalization in the whole molecule and leads to the appearance of a strong nu c-c vibration band at 1,453 cm-1 during the oxidation process, while Co(LSB)2 complex that has a tetrahedral configuration shows low electron delocalization and has two almost identical ferrocene moieties.