Ruthenium(II)‐Polypyridyl‐Based Sensor Bearing a DPA Unit for Selective Detection of Cu(II) Ion in Aqueous Medium

Abstract

Ruthenium(II) polypyridyl linked di‐(2‐picolyl)amine (DPA) based chemosensor [Ru(bpy)2(bpmpip)](PF6)2 (Ru‐L) has been developed for the selective detection of Cu(II) ion in purely aqueous medium. The change in absorbance and emission spectra of chemosensor Ru‐L was observable upon addition of Cu2+ ion. Competitive binding studies, detection limit (18.9 nM) and binding constants illustrate significant sensing ability of chemosensor Ru‐L. Spectral behaviour of chemosensor Ru‐L at different pH was also investigated in absence and presence of Cu2+ ion. Binding of Cu2+ to Ru‐L occurs in 1:1 stoichiometry, in good agreement with the results obatined from ESI‐mass spectrometry, Job's plot experiment and spectroscopic titrations. The emission intensity of Ru‐L was selectively quenched by Cu2+ ion and an obvious color change from red orange to yellow in aqueous solution as well as on paper strips was observed under UV light. The reversibility cycles for the detection of Cu2+ ion were achieved by EDTA and corresponding logic gate was also developed. The water solubility, reversibility and optical visualization of the present chemosensor make it ideal for practical applications on real samples.

Bioinspired Heterobimetallic Photocatalyst (RuIIchrom−FeIIIcat) for Visible-Light-Driven C–H Oxidation of Organic Substrates via Dioxygen Activation

“…Both Ru II and Fe III adopt a pseudooctahedral geometry. All of the bond parameters concerning the metal cores in Ru II chrom –Fe III cat (Tables S1 and S2) are consistent with the data reported earlier for the Fe , and Ru , analogues. Notably, the relatively short distance between Ru and Fe (8.328 Å) may promote a facile electron tunneling between the redox partners. , …”

“…A singlet at 14.01 ppm was assigned to −NH− group of the imidazole ring in a free ligand. 50 Two singlets near 3.89 and 4.05 ppm were assigned to the −CH 2 −pyridine moieties of TPA unit. Furthermore, the electrospray ionization mass spectrometry (ESI-MS) study for Ru II chrom yielded an exact mass of 1213.1915 corresponding to a protonated molecular ion [M + H] + coinciding well with the theoretical value of 1213.1904 (Figure S7).…”

“…The 1 H NMR spectra of Himptp and Ru II chrom clearly revealed all of the expected resonances (Figures S3 and S4). A singlet at 14.01 ppm was assigned to −NH– group of the imidazole ring in a free ligand . Two singlets near 3.89 and 4.05 ppm were assigned to the −CH 2 –pyridine moieties of TPA unit.…”

Turn-on detection of Al3+ and Zn2+ ions by a NSN donor probe: reversibility, logic gates and DFT calculations

“…The value of K b may be determined using the slope of the straight line obtained from the plot of 1/( F − F 0 ) against 1/[M n + ]. 79,80…”

“…The value of K b may be determined using the slope of the straight line obtained from the plot of 1/(F − F 0 ) against 1/[M n+ ]. 79,80 Job's plot A series of CH 3 CN-H 2 O solutions (4 : 1, v/v) containing NpSb and M n+ (Al 3+ or Zn 2+ ) were prepared and the absolute concentration of NpSb was kept as 1.3 × 10 −6 M. The mole fraction was then varied from 0 to 1.0. A graph of the emission response of NpSb was plotted between (F − F 0 ) × (1 − X) and the mole fraction (X) of the M n+ ion.…”