824424-71-7Relevant articles and documents
Ether based flexible bis Schiff base fluorescent colorimetric chemosensors for selective and sensitive detection of HF2 ? ion
Chandra, Rukmani,Sahu, Meman,Manna, Amit Kumar,Rout, Kalyani,Chowdhury, Shubhamoy,Patra, Goutam K.
, (2020)
Two simple and low cost bis Schiff base fluorescent colorimetric chemosensors L1 and L2 have been designed and synthesized. These sensors could detect important anion HF2 ? by change in both absorption and fluorescence intensity in methanol tris HCl buffer (1:1 v/v) solution at physiological pH. The mechanism of selectivity and sensitivity of these receptors to HF2 ? has proposed to be on the basis of photo-induced electron transfer (PET), chelation enhanced fluoresence (CHEF) and hydrogen bonding mechanism, confirmed by FT-IR, 1H-NMR and ESI-mass spectra. Interestingly, chelation of HF2 ? to the receptors takes place in 1:2 ratio, which has been confirmed by job plots analysis, ESI-mass spectra, DFT and TD-DFT studies. The detection limits of the probes L1 and L2 for HF2 ? were determined to be 6.1 μM for L1 and 3.94 μM for L2 respectively, on the basis of 3σ/K. Importantly, the low detection limits of L1 and L2 for HF2 ?suggest that L1 and L2 are sensitive sensors for detection of these ions in drinking water. The receptors L1 and L2 can successfully applied for detection and quantification of HF2 ? in real samples. To the best of our knowledge this is the third report of fluorescent colorimetric chemosensors for HF2 ? ions.
Magnetic and luminescent binuclear double-stranded helicates
Cucos, Paula,Tuna, Floriana,Sorace, Lorenzo,Matei, Iulia,Maxim, Catalin,Shova, Sergiu,Gheorghe, Ruxandra,Caneschi, Andrea,Hillebrand, Mihaela,Andruh, Marius
, p. 7738 - 7747 (2014)
Three new binuclear helicates, [M2L2]·3DMF (M = Co(II), 1, Zn(II), 3) and [Cu2L2]·DMF·0. 4H2O (2), have been assembled using the helicand H2L that results from the 2:1 condensation reaction between o-vanillin and 4,4′-diaminodiphenyl ether. The metal ions within the binuclear helicates are tetracoordinated with a distorted tetrahedral geometry. Direct current magnetic characterization and EPR spectroscopy of the Co(II) derivative point to an easy axis type anisotropy for both Co(II) centers, with a separation of at least 55 K between the two doublets. Dynamic susceptibility measurements evidence slow relaxation of the magnetization in an applied dc field. Since the distance between the cobalt ions is quite large (11.59 A), this is attributed in a first instance to the intrinsic properties of each Co(II) center (single-ion magnet behavior). However, the temperature dependence of the relaxation rate and the absence of slow dynamics in the Zn(II)-doped sample suggest that neither the simple Orbach mechanism nor Raman or direct processes can account for the relaxation, and collective phenomena have to be invoked for the observed behavior. Finally, due to the rigidization of the two organic ligands upon coordination, the pure zinc derivative exhibits fluorescence emission in solution, which was analyzed in terms of fluorescence quantum yields and lifetimes.
Dinuclear Pd(II) complexes containing bis-O,N-bidentate Schiff base ligands: Synthesis, characterization, DFT study and application as Suzuki–Miyaura coupling catalysts
Nandhini, Raja,Venkatachalam, Galmari,Deepan Kumar, Madhu,Jaccob, Madhavan
, p. 183 - 192 (2018/11/23)
The reaction of binucleating Schiff base ligands with [PdCl2(PPh3)2] and [Pd(OAc)2] afforded a new family of binuclear palladium(II) Schiff base complexes of the type [Pd2(L)2] and [Pd2Cl2(PPh3)2(L)]. All the palladium complexes are air stable and fully characterized by elemental analysis, FT-IR, UV–Vis and 1H NMR spectral methods. These palladium(II) Schiff base complexes exhibit characteristic metal to ligand charge transfer (MLCT) transitions. Quantum mechanical calculations were also performed to investigate the electronic structure, assign the vibrational spectra and to determine the nature of the frontier molecular orbitals and absorption spectra of the above complexes. These palladium(II) Schiff base complexes exhibited good catalytic activity in the carbon–carbon Suzuki coupling reaction of different aryl halides using phenyl boronic acid.
