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261.
The ligating properties 1-(2′-pyridylazo)-2-naphthol (HPAN) toward Rh(III) have been examined. The reaction of RhCl3·3H2O with HPAN in presence of excess PPh3 afforded trans-[Rh(PAN)Cl(PPh3)2]PF6 (3PF6). Intermediate cis-[Rh(PAN)Cl2(PPh3)] (4) has also been isolated. Solid state structures were authenticated by X-ray analyses revealing that monoanionic PAN is coordinated to rhodium in meridional fashion. Both the compounds were spectroscopically characterized in both solution and solid states, which include IR, NMR (1H and 31P), and optical spectra. The diamagnetic complexes show multiple CT transitions in the visible region. Low-energy transitions (λ ≈ 550–650 nm) occurred in the absorption spectra are predominantly ligand centered in nature. The rhodium(III)–PAN compounds are red emissive (λem ≈ 650 nm) at room temperature and the nature of the emission level is probably an ILCT level. Complexes are electro-active in acetonitrile and display irreversible oxidative and reductive waves and these responses are ascribed to be PAN ligand centered in character. 相似文献
262.
Abhishek Pramanik Dr. Samit Majumder Rampada Das Prof. Sasankasekhar Mohanta 《欧洲无机化学杂志》2023,26(22):e202300058
A fluorescent dinuclear cadmium(II) based discrete metal complex of composition [CdII2L(μ-Cl)Cl2]( 1 ) is used {HL=2,6-bis[2-(methylamino)ethyliminomethyl]-4-Ethylphenol} for the specific recognition of 2,4,6-trinitrophenol (picric acid; PA) via fluorescence quenching phenomenon among various nitroaromatic compounds through a chemodosimetric approach. It has been established that 1 is a chemodosimeter in pure water. We have successfully been able to isolate three compounds: chemodosimeter 1 ; an intermediate complex 2 of composition [CdII(LH2)Cl2](Picrate) and final association complex 3 of composition [NH3(CH2CH2)NH2CH3](Picrate)2. Compounds have been characterised by CHN elemental analyses, single crystal X-ray crystallography, PXRD, NMR and FTIR. Selective interaction of 1 with PA was evaluated by fluorescence, UV-Vis and life time measurements. Fluorescence quenching of 1 occurs definitely due to the formation of compound 3 via intermediate 2 involving partial decomplexation, hydrolysis and proton transfer phenomena in solution during the course of sensing. The quenching constant (Ksv), association constant (Ka) and detection limit (LOD) of the complex 1 for picric acid are ∼1.55×105 M−1, ∼1.8×1010 M−2 and ∼0.47 μM (0.108 ppm), respectively. Mechanism of sensing is proposed and the very rare case of isolation and characterization of intermediate in picric acid sensing is discussed. 相似文献