Off–on–off pH luminescence switching and DNA binding properties of a free terpyridine-appended ruthenium complex

Zheng, Ze-Bao; Kang, Si-Yuan; Yi, Xun; Zhang, Na; Wang, Kezhi

doi:10.1016/j.jinorgbio.2014.08.010

Cited by 23 publications

(19 citation statements)

References 59 publications

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“…The steadystate emission spectra were recorded on an Edinburgh FLS920 time-resolved fluorescence spectrometer at 298 K in H 2 O, using a 1 cm path length quartz cell. Time-correlated single-photoncounting (TCSPC) measurements were used for the luminescence decay of the ruthenium complex at different pHs (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). The luminescence quantum yields (j) were calculated by employing eqn (1), 15,16 using [Ru(bpy) 3 (PF 6 ) 2 ] as the standard.…”

Section: Spectroscopic Analysesmentioning

confidence: 99%

“…We also conducted a luminescence experiment to determine the behaviour of the emission of the complex in water at various pHs (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). Fig.…”

Section: Experiments On Absorption and Luminescence Spectroscopymentioning

confidence: 99%

“…3 Protonation or deprotonation of basic or acidic sites in metal complexes, respectively, exhibits a dependence on the pH of the medium. The presence of amino, 7 carboxylic, 8 hydroxyl 9 or imidazole-functionalized ligands 10 acting as protonatable and deprotonatable moieties in the Ru(II) complexes could regulate the photophysical properties effectively for a pH-responsive on-off switch, and therefore would be useful in the design of a pH sensor. At the equilibrium point, the protonated and deprotonated forms of the Ru(II) complex exhibit variations in their emission and/or absorption spectra, and the pH of the medium may affect the ground state or the excited state species.…”

Section: Introductionmentioning

confidence: 99%

“…For the sake of comparison, we calculated the on-off ratio of the reported complexes in a water solution only. The first study 13 of complex [(dip) 2 Ru-mopip] 2+ (dip = 4,7-diphenyl-1,10-phenanthroline and mopip = 2-phenyl-OCH 3 -imidazo [4,5-f ] [1,10]phenanthroline) [ Fig. 1(a)] revealed an on-off factor of 2.33 at 500 nm in the absorption spectra.…”

Section: Introductionmentioning

confidence: 99%

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Augmented pH-sensitivity absorbance of a ruthenium(ii) bis(bipyridine) complex with elongation of the conjugated ligands: an experimental and theoretical investigation

Tan

Yanagisawa

Inagaki

et al. 2017

Phys. Chem. Chem. Phys.

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An absorbance-based sensor employing ruthenium bipyridyl with a phenanthroline-fused benzoylthiourea moiety formulated as [Ru(ii)(bpy)(phen-nBT)](PF) {bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, nBT = n-benzoylthiourea} has been synthesized and characterized by elemental analyses, mass spectrometry, and infrared, ultraviolet-visible, luminescence and nuclear magnetic resonance spectroscopy. The changes in the intensity of absorption and emission of the complex induced by functionalization of the benzoylthiourea ligands with amino and carbonyl in their protonated and deprotonated forms were studied experimentally. The absorption and emission properties of the complex exhibit a strong dependence on the pH (1-11) of the aqueous medium. This work highlights the pH-sensitivity augmentation of the absorption band by elongating the conjugation length in the structure of the ruthenium bipyridine complex. The principle of this work was to design the title compound to be capable of enhancing the differences in the absorption sensitivity responses towards pH between the protonated and deprotonated complexes in the absorption measurement. Along with significant and noticeable changes in the absorption spectra, subsequent theoretical investigations specifically on the electronic and absorbance properties of the title compound were carried out in this study. Protonation of the molecule significantly stabilized the lowest-unoccupied molecular orbital (LUMO), whereas the highest-occupied molecular orbital (HOMO) is greatly destabilized upon deprotonation. A time-dependent density functional theory (TDDFT) calculation in the linear-response (-LR) regime was performed to clarify the origin of the experimentally observed linear dependence of absorption intensity upon pH (1-11). The MLCT band exhibits hyperchromic shift at low pH as indicated by the large transition dipole moment and a wider distribution of the response charge of the molecule, which is induced by the stabilization of the electrostatic potential at the carbonyl moiety by protonation. This study provides the possibility of employing theoretical information to gain insight into the origin of the optical absorption obtained experimentally. The ruthenium complex was designed with an elongated ligand conjugation length and exhibited a tremendously large change in the absorption intensity of the protonated and deprotonated forms, which therefore demonstrates its feasibility as an indicator molecule especially for absorbance measurements.

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Section: Spectroscopic Analysesmentioning

confidence: 99%

“…We also conducted a luminescence experiment to determine the behaviour of the emission of the complex in water at various pHs (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). Fig.…”

Section: Experiments On Absorption and Luminescence Spectroscopymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Augmented pH-sensitivity absorbance of a ruthenium(ii) bis(bipyridine) complex with elongation of the conjugated ligands: an experimental and theoretical investigation

Tan

Yanagisawa

Inagaki

et al. 2017

Phys. Chem. Chem. Phys.

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“…However, only limited numbers of papers concerning 2,6-di(2-pyrazinyl)pyridine that is analogous to terpyridine have so far appeared in the literature [24][25][26], and its homoleptic Ru II complexes showed longer excited state lifetime and much more useful photosensitization than its terpyridyl Ru(II) analogs [27][28][29][30][31][32]. The Ru(II) polypyridyl complexes containing imidazole and/or free metal ion binding sites have received growing attention as optical sensors for pH [16][17][18][33][34][35][36] or Cu 2+ [37][38][39][40][41]. However, but much work is needed to improve sensing sensitivity and selectivity.…”

Section: Introductionmentioning

confidence: 99%

pH and copper ion luminescence on/off sensing by a dipyrazinylpyridine-appended ruthenium complex

Zheng

Kang

Zhao

et al. 2015

Sensors and Actuators B: Chemical

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Synthesis, Structural and Biological Studies of Some Half‐Sandwich d⁶‐Metal Complexes with Pyrimidine‐Based Ligands

et al. 2017

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The reaction of metal precursors {[Cp*MCl2]2 (M=Rh, Ir)} with 2‐aminopyrimidine (L1) gave binuclear complexes as [(Cp*MCl2)2(μ‐L1)], where L1 acted as a bridging ligand. While 2‐mercaptopyrimidine (L2) with [Cp*MCl2]2 {M=Rh(III), Ir(III)} formed mononuclear di substituted complexes as [Cp*M(L2)2], where L2 acted as a chelating as well as a monodentate ligand. The reaction of [CpRu(PPh3)2Cl] with 2‐mercaptopyrimidine (L2) led to the formation of mononuclear complex as general formula [CpRu(PPh3)(L2)] in presence of a base. 2‐Mercaptopyrimidine ligand resulted complexes with strained four‐membered metallacycle while 2‐aminopyrimidine yielded bridged complexes. HOMO‐LUMO energy gaps and UV‐Visible bands were additionally rationalised by the DFT studies. The binding ability of the complexes to the CT‐DNA was confirmed using UV‐Visible and fluorescence spectroscopy. In vitro antibacterial activity of the complexes was evaluated against human pathogenic bacteria. Cytotoxicity of the complexes was examined by the MTT assay over three cancerous and one non‐cancer cell lines viz., BE, HT‐29, MIA−Pa‐Ca2 and ARPE‐19.

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Off–on–off pH luminescence switching and DNA binding properties of a free terpyridine-appended ruthenium complex

Cited by 23 publications

References 59 publications

Augmented pH-sensitivity absorbance of a ruthenium(ii) bis(bipyridine) complex with elongation of the conjugated ligands: an experimental and theoretical investigation

Augmented pH-sensitivity absorbance of a ruthenium(ii) bis(bipyridine) complex with elongation of the conjugated ligands: an experimental and theoretical investigation

pH and copper ion luminescence on/off sensing by a dipyrazinylpyridine-appended ruthenium complex

Synthesis, Structural and Biological Studies of Some Half‐Sandwich d⁶‐Metal Complexes with Pyrimidine‐Based Ligands

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Off–on–off pH luminescence switching and DNA binding properties of a free terpyridine-appended ruthenium complex

Cited by 23 publications

References 59 publications

Augmented pH-sensitivity absorbance of a ruthenium(ii) bis(bipyridine) complex with elongation of the conjugated ligands: an experimental and theoretical investigation

Augmented pH-sensitivity absorbance of a ruthenium(ii) bis(bipyridine) complex with elongation of the conjugated ligands: an experimental and theoretical investigation

pH and copper ion luminescence on/off sensing by a dipyrazinylpyridine-appended ruthenium complex

Synthesis, Structural and Biological Studies of Some Half‐Sandwich d6‐Metal Complexes with Pyrimidine‐Based Ligands

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Synthesis, Structural and Biological Studies of Some Half‐Sandwich d⁶‐Metal Complexes with Pyrimidine‐Based Ligands