1452-63-7Relevant academic research and scientific papers
Comparative study of two new grid complexes: Synthesis, X-ray structure characterization, thermogravimetric, and spectroscopic properties
Wang, Yuan,Liu, Zheng,Wang, Yongliao,Gao, Jiongyang,Li, Yanhong
, p. 4357 - 4372 (2011)
The synthesis and characterization of two new grid complexes, [Ni 4(L)4(DMF)4]·2H2O (1) and [Mn4(L)4(DMF)4] (2) (where L is the anion of 3,5-dichlorosalicylaldehyde pyridine-2-formyl hydrazone), were investigated. X-ray crystal structure analysis reveals that the metal centers in both complexes exhibit slightly distorted square-bipyramidal coordination geometry. The dominating interaction of two adjacent grids for 1 and 2 is Cl...H hydrogen bonds. The halogen-hydrogen bond is a key factor to stabilize the crystal structure of chloro-substituted grid compounds. Thermogravimetric curves of 1 and 2 exhibit distinct weight loss stages at different temperatures and reflect the thermal stability of the complexes. Both UV-visible and fluorescence spectra of 1 and 2 indicate they have a stronger conjugated system and the same significant quenching ability compared with H2L. The ESI-MS spectra of 1 and 2 prove that the tetranuclear grids decompose in methanol/water solution.
A quinoline-based selective ‘turn on’ chemosensor for zinc(II) via quad-core complex, and its application in live cell imaging
Fu, Haoran,Liu, Haiyang,Zhao, Lei,Xiao, Boren,Fan, Tingting,Jiang, Yuyang
, (2019)
An efficient quinoline-based fluorescent chemosensor (QLNPY) was successfully developed for the detection of zinc ions (Zn2+). This novel chemosensor displayed higher sensitivity and selectivity toward Zn2+ over other competitive metal ions accompanying with obvious fluorescence enhancement. The QLNPY-Zn2+ complex can be further used as a new fluorescent “turn-off” sensor for pyrophosphate (PPi) and sulfur ion (S2?) via a Zn2+ displacement approach. The limits of detection were calculated to be 3.8 × 10?8 M for Zn2+, 3.7 × 10?7 M for PPi and 4.9 × 10?7 M for S2?. The binding mechanism of QLNPY and Zn2+ was investigated through NMR, HR-MS analysis and further studied by crystallographic analysis. Additionally, further application of QLNPY for sequential bioimaging of Zn2+ and PPi was studied in HepG2 cells, suggesting that the quinoline-based chemosensor possesses great potential applications for the detection of intracellular Zn2+ and PPi in vivo.
Application of a novel cationic iridium(iii) complex as a red phosphor in warm white light-emitting diodes
Meng, Guoyun,Chen, Zeyu,Tang, Huaijun,Liu, Yong,Wei, Liying,Wang, Zhengliang
, p. 9535 - 9542 (2015)
A novel red-emitting cationic iridium(iii) complex, [(Lm)2Ir(La)]PF6, (Lm: 2-(9-(2-ethylhexyl)-9H-carbazol-3-yl)benzo[d]thiazole, La: N,N-diphenyl-4-(5-(pyridin-2-yl)-1,3,4-oxadiazol-2-yl)aniline) was synthesized. Its ultraviolet-visible absorption and photoluminescent properties show that the complex can be efficiently excited by a 465 nm-emitting blue GaN chip, its decomposition temperature (Td) is 340 °C, and its relative emission intensity at 100 °C is 88.3% of 25 °C. Perfect red light with a CIE value of (0.65, 0.34) was obtained when it was used as a phosphor at 6.0 wt% blending concentration in epoxy resin in a blue GaN-based LED. A 465 nm-emitting blue GaN-based LED only using yellow-emitting Y3Al5O12:Ce3+ (YAG:Ce) as a phosphor (1.0 wt% in epoxy resin) emitted cold white, and its corresponding color rendering index (CRI) was 74.1, correlated color temperature (CCT) was 6026 K, and luminous efficiency (ηL) was 25.3 lm W-1. It became a neutral white light LED when the iridium(iii) complex was added at 0.5 wt%, the corresponding CRI was 79.5, CCT was 4004 K, and ηL was 32.6 lm W-1. It further became a warm white LED when the complex was blended at 1.0 wt% and 1.5 wt%, the corresponding CRI were 80.0 and 79.6, CCT were 3650 K and 3133 K, ηL were 25.5 lm W-1 and 22.8 lm W-1, and CIE values were (0.40, 0.39) and (0.43, 0.40), respectively. This complex is a promising red phosphor candidate for red LEDs and warm white LEDs.
Strong Equatorial Crystal Field Enhances the Axial Anisotropy and Energy Barrier for Spin Reversal Process in Yb2 Single Molecule Magnets
Mondal, Arpan,Konar, Sanjit
, p. 3449 - 3456 (2021)
The importance of equatorial crystal fields on magnetic anisotropy of ytterbium single molecule magnets (SMMs) is observed for the first time. Herein, we report three similar dinuclear ytterbium complexes with the formula [Yb2(3-OMe-L)2(DMF)2(NO3)2]?DMF (1), [Yb2(3-H-L)2(DMF)2(NO3)2]?DMF?H2O (2), and [Yb2(3-NO3-L)2(DMF)2(NO3)2] (3), [where 3-X-H2L=N′-(2-hydroxy-3-X-benzylidene)picolinohydrazide, X=OMe (1), H (2) NO2 (3)]. Detailed magnetic measurements reveal the presence of weak antiferromagnetic interactions between the Yb centers and a field-induced slow relaxation of magnetization in all complexes. A higher energy barrier for spin reversal was observed for complex 1 (Ueff=50 K) and it decreases in the order of 2 (47 K) to 3 (40 K). Notably, complex 1 shows a remarkable energy barrier within the frequency range of 1–850 Hz reported for Yb-based SMMs. Further, ab initio calculations show a higher axial anisotropy and lower quantum tunneling of magnetization (QTM) in the ground state for 1 compared to 2 and 3. It was also observed that the presence of a strong crystal field in the equatorial plane (when the ? O1?Yb?O3 bond angle is close to 90°) enhances the axial anisotropy and improves the SMM behavior in the studied complexes. Both the experimental and theoretical analysis of relaxation dynamics discloses that Raman and QTM play major role on slow relaxation process for all complexes. To provide more insight into the exchange interactions, broken-symmetry DFT calculations were performed.
An efficient colorimetric and absorption ratiometric anion sensor based on a simple azo-azomethine receptor
Li, Zheng,Wang, Shujun,Xiao, Liwei,Li, Xiaolong,Jing, Xuemin,Peng, Xiaoxia,Ren, Lilei
, p. 148 - 153 (2018)
An efficient colorimetric and absorption ratiometric azo-azomethine receptor N'-((E)-2-hydroxy-5-((E)-(4-nitrophenyl)diazenyl)benzylidene)picolinohydrazide (L) based on phenolic and acyl hydrazine binding units was synthesized and characterized by FT-IR, 1H NMR, 13C NMR and HRMS method. The optical response of L towards different anions was studied by colorimetric, UV–vis and 1H NMR titration method. The results revealed that L had a selective colorimetric sensing ability for biologically important F?, AcO? and H2PO4? by changing color from pale yellow to blue by naked-eye. Interestingly, the sensor L demonstrated an absorption ratiometric response towards F? (1:2 complex) and H2PO4? (1:1 complex) during the recognition process. The detection limit of the sensor L towards F?, AcO? and H2PO4? was estimated to be 2.94 μM, 4.12 μM and 12 μM respectively. The recognition mechanism was attributed to hydrogen bonding and subsequent deprotonation process according to 1H NMR titration experiments.
Synthesis and crystal structure of a novel pyridine acylhydrazone derivative as a “turn on” fluorescent probe for Al3+
Cai, Xinping,Huang, Ai,Huang, Jiaqi,Huang, Shoushun,Peng, Huanan,Peng, Xiaoming,Xu, Shujuan,Zhou, Jingjing
, (2020)
A novel acylhydrazone-based fluorescent probe HL was synthesized and characterized by 1H NMR, 13C NMR, mass spectrum (MS) and x-ray diffraction analysis. HL showed high selectivity and sensitivity towards Al3+ over other metal ions based on excited-state intramolecular proton transfer (ESIPT) and photo-induced electron transfer (PET) processes with a low detection limit (2.14 × 10?8 M) and reasonable pH application range (4.0–7.5). HL and Al3+ formed a 1:1 complex, leading to a remarkable fluorescence enhancement, which was confirmed by Job's plot experiments, 1H NMR and MS. Fluorescence titration experiments showed the fluorescence intensity of HL had good linearity with Al3+ concentration and can be used to detect Al3+ in real water samples.
Spectroscopic and theoretical studies on Cr (III), Mn (II) and Cu (II) complexes of hydrazone derived from picolinic hydrazide and O-vanillin and evaluation of biological potency
Abou-Melha, Khlood S.,Al-Hazmi, Gamil A. A.,Althagafi, Ismail,El-Gamil, Mohammed M.,El-Metwaly, Nashwa M.,Elghalban, Marwa G.,Shaaban, Fathy
, (2019)
Trivalent Cr (III) and divalent of both Mn (II) and Cu (II) complexes containing hydrazone ligands derived from the condensation of picolinohydrazide with O-vanillin were synthesised and characterized by elemental analysis, spectral and magnetic measurements. The suggested octahedral structures were confirmed by applying DFT optimization and conformational studies. The thermal decomposition behaviour of Mn (II) complex is discussed. The evaluation of kinetic parameters (Ea, A, ?H, ?S and ?G) of all thermal degradation stages have been evaluated using Coats-Redfern and Horowitz-Metzger approaches. The band gap results suggested that these complexes are semi-conductors and lie in same range of highly efficient photovoltaic materials. Antibacterial studies showed that higher activity of complexes than of ligands. Assay on the antioxidant activity (DPPH and SOD) of the above complexes revealed the high SOD-activity of Mn (II) complex and high DPPH-activity for ligand.
A novel turn-on fluorescent probe based on naphthalimide for the tracking of lysosomal Cu2+in living cells
Xu, Tingting,Huang, Junjie,Fang, Min,Sui, Mingshuai,Zhu, Yujing,Shentu, Yupeng,Li, Cun,Zhu, Weiju
, p. 21167 - 21175 (2020)
A novel fluorescent probe CuNI was synthesized and exhibited highly effective fluorescence detection ability for Cu2+ in aqueous solution (HOAc-NaOAc buffer, 10 mM, pH 5.0). CuNI was obtained by a simple condensation reaction between the aldehyde (MFNI, bearing the naphthalimide fluorescence group) and the 2-picolinyl hydrazide, which bears the Cu2+ recognized group. Under acidic conditions, CuNI showed turn-on fluorescence recognition of Cu2+ which could be readily distinguished with the naked eye under a 365 nm UV lamp and the detection limit is as low as 19.40 nM. It has been further demonstrated that CuNI was hydrolyzed under the action of Cu2+ and the significant increase of fluorescence is due to the obvious AIE effect of the hydrolysate MFNI. The application of the probe CuNI in imaging lysosomal Cu2+ in HepG2 cells has also been demonstrated. This journal is
A Highly Selective and Sensitive Fluorescent Probe Recognition for Co2+in Aqueous Media Based on 8-Hydroxyquinolin-2-carbaldehyde-2-pyridylformylhydrazone Derivative
Zhong, Keli,Zhao, Jie,Zhou, Xue,Hou, Shuhua,Bian, Yanjiang,Li, Jianrong,Tang, Lijun
, p. 1329 - 1334 (2016)
A new (8-hydroxyquinolin-2-yl)methylene picolinohydrazide derivative (L) has been successfully synthesized and characterized. The probe L displays high selectivity to Co2+in CH3CN/HEPES (1:1, Ｖ/Ｖ, 10 mmol·L?1, pH=7.4) with a fluorescence "ON-OFF" response. The Co2+ion recognition event possesses some distinct features including rapid response, high selectivity and sensitivity, good anti-interference ability and being applicable within a wide pH range. Based on job's plot and ESI-MS studies, the 1:1 binding mode was proposed. The binding constant of L and Co2+is 1.63×108L·mol?1and the detection limit is 1.15 μmol·L?1. Natural water samples experiments revealed that probe L can be potentially applied to the detection of Co2+in real environment.
The structural and magnetic properties of FeII and CoII complexes with 2-(furan-2-yl)-5-pyridin-2-yl-1,3,4-oxadiazole
Zoufaly, Pavel,?i?már, Erik,Kuchár, Juraj,Herchel, Radovan
, (2020)
Two novel coordination compounds containing heterocyclic bidentate N,N-donor ligand 2-(furan-2-yl)-5-(pyridin-2-yl)-1,3,4-oxadiazole (fpo) were synthesized. A general formula for compounds originating from perchlorates of iron, cobalt, and fpo can be written as: [M(fpo)2(H2O)2](ClO4)2 (M = Fe(II) for (1) Co(II) for (2)). The characterization of compounds was performed by general physico-chemical methods—elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) in case of organics, and single crystal X-ray diffraction (sXRD). Moreover, magneto-chemical properties were studied employing measurements in static field (DC) for 1 and X-band EPR (Electron paramagnetic resonance), direct current (DC), and alternating current (AC) magnetic measurements in case of 2. The analysis of DC magnetic properties revealed a high spin arrangement in 1, significant rhombicity for both complexes, and large magnetic anisotropy in 2 (D = ?21.2 cm-1). Moreover, 2 showed field-induced slow relaxation of the magnetization (Ueff = 65.3 K). EPR spectroscopy and ab initio calculations (CASSCF/NEVPT2) confirmed the presence of easy axis anisotropy and the importance of the second coordination sphere.
