1452-63-7Relevant articles and documents
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.
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.
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.
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 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.
Linear-shaped Ln III 4 and Ln III 6 clusters constructed by a polydentate Schiff base ligand and a β-diketone co-ligand: structures, fluorescence properties, magnetic refrigeration and single-molecule magnet behavior
Wang, Wen-Min,He, Li-Yuan,Wang, Xin-Xin,Shi, Ying,Wu, Zhi-Lei,Cui, Jian-Zhong
, p. 16744 - 16755 (2019)
Herein, ten new linear-shaped LnIII4 and LnIII6 clusters, with the formula [Ln4(acac)6L2(CH3O)2(CH3OH)4]·xCH3OH (Ln = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Dy (6), and Tm (8), Hacac = acetylacetone), [Ln6(acac)4L4(CH3O)6]·xCH3OH (Er (7) and Yb (9)), and [Lu4(acac)6L2(OH)2]·2CH2Cl2 (10), based on a polydentate Schiff base ligand, H2L, and a β-diketone co-ligand were successfully synthesized and structurally characterized. Single crystal X-ray diffraction measurements reveal that the structures of the clusters 1-6, 8 and 10 are very similar and their central Ln(iii) ions are linearly arranged Ln4; however, the clusters 7 and 9 possess a rare linearly arranged Ln6. The investigations on the solid-state fluorescence properties show that the clusters 2, 3, 5 and 6 display the characteristic lanthanum luminescence at room temperature. Magnetic studies reveal that weak antiferromagnetic interactions exist between adjacent Gd(iii) ions in cluster 4. More importantly, the cluster 4 exhibits significant MCE with the maximum -ΔSm value of 27.96 J kg-1 K-1 at 2.0 K and 7.0 T, whereas the cluster 6 displays a slow magnetic relaxation behavior under a zero dc field with the effective energy barrier ΔE/kB = 8.64 K and τ0 = 6.98 × 10-6 s.
A simple Schiff base as dual-responsive fluorescent sensor for bioimaging recognition of Zn2+ and Al3+ in living cells
Liu, Haiyang,Liu, Tianqi,Li, Jia,Zhang, Youming,Li, Jiahua,Song, Jun,Qu, Junle,Wong, Wai-Yeung
, p. 5435 - 5442 (2018)
A simple Schiff base fluorescent sensor (BDNOL) was synthesized from the reaction of picolinohydrazide and 4-(diethylamino)salicylaldehyde, and developed for selective detection of Al3+ and Zn2+. This non-fluorescent sensor displayed obvious fluorescence enhancement after binding to Al3+/Zn2+ ions with high sensitivity and selectivity, accompanied by obvious fluorescence emission enhancement (504 nm for Al3+ and 575 nm for Zn2+). The detection limits were found to be 8.30 × 10-8 M for Al3+ and 1.24 × 10-7 M for Zn2+. The binding mechanisms between BDNOL and Al3+/Zn2+ ions were supported by 1H NMR and HR-MS analysis, and a density functional theory (DFT) study. The sensing behavior was also studied with molecular logic functions of OR, AND, and NOT gates. Furthermore, the fluorescent sensor was successfully used to recognize Al3+ and Zn2+ in living cells, suggesting that this simple biosensor has great potential in biological imaging applications.
Cis and Trans Isomers of Fe(II) and Co(II) Complexes with Oxadiazole Derivatives - Structural and Magnetic Properties
Zoufaly, Pavel,Kliuikov, Andrii,?i?már, Erik,Císa?ová, Ivana,Herchel, Radovan
, p. 1190 - 1199 (2021)
Four complexes with bidentate N,N-donors 2-(furan-2-yl)-5-(pyridin-2-yl)-1,3,4-oxadiazole (fpo) and 2-(pyridin-2-yl)-5-(thiophen-2-yl)-1,3,4-oxadiazole (pto) with general formula [M(L)2(NCS)2] (M=Co(II), L=fpo for (1); M=Co(II), L=pto for (2); M=Fe(II), L=fpo (3); M=Fe(II), L=pto (4)) are reported. Analysis and characterization of the samples was performed using standard physico-chemical techniques – elemental analysis, nuclear magnetic resonance, Fourier transform infrared spectroscopy, single-crystal X-ray diffraction. Magnetic properties for 1–4 revealed large magnetic anisotropy of Co(II) complexes, and AC susceptibility measurements confirmed their single-molecule magnetic behaviour. Furthermore, the theoretical calculations at DFT and CASSCF/NEVPT2 level of theory were exploited to better understand magnetism of these compounds.
Synthesis of pyridine-2-aldoxime-C-14 methiodide (2-PAM-C-14 iodide).
CLARK,ROTH
, p. 96 - 97 (1963)
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Synthesis and Characterization of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with 2-Carboxy benzaldehyde Aroylhydrazones
Al-Daher, Abdul Ghany M.,Alfares, Amenah A.,Alnuaimy, Lana A.
, p. 271 - 278 (2022/01/22)
A new metal complexes have been synthesized by a reaction of metal compounds contained Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with two kinds of ligands that are 2-carboxy benzaldehyde 4-methylbenzoylhydrazone(CBMH) and 2-carboxy benzaldehyde picolinoyl hydrazine (CBPH), the ligands (CBMH and CBPH) were prepared by condensation of 2-carboxy benzaldehyde with 4-methylbenzoyl hydrazide or picolinoyl hydrazide, respectively. In fact, complexes[M(L-H)2]. xH2O were characterized by elemental analysis, molar conductance, magnetic susceptibility, and spectral measurements (UV-Vis, IR,). The hydrazones CBMH and CBPH act as monobasic tridentate ligands, in all their complexes. The ligand CBMH coordinated to the metal ions through the azomethine nitrogen, the carboxyl group oxygen, and the amide carbonyl group oxygen atoms, while the ligand CBPH coordinated through the carboxyl group oxygen, the azomethine nitrogen, and the pyridine ring nitrogen atoms. Physico-chemical studies suggest octahedral geometry for all metal(II) complexes.
A remarkable energy barrier for spin reversal in a field induced dinuclear ytterbium single molecule magnet
Konar, Sanjit,Mondal, Arpan
supporting information, p. 13666 - 13670 (2021/10/19)
A dinuclear ytterbium complex has been designed with a strong ligand field in equatorial positions. Magnetic studies reveal the presence of easy-axis anisotropy and field induced slow relaxation of magnetization with a remarkable energy barrier,Ueff= 53.58 cm?1, the highest value reported for any Yb-based SMMs to date. Furthermore, theab initiocalculations disclose the importance of a weak axial ligand field to design high-performance Yb-based SMMs.
