Reactivity of monohydrogensulfide with a suite of pyridoxal-based complexes: A combined NMR, ESI-MS, UV–visible and fluorescence study
摘要:
In the present work, we explored the reactivity of HS- with a family of fluorescent metal complexes via a variety of spectroscopic techniques. The complexes under investigation are obtained by complexation of zinc or nickel with pyridoxal-based ligands. More specifically complexes 1 and 2 are zinc complexes namely L1 Zn(II) and L2Zn(II) where L1 stands for N,N'-phenylenebis(pyridoxyliminato) and L2 is N,N'-binaphthylenebis(pyridoxyliminato), whereas complex 3 is a nickel complex (L3Ni(II)) where L3 is N,N'-ethylenebis(pyridoxyliminato). A combination of NMR, ESI-MS, UV-vis and fluorescence experiments provide evidence that HS- binds the metal center in the case of complexes 1 and 3 whereas for complex 2, ZnS precipitation and hydrolysis of the organic ligand occur. Fluorescence experiments indicate that in the presence of HS- complex 1 undergoes a consistent fluorescence enhancement whereas for complex 3 the parent fluorescence exhibits a visible quenching. The results highlight the potential of complex 1 to be implemented as a HS- fluorescent sensor via a coordinative-based approach.
Synthesis, experimental and theoretical characterization of a Mn(II) complex of N,N′-dipyridoxyl(1,2-diaminobenzene)
作者:Tina Toozandejani、S. Ali Beyramabadi、Hamed Chegini、Maryam Khashi、Ali Morsali、Mehdi Pordel
DOI:10.1016/j.molstruc.2016.07.026
日期:2017.1
catalytic applications, synthesis of a Mn(II) complex of the N,N′-dipyridoxyl(1,2-diaminobenzene) [H 2L] Schiff-base has been reported. The Mncomplex was characterized experimentally and theoretically. The optimized geometry and vibrational frequencies of the complex were computed by using the density functional theory (DFT) methods. In the optimized geometry of the octahedral complex, the dianionic L2−
Cu(II) Complex of a Schiff Base Derived from Pyridoxal: Synthesis, Experimental Characterization, DFT Studies, and Aim Analysis
作者:N. Samini、S. A. Beyramabadi、F. F. Bamoharram
DOI:10.1134/s0022476619080067
日期:2019.8
A Cu(II) complex of the N,N′-dipyridoxyl(1,2-diaminobenzene) [=H2L] Schiffbase is newly synthesized. The complex is characterized experimentally and theoretically. The density functional theory methods are employed to calculate the optimized geometry along with the natural bond orbital analysis and the vibrational frequency analysis of the complex. The computed IR frequencies are in agreement with
An aggregation-induced emissive pyridoxal derived tetradentate Schiff base for the fluorescence turn-off sensing of copper(<scp>ii</scp>) in an aqueous medium
作者:Vinita Bhardwaj、Lavani Hindocha、SK Ashok Kumar、Suban K Sahoo
DOI:10.1039/d1nj05523b
日期:——
In this study, a tetradentate Schiffbase ligand L was synthesized by condensing o-phenylenediamine with two moles of pyridoxal. The solution of L in EtOH/DMSO showed aggregation-induced emission (AIE) behaviour with the addition of water. The weakly emissive L in EtOH/DMSO at 474/442 nm showed a blue-shifted fluorescenceenhancement at 380 nm with the addition of water/HEPES buffer. The aggregation
在这项研究中,通过将邻苯二胺与两摩尔吡哆醛缩合合成了四齿席夫碱配体L。L在 EtOH/DMSO 中的溶液在加入水时表现出聚集诱导发光 (AIE) 行为。加入水/HEPES 缓冲液后,EtOH/DMSO 中 474/442 nm 处的弱发射L在 380 nm 处显示出蓝移荧光增强。DLS 和 SEM 分析支持L的聚合。由于聚集时分子内旋转 (RIR) 的限制,C N 异构化的阻断将弱发射L转化为高蓝色荧光L。L的聚合体在混合 EtOH:HEPES 缓冲液(5% EtOH,pH = 7.4)介质中探索了金属离子的荧光传感。Cu 2+的加入与L以1:1 的结合比例形成复合物,由于Cu 2+的顺磁性和ESIPT 的抑制作用,L的荧光猝灭。通过紫外-可见和荧光技术估计的络合物L - Cu 2+的结合常数分别为1.36 × 10 4 M -1和3.63 × 10 4 M -1。L的猝灭荧光通过添加强螯合剂
N,N′-dipyridoxyl Schiff bases: Synthesis, experimental and theoretical characterization
作者:S. Ali Beyramabadi、Ali Morsali、Malihe Javan Khoshkholgh、Abbas Ali Esmaeili
DOI:10.1016/j.saa.2011.08.067
日期:2011.12
Three N,N'-dipyridoxyl Schiff bases (L1, L2 and L3) have been newly synthesized and characterized by IR, (1)H NMR, mass spectrometry and elemental analysis. Their optimized geometries together with the theoretical assignment of the vibrational frequencies and the (1)H NMR chemical shifts of them have been computed by using density functional theory (DFT) method. In the optimized structures of the Schiff bases, two pyridine rings are not in a same plane; however the substitutions are essentially in the same plane with the pyridine rings. Also, the benzene ring(s) in the bridge region is (are) not in the same plane with the pyridine rings and azomethine moieties. In all the species, engagement in intramolecular-hydrogen bonds causes to weakness of the phenolic O-H bonds. Consistency between the theoretical results and experimental evidence confirms suitability of the optimized geometries for the synthesized Schiff bases. (C) 2011 Elsevier B.V. All rights reserved.
Reactions of pyridoxal with aromatic diamines
作者:Roza Kh. Bagautdinova、Lyudmila K. Kibardina、Alexander R. Burilov、Anna G. Strelnik、Mikhail A. Pudovik
DOI:10.1007/s10593-020-02663-y
日期:2020.3
monoimines were obtained by the reaction of pyridoxal with aromaticdiamines. A change in the ratio of the reagents or introduction of another aromatic aldehyde into the reaction leads to the formation of symmetric and asymmetric diimines. In some cases, the initially formed diimines are transformed into the corresponding benzimidazoles. The products of the reaction of pyridoxal with 1,3-diaminobenzene