129409-01-4Relevant articles and documents
Luminescent bi-metallic fluoroborate derivatives of bulky salen ligands
Guieu, Samuel,Cardona, Francisco,Rocha, Joo,Silva, Artur M. S.
, p. 5411 - 5414 (2014)
A family of hemisalen fluoroborate complexes has been prepared and characterized. These new fluorophores exhibit an intense blue emission upon irradiation with UV light. Interestingly, the introduction of bulky aromatic substituents enhanced the quantum yield considerably, up to 44%. Upon studying various solvents, it appeared that the effect of the phenyl substituents is more of electron donating nature than of restricting the intramolecular motion of the dyes. This journal is
A family of silatrane-armed triazole-encapped salicylaldehyde-derived Schiff bases: Synthesis, spectral analysis, and antimicrobial and quantum chemical evaluation
Singh, Gurjaspreet,Arora, Aanchal,Rani, Sunita,Kalra, Pooja,Aulakh, Darpandeep,Wriedt, Mario
, (2017)
This work describes the successful synthesis of salicylaldehyde-derived Schiff base-linked organosilicon compounds following a highly efficient click approach. Hydroxyl-terminated Schiff bases were alkylated to bis-acetylenes (1–3) which upon 3?+?2 cycloaddition with 3-azidopropyltriethoxysilane yielded triazole-decorated bis-silanes (4–6). These silanes further underwent base-catalyzed transesterification to afford Schiff base-linked triazole-bound organosilatranes (7–9). The final silatranes as well as precursor alkynes and silanes were comprehensively characterized using NMR (1H and 13C) and infrared spectroscopic techniques together with elemental analysis and mass spectrometry of compounds 7–9. Also, the structures of alkynes 1–3 and silatrane 7 were validated using single-crystal X-ray crystallography. Organosilatranes were initially screened for their pharmacokinetic profile using absorption, distribution, metabolism, excretion and toxicity (ADMET) tools and then explored for their antimicrobial activities, with compound 9 emerging as the most potent antimicrobial agent. Compounds 1–3 and 7–9 also underwent thorough computational analysis by applying the density functional theory (DFT) approach with B3LYP/6-31G(d) level of theory and the results were found to be consistent with the experimental data. Several DFT-based descriptors were also evaluated providing a valuable insight into molecular stability and reactivity.
Methylene spacer-regulated structural variation in cobalt(II/III) complexes with bridging acetate and salen- or salpn-type Schiff-base ligands
Chattopadhyay, Shouvik,Drew, Michael G. B.,Ghosh, Ashutosh
, p. 1693 - 1701 (2008)
Two linear, trinuclear mixed-valence complexes, [CoII{(μ- L1)-(μ-OAc)CoIII(OAc)}2] (1) and [Co II{(μ-L2)(μ-OAc)CoIII(OAc)}2] (2) and two mononuclear CoIII complexes [CoIII{L 3}(OAc)] (3), and [CoIII{L4}(OAc)] (4) were prepared and the molecular structures of 1, 2 and 4 elucidated on the basis of X-ray crystallography [OAc = Acetate ion, H2L1 = H 2Salen = 1,6-bis(2-hydroxyphenyl)-2,5-diazahexa-1,5-diene, H 2L2 = H2Me2-Salen = 2,7-bis(2-hydroxyphenyl)-2,6-diazaocta-2,6-diene, H2L3 = H2Salpn = 1,7-bis(2-hydroxyphenyl)-2,6-diazahepta-1,6-diene, H 2L4 = H2Me2Salpn = 2,8-bis(2-hydroxyphenyl)-3,7-diazanona-2,7-diene]. In complexes 1 and 2, the acetate groups show both monodentate and bridging bidentate coordination modes, whereas chelating bidentate acetate is present in 4. The terminal Co IIIN2O4 centres in 1 and 2 exhibit uniform facial arrangements of both non-bridged N2O and bridging O 3 donor sets and the CoII centre is coordinated to six (four phenoxo and two acetato) oxygen atoms of the bridging ligands. The effective magnetic moment at room temperature corresponds to the presence of high-spin CoII in both 1 and 2. The complexes 1 and 2 are thus CoIII(S = 0)-CoII(S = 3/2)-CoIII(S = 0) trimers. Complexes 3 and 4 are monomeric and diamagnetic containing low-spin CoIII(S = 0) with chelating tetradentate Schiff base and bidentate acetate. Calculations based on DFT rationalise the formation of trinuclear or mononuclear complexes. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Synthesis, characterization, optical spectroscopic, electronic structure, and second-order nonlinear optical (NLO) properties of a novel class of donor-acceptor bis(salicylaldiminato)nickel(II) Schiff base NLO chromophores
Di Bella, Santo,Fragalà, Ignazio,Ledoux, Isabelle,Diaz-Garcia, Maria A.,Marks, Tobin J.
, p. 9550 - 9557 (1997)
The synthesis, characterization, thermal stability, optical spectroscopic, electronic structure, and second-order nonlinear optical (NLO) response of a series of donor-acceptor bis(salicylaldiminato)nickel(II) Schiff base complexes and the free ligand precursors are reported. The effect of the metal center in such complexes is manifold: it templates the formation of acentric molecular structures, imparts high thermal stability to the chelate ring, and both 'switches on' and enhances NLO response. Metal complexation imparts new linear optical spectroscopic features, having metal-to-ligand charge transfer character, which are responsible for the second-order nonlinearity. Moreover, the present synthetic strategy represents a novel route to inorganic NLO chromophores. Solution-phase hyperpolarizability values, deduced by electric field-induced second-harmonic-generation experiments are as high as -79 x 10-30 cm5 esu-1 (hω = 0.92 eV). Experimental linear and nonlinear optical features are fully consistent with INDO/SCI-SOS theoretical calculations. They provide a rationale for the NLO response of these materials and are attractive for designing new, highly efficient second-order nonlinear optical inorganic chromophores.
Cubane Structure of Sodium Derivatives of Tetradentate Schiff Bases
Solari, Euro,Angelis, Stefania De,Floriani, Carlo,Chiesi-Villa, Angiola,Rizzoli, Corrado
, p. 2471 - 2476 (1991)
Reaction of sodium hydride in thf (thf = tetrahydrofuran) with H2salphen or H2salen gave the corresponding sodium derivatives Na2(salphen)(thf)n and Na2(salen)(thf)n.Recrystallization from 1,2-dimethoxyethane (dme) gave the stable solvated forms 1 and 2.From the X-ray analysis both have very similar structures with a cubane skeleton of alternate sodium and oxygen atoms.Crystallographic details: complex 1, space group P21/c, a = 12.045(1), b = 25.851(2), c = 16.467(1) Angstroem, α = γ = 90 deg, β = 107.61(1) deg, Z = 4 and R = 0.079 for 2118 independent observed reflections; 2, space group P21/n, a = 20.493(2), b = 21.682(2), c = 20.538(2) Angstroem, α = 90 deg, β = 110.53(1) deg, Z = 8 and R = 0.071 for 5054 independent observed reflections.
Effects of diamine bridge length and substituents on the spectral properties of N,N′-bis(α-substituted salicylidene)diamines in solution
Kawasaki, Toshio,Kamata, Toshihide,Ushijima, Hirobumi,Kanakubo, Mitsuhiro,Murata, Shigeo,Mizukami, Fujio,Fujii, Yuki,Usui, Yoshiharu
, p. 193 - 198 (1999)
Absorption and fluorescence spectra of thirteen N,N′-bis(α-substituted salicylidene)diamines in solution were investigated with the intention of investigating the role of the substituent and diamine bridge length on their optical properties. The fluorescence efficiency was improved by an increase in the electron-donating property of the substituents on the azomethine carbon accompanied by an increase of the n→π* transition absorption. However, the effect did not occur for the substituents on the azomethine nitrogen, in which no drastic changes in fluorescence efficiency could be observed. Through the investigation of the diamine bridge length effects, it was found that a diamine Schiff base seems to form neither an inter- nor an intramolecular dimer with any peculiar fluorescence in the solution even if it has a long methylene bridge. It was also suggested that the diamine Schiff base has a third fluorescence species in the excited state, which might be a pre-keto form, the existence of which is strongly affected by the hydrogen bond strength between the hydroxy and azomethine groups.
Design, synthesis and biological evaluation of Schiff’s base derivatives as multifunctional agents for the treatment of Alzheimer’s disease
Shi, Jian,Zhou, Yi,Wang, Keren,Ma, Qinge,Wei, Rongrui,Li, Qingfeng,Zhao, Yiyang,Qiao, Zhanpin,Liu, Shuang,Leng, Yumin,Liu, Wenmin,Sang, Zhipei
, p. 624 - 634 (2020/11/30)
A series of Schiff’s base derivatives was rationally designed, synthesized, and evaluated as multi-function agents for the treatment of Alzheimer’s disease (AD). The results revealed that compound 3b was a novel multifunctional agent. It acted as a highly selective monoamine oxidase-B inhibitor (IC50 = 8.4 nM), which was explained by the docking study. Compound 3b also was an antioxidant agent (2.3 eq) and could significantly inhibit self-induced Aβ1-42 aggregation (31.8%). Meanwhile, compound 3b was a selective metal chelator and could inhibit Cu2+-induced Aβ1-42 aggregation (62.3%). Furthermore, compound 3b presented good neuroprotective effects on H2O2-induced PC12 cell injury. More importantly, compound demonstrated good blood brain barrier permeability and druglike properties. Therefore, compound 3b, a promising multi-targeted active molecule, offers an attractive starting point for further study in the drug-discovery process against AD.[Figure not available: see fulltext.].
Synthesis and antibacterial studies of some reduced schiff base derivatives
Patil, Udaysinha,Khan, Asif,Nagarsekar, Aarti,Mandewale, Mustapha,Yamgar, Ramesh
, p. 2796 - 2805 (2019/01/05)
A series of N,N-substituted ethylene-1,2-diamine derivatives have been prepared from reaction of 2-hydroxybenzaldehyde derivatives and 1,2-diamine derivatives in the presence of NaBH4 through Schiff base intermediate. The synthesized compounds were screened for their antibacterial activities. Compound SB01, SB02 and SB09 displayed significant activity at MIC ranges from 0.40-6.25 μg/mL.
