- Diaryl-substituted polyethers with acetoacet-anilide fragment in the synthesis of dihydro-pyrimidine-containing podands
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The interaction of ortho-aminoaryl polyethers, derivatives of mono-, di-, and triethylene glycol, with acetyl ketene, generated from 2,2,6-trimethyl-4H-1,3-dioxin-4-one produced acetoacetanilide- containing podands. 2,2,6-Trimethyl-4H-1,3-dioxin-4-one reacted with aminoaryl-substituted podands containing a short polyether chain (1-2 atoms) in toluene medium without catalyst. Acetoacetanilide- containing podands with longer polyether chains could be obtained by using triethylamine or acetic acid as catalyst. Acetoacetanilide-containing podands were used in the Biginelli reaction as CH-active components.
- Radionova,Titova, Yu. A.,Isenov,Fedorova,Rusinov,Charushin
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Read Online
- Long-Term Tracking and Dynamically Quantifying of Reversible Changes of Extracellular Ca2+ in Multiple Brain Regions of Freely Moving Animals
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Understanding physiological and pathological processes in the brain requires tracking the reversible changes in chemical signals with long-term stability. We developed a new anti-biofouling microfiber array to real-time quantify extracellular Ca2+ concentrations together with neuron activity across many regions in the mammalian brain for 60 days, in which the signal degradation was 2+ upon ischemia-reperfusion processes. The changing sequence and rate of Ca2+ in 7 brain regions were different during the stroke. ROS scavenger could protect Ca2+ influx and neuronal activity after stroke, suggesting the significant influence of ROS on Ca2+ overload and neuron death. We demonstrated this microarray is a versatile tool for investigating brain dynamic during pathological processes and drug treatment.
- Liu, Yuandong,Liu, Zhichao,Zhao, Fan,Tian, Yang
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p. 14429 - 14437
(2021/05/03)
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- A Comprehensive Study of the Ca2+ Ion Binding of Fluorescently Labelled BAPTA Analogues
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Since its development, the ionophore BAPTA (1,2-bis(2-aminophenoxy)-ethane-N,N,N’,N’-tetraacetic acid) has been used unchanged in calcium sensing applications. In this work we present a comprehensive experimental and theoretical study of novel alterations in the structure of BAPTA, with a focus on the systematic modification of the chain connecting the two aromatic rings of the molecule (denoted as “linker”). A bis-(diethylamino)xantene fluorophore was also attached to the structures in a fixed position and the structure-fluorescence response relationship of these molecules was investigated in addition. The effect of the linker's length, the number of oxygen atoms in this chain and even the removal of one of the rings was tested; these all proved to significantly alter the characteristics of the compounds. For example, it was found that the second aromatic ring of BAPTA is not essential for the turn-on of the fluorescence. We also demonstrated that successful sensing can be realized even by replacing the chain with a single oxygen atom, which suggests the availability of a new calcium binding mode of the chelator. The reliable turn-on characteristic, the steep Ca2+ fluorescence titration curve and the intense fluorescence emission combine to make this compound a prospective candidate as a calcium sensing molecular probe in diagnostic neurobiological applications.
- Csomos, Attila,Kontra, Bence,Jancsó, Attila,Galbács, Gábor,Deme, Ruth,Kele, Zoltán,Rózsa, Balázs József,Kovács, Ervin,Mucsi, Zoltán
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p. 5248 - 5261
(2021/10/19)
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- [18F] Fluoride Cryptate Complexes for Radiolabeling Fluorinations
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The present invention claims UV detectable (λ>210 nm) potassium [18F]fluoride diaryl- and aryl-fused [2.2.2]cryptate complexes suitable for performing radio-labeling reactions to generate [18F] fluorinated species.
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- A Copper Nanocluster-Based Fluorescent Probe for Real-Time Imaging and Ratiometric Biosensing of Calcium Ions in Neurons
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Fluorescent calcium ion (Ca2+) sensing and imaging have become an essential technique for investigation of signaling pathways of Ca2+ and understanding the role of Ca2+ in neurodegenerative disease. Herein a copper nanocluster (CuNC)-based ratiometric fluorescent probe was developed for real-time sensing and imaging of Ca2+ in neurons, in which a specific Ca2+ ligand with two formaldehyde groups was synthesized and further conjugated with polyethylenimine (PEI) to form a new ligand molecule for the synthesis of CuNCs. Meanwhile, water-soluble Alex Fluor 660 NHS ester was immobilized onto CuNCs as a reference element. The developed ratiometric fluorescence nanoprobe demonstrated a good linearity with Ca2+ concentration in the range of 2-350 μM, and a detection limit down to 220 ± 11 nM was achieved. In addition, the response time of the present probe for Ca2+ was found to be less than 2 s with good stability and high selectivity. Taking advantage of the low cytotoxicity and good biocompatibility of the developed nanoprobe, it was discovered that the histamine-induced cytoplasmic Ca2+ increase in various parts of neurons was different. Moreover, it was found O2--induced cytoplasmic Ca2+ burst and O2--induced neuronal death possibly resulted from Ca2+ overload in the neurons.
- Liu, Zhichao,Jing, Xia,Zhang, Sanjun,Tian, Yang
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p. 2488 - 2497
(2019/02/12)
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- DISAZO YELLOW PIGMENT, PIGMENTS DISPERSION AND PHOTOSENSITIVE RESIN COMPOSITION USING THE SAME
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Novel pigment yellow formation of pigment dispersion including oh settlement compound and disclosure photosensitive resin composition are disclosed. Said discharge oh settlement compounds are high heat resistance and excellent dispersion property, the dispersion of pigment dispersion including same on the base and storage stability. The, said discharge oh settlement using the photosensitive resin compositions have a good coloring compounds including pigment dispersion can be implementing force, such as a high-quality color filter having an excellent optical brightness and contrast can be [...] number. (by machine translation)
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- [18F] fluoride cryptate complexes for radiolabeling fluorinations
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The present invention claims UV detectable (λ>210 nm) potassium [18F]fluoride diaryl- and aryl-fused [2.2.2]cryptate complexes suitable for performing radio-labeling reactions to generate [18F] fluorinated species.
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- Polylactic acid composition
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A resin composition which comprises polylactic acid, does not release an isocyanate group at the time of production and has excellent hydrolysis resistance and a low environmental burden. The resin composition comprises: (A) 100 parts by weight of a resin component (component A) containing polylactic acid (component A-α);(B) 0.001 to 10 parts by weight of a compound (component B) having one carbodiimide group and a cyclic structure in which first nitrogen and second nitrogen are bonded to each other via a bonding group, the cyclic structure consisting of 8 to 50 atoms; and(C) 0.001 to 2 parts by weight of at least one antioxidant (component C) selected from the group consisting of a hindered phenol-based compound, a phosphite-based compound, a phosphonite-based compound and a thioether-based compound.
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- Real-Time Reaction Monitoring of an Organic Multistep Reaction by Electrospray Ionization-Ion Mobility Spectrometry
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The capability of electrospray ionization (ESI)-ion mobility (IM) spectrometry for reaction monitoring is assessed both as a stand-alone real-time technique and in combination with HPLC. A three-step chemical reaction, consisting of a Williamson ether synthesis followed by a hydrogenation and an N-alkylation step, is chosen for demonstration. Intermediates and products are determined with a drift time to mass-per-charge correlation. Addition of an HPLC column to the setup increases the separation power and allows the determination of further species. Monitoring of the intensities of the various species over the reaction time allows the detection of the end of reaction, determination of the rate-limiting step, observation of the system response in discontinuous processes, and optimization of the mass ratios of the starting materials. However, charge competition in ESI influences the quantitative detection of substances in the reaction mixture. Therefore, two different methods are investigated, which allow the quantification and investigation of reaction kinetics. The first method is based on the pre-separation of the compounds on an HPLC column and their subsequent individual detection in the ESI-IM spectrometer. The second method involves an extended calibration procedure, which considers charge competition effects and facilitates nearly real-time quantification.
- Zühlke, Martin,Sass, Stephan,Riebe, Daniel,Beitz, Toralf,L?hmannsr?ben, Hans-Gerd
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p. 1266 - 1273
(2017/11/15)
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- Method using sodium hydrosulfide to prepare 2, 2'-(Ethylenedioxy)dianiline through reduction
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The invention discloses a method using sodium hydrosulfide to prepare 2, 2'-(Ethylenedioxy)dianiline through reduction. The method includes: adding 1, 2-bis(2-nitrophenoxy)ethane, water and sodium hydrosulfide aqueous solution into a high-pressure kettle, feeding nitrogen for replacement, heating, controlling reaction pressure to be 0-0.5Mpa and reaction temperature to be 100-140 DEG C, keeping the temperature for 2-6 hours, and finishing the reaction; discharging pressure and cooling after the reaction, and filtering at 30-35 DEG C to obtain a crude product; using water as the solvent of the crude product, and performing acid dissolution, alkaline reverse adjusting refining and drying to obtain a qualified product. The method has the advantages that the water is used as the solvent, organic solvents such alcohol are not used, reaction yield is larger than 90%, product purity is larger than 99.5%, the waste water generated by the reduction only contains sodium hydrosulfide and sodium thiosulfate, the sodium hydrosulfide is turned into the sodium thiosulfate through oxidizing, the sodium thiosulfate can be reused after water is steamed out, and the method is green, low in equipment requirement and low in investment.
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Paragraph 0023; 0024
(2016/12/01)
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- A fluorescent chemosensor for Hg2+ and Cd2+ ions in aqueous medium under physiological ph and its applications in imaging living cells
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A new BODIPY derivative with 2,2-(ethane-1,2-diylbis(oxy))bis(N,N-bis(pyridine-2-ylmethyl)aniline unit as the metal receptor has been designed and synthesized. The dye selectively detects either Cd2+ or Hg2+ ions in the presence of hosts of other biologically important and environmentally relevant metal ions in aqueous medium at physiological pH. Binding of metal ions causes a change in the emission behavior of the dye from weakly fluorescent to highly fluorescent. Confocal microscopic experiments validate that the dye can be used to identify changes in either Hg2+ or Cd2+ levels in living cells.
- Maity, Shubhra B.,Banerjee, Saikat,Sunwoo, Kyoung,Kim, Jong Seung,Bharadwaj, Parimal K.
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p. 3929 - 3936
(2015/05/04)
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- Structural study and fluorescent property of a novel organic microporous crystalline material
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A novel microporous organic material [(2-{2-[2-(bis- methoxycarbonylmethylamino)phenoxy] ethoxy}-4-benzimidazole-phenyl) methoxycarbonylmethylamino]acetic acid methyl ester 6 was synthesized and characterized by single crystal X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), electron spray ionization-mass spectrometry (ESI-HRMS), X-ray powder diffraction (PXRD), 1H and 13C NMR. 6 crystallizes in the centrosymmetric monoclinic space group C2/c, with unit cell parameters a = 35.648(3) A?, b = 14.3240(12) A?, c = 15.3693(13) A?, α = 90.00, β = 94.8190(10),. = 90.00, V = 7820.16 A?3 and Z = 8 at 296(2) K. As indicated by crystal packing, the molecular conjugation planes arrange along the c axis to form micropores due to the hydrogen bonds. In addition, the fluorescent spectrum and luminescence lifetime were studied for 6.
- Cheng, Zhao,Yang, Bingqin,Yang, Meipan,Zhang, Binglin
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p. 112 - 118
(2014/02/14)
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- Synthesis and spectroscopic properties of new bis-tetrazoles
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Syntheses of N,N′-phenyltetrazole podands link with aliphatic chains containing oxygen, nitrogen and sulphur atoms, are described. The complexing properties of these compounds towards metal cations (Fe2+, Cu 2+, Zn2+, Co2+, Ni2+) were investigated by absorption and infrared spectroscopy. The UV-Vis titrations were performed to estimate the stability constant values of the respective complexes with Cu2+ ion. Changes in UV-Vis absorption spectra and IR spectra of compound 6 under various concentrations of Cu2+ ion in methanol suggest formation of very unstable complex. The structure of ligand 2 has been deduced by X-ray crystallography. The Author(s) 2012.
- Pazik, Agnieszka,Skwierawska, Anna
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- Water-soluble, redox-active organometallic calcium chelators
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This paper describes a new series of organometallic water-soluble chelators combining a redox moiety (ferrocene) and a selective Ca2+ chelator (BAPTA) separated by an ethynyl bridge. We report the synthesis and characterization of organometallic derivatives of the BAPTA chelator featuring one (2a) and two ferrocenyl (2b) moieties. Single crystal X-ray structural analysis on these chelators revealed unexpected conformations for the ferrocenyl substituent with respect to the phenyl ring of the BAPTA unit. DFT calculations on a model system of the ferrocenyl-ethynyl-BAPTA molecule were carried out to evaluate the energy separation between the two limiting conformations observed experimentally in the solid state, and to check the effective electronic communication between the binding pocket and the redox probe. The binding affinity of 2a-b for Ca2+, as probed by UV-Vis and cyclic voltammetry, revealed distinct behaviors in the presence of a metal ion depending on whether BAPTA is substituted by one or two ferrocenyl groups.
- Bhattacharyya, Koyel X.,Boubekeur-Lecaque, Le?la,Tapsoba, Issa,Maisonhaute, Emmanuel,Sch?llhorn, Bernd,Amatore, Christian
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p. 14257 - 14264
(2013/04/10)
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- CYCLIC CARBODIIMIDE COMPOUNDS
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A cyclic carbodiimide compound which is useful as an end-sealing agent for polymer compounds. The cyclic carbodiimide compound is represented by the following formula (i): In the above formula, X is a divalent group or a tetravalent group represented by the following formula (i-4). When X is divalent, q is 0 and when X is tetravalent, q is 1. Ar1 to Ar4 are each independently an aromatic group. They may be substituted by an alkyl group having 1 to 6 carbon atoms or phenyl group.
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- Hg2+-selective ratiometric and "off-on" chemosensor based on the azadiene-pyrene derivative
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A new pyrene-based derivative bearing an azadiene group was synthesized as a ratiometric chemosensor for Hg2+ in aqueous acetonitrile solution. The "off-on" type signaling behavior of the fluoroionophore is due to the metal ion induced conformational changes from the weak pyrene monomer emissions to strong pyrene excimer emission.
- Zhou, Yi,Zhu, Chao-Yun,Gao, Xu-Sheng,You, Xue-Yan,Yao, Cheng
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supporting information; experimental part
p. 2566 - 2569
(2010/07/20)
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- Synthesis of a [2.2.2] cryptand containing reactive functional groups
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The functional group- containing potassium ionophore 195, 245 dibromo-4,7,13,16,20,23-hexaoxa-1,10 diaza-19(1,2), 24(1,2 dibenzabicyclo[8.8.6] tetracosaphane has been synthesized.
- Naguib, Yousry M.A.
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experimental part
p. 3600 - 3609
(2010/03/03)
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- Ultralow calcium requirements of fungi facilitate use of calcium regulating agents to suppress host calcium-dependent defenses, synergizing infection by a mycoherbicide
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Infection by many fungi activates a variety of calcium dependent defenses in the hosts, slowing or suppressing the attacker and limiting the efficacy of mycoherbicides. The calcium requirement for fungal growth is so low that it could only be implied based on fungi containing calcium-dependent signaling enzymes. Analytical grade media contain 2 μM calcium, and the addition of specific chelators does not affect fungal growth. Hydrophobic derivatives of the calcium-specific chelator BAPTA designed to traverse plant cuticles were synthesized in order to chelate calcium internally during fungal attack. Some chelators as well as calcium precipitating oxalate and channel blocker verapamil were applied with a weakly mycoherbicidal Colletotrichum coccodes to cotyledons of compatible Abutilon threophrasti. They suppressed calcium dependent callose biosynthesis in the weed and increased virulence but may have affected other calcium-dependent processes that facilitate virulence. The low calcium requirement of fungi, and their high affinity for calcium, allows the application of calcium-regulating agents as synergists for mycoherbicides where the weed uses calcium-dependent defenses.
- Gressel, Jonathan,Michaeli, Daphna,Kampel, Vladimir,Amsellem, Ziva,Warshawsky, Abraham
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p. 6353 - 6360
(2007/10/03)
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- SYNTHESIS OF BAPTA-AM ANALOGUES CAPABLE OF ENHANCING THE VASCULAR PRODUCTION OF PROSTACYCLIN
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About 30 analogues of BAPTA-AM, a potential antithrombotic agent, have been synthesized and tested for their effect on the production of prostacyclin.None of them was found to be a better enhancher of the production of prostacyclin by aortic endothelial cells than BAPTA-AM itself.The enhancing effect can be produced by compounds unable to chelate Ca2+, thus confirming that it is not related to their buffering capacity for free Ca2+.
- Heilporn, S.,Broeders, F.,Daloze, D.,Braekman, J. C.,Boeynaems, J. M.
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p. 309 - 320
(2007/10/02)
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- Preparation and Characterization of New Amino-Substituted Crowns and Podands
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A number of macrocyclic (1b-3b) and linear oligoether compounds (4b-8b) with 2,2'-methylenebis(4-aminophenol) or 2-aminophenol characteristic building blocks have been synthesized by reduction of the corresponding nitro derivatives with Pd-C/hydrazine hydrate.The pKa' values of the new compounds have been determined by potentiometric titration.These and the observed spectroscopic data are discussed and compared with related compounds.A crystalline 1:1 complex of the diamino crown 3b with NaSCN has also been prepared and characterized. Keywords: Amino Crowns, Amino Podands, Synthesis, Spectroscopic Studies
- Kilic, Zeynel,Weber, Edwin,Guenduez, Necla,Kilic, Emine,Nazir, Hasan,et al.
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p. 547 - 552
(2007/10/02)
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- Macroheterocycles with an Endocyclic Azo-Group. 1. Tetraazamacrocycles Obtained from Resorcinol
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High-dilution azocoupling of bisdiazotized bis-(2-aminophenyl)oligooxa (or thia)alkanes with resorcinol gives tetraazamacrocycles with two endocyclic azogroups.It is shown that azocoupling occurs exclusively at the 2- and 4-positions of the resorcinol ring.
- Sultanov, A. V.,Savvin, S. B.
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p. 106 - 109
(2007/10/02)
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- SYNTHESIS OF MACROHETEROCYCLES, ANALOGS OF DIBENZO-CROWN COMPOUNDS. 1. 15-MEMBERED OXATHIADIAMINES
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Macrocyclic diamides have been synthesized by the condensation of 1,4-bis(2-aminophenyl)-1,4-dioxa(dithia)butanes with the diacid chlorides of glutaric, diglycolic, and thiodiglycolic acids under conditions of high dilution.Subsequent reduction with diborane led to the corresponding macrocyclic diamine containing atoms of oxygen and (or) sulfur.Structural assignments were made using data of mass spectrometry and IR, PMR, and 13C NMR spectra.
- Formanovski, A. A.,Murakhovskaya, A. S.
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p. 225 - 229
(2007/10/02)
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- Synthesis, N.m.r. Spectra, and Structure of Macrocyclic Compounds containing the Ferrocene Unit
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The condensation of 1,1'-bis(chlorocarbonyl)ferrocene with diaza-18-crown-6 gives 1,1'-(1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane-7,16-diyldicarbonyl)ferrocene (5) together with its dimer 1,1'':1',1'''-bis-(1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane-7,16-diyldicarbonyl)bisferrocene (6) and the separation and isolation of these compounds are described.High resolution 1H and 13C n.m.r. spectra using homo- and hetero-nuclear decoupling techniques allow a complete assignment of the spectral data for (5) and (6) and lead to a proposal of a structure for (5) involving a trans-disposition of the amide carbonyl groups.Variable-temperature n.m.r. data on (6) reveal two distinct dynamic processes within the molecule involving rotation about the ferrocene-carbonyl bond (ΔG=50 kJ mol-1, Tc=-10 deg C) and rotation about the N-CO bond (ΔG=67 kJ mol-1, Tc=+60 deg C).The preparation, 1H and 13C n.m.r. data of monocyclic compounds containing the ferrocene unit (13a-c), (14) and (15) are also described and the details of the synthesis of an 15N-labelled analogue of (13c), the macrocycle (16), are reported.
- Hammond, Philip J.,Bell, Alan P.,Hall, C. Dennis
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p. 707 - 715
(2007/10/02)
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