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1.
Two 4,5-disubstituted-1,8-naphthalimide derivatives 1 and 2 were synthesized as ratiometric fluorescent and colorimetric sensors for Cu2+, respectively. In 100% aqueous solutions of 1, the presence of Cu2+ induces a strong and increasing fluorescent emission centered at 478 nm at the expense of the fluorescent emission of 1 centered at 534 nm. Compound 2 senses Cu2+ by means of a colorimetric (primrose yellow to pink) method with a thorough quench in emission attributed to the deprotonation of the secondary amine conjugated to the naphthalimide fluorophore. 1-Cu2+ and 2-Cu2+ sense cyanide in ratiometric way via colorimetric and fluorescent changes.  相似文献   

2.
Three monomeric boratranes B[(OCH2CH2)nN(CH2CMe2O)3−n] (n = 0, 1; n = 1, 2; n = 2, 3) have been synthesized by the reaction of B(OMe)3 with a series of triethanolateamines such as [(OCH2CH2)nN(CH2CMe2O)3−n]3− (n = 0, L1; n = 1, L2; n = 2, L3), where the number of CMe2 groups adjacent to the OH functionality varied from 3 (L1H3) to 2 (L2H3) to 1 (L3H3). These boratranes 1-3 have been characterized by solution 1H, 13C{1H} and 11B NMR, and the crystal structures of 1 and 2 have been determined by single crystal X-ray diffraction.  相似文献   

3.
The synthesis, characterization and thermal behaviour of some new dimeric allylpalladium (II) complexes bridged by pyrazolate ligands are reported. The complexes ; R = H, R′ = C(CH3)3 (1b), R = H, R′ = CF3 (1c); R = CH3, R′ = CH(CH3)2 (2a); R = CH3, R′ = C(CH3)3 (2b); and R = CH3, R′ = CF3 (2c)] have been prepared by the room temperature reaction of [Pd(η3-CH2C(R)CH2)(acac)](acac = acetylacetonate) with 3,5-disubstituted pyrazoles in acetonitrile solution. The complexes have been characterized by NMR (1H, 13C{1H}), FT-IR, and elemental analyses. The structure of a representative complex, viz. 2c, has been established by single-crystal X-ray diffraction. The dinuclear molecule features two formally square planar palladium centres which are bridged by two pyrazole ligands and the coordination of each metal centre is completed by allyl substituents. The molecule has non-crystallographic mirror symmetry. Thermogravimetric studies have been carried out to evaluate the thermal stability of these complexes. Most of the complexes thermally decompose in argon atmosphere to give nanocrystals of palladium, which have been characterized by XRD, SEM and TEM. However, complex 2c can be sublimed in vacuo at 2 mbar without decomposition. The equilibrium vapour pressure of 2c has been measured by the Knudsen effusion technique. The vapour pressure of the complex 2c could be expressed by the relation: ln (p/Pa)(±0.06) = −18047.3/T + 46.85. The enthalpy and entropy of vapourization are found to be 150.0 ± 3 kJ mol−1 and 389.5 ± 8 J K−1 mol−1, respectively.  相似文献   

4.
A new fluorescein-based chemodosimeter (II) for Hg2+ ion was designed and synthesized, and it displayed excellent selective and sensitive toward Hg2+ ion over other commonly metal ions in aqueous media. II was a colorless, non-fluorescent compound. Upon addition of Hg2+ to the solution of II, the thiosemicarbazide moiety of II would undergo an irreversible desulfurization reaction to form its corresponding oxadiazole (IV), a colorful and fluorescent product. During this process, the spirocyclic ring of II was opened, causing instantaneous development of visible color and strong fluorescence emission in the range of 500-600 nm. Based on the above mechanism, a fluorogenic Hg2+-selective chemodosimeter was developed. The fluorescence increase is linearly with Hg2+ concentration up to 1.0 μmol L−1 with a detection limit of 8.5 × 10−10 mol L−1 (3σ). Compared with the rhodamine-type chemodosimeter, II is more stable in aqueous media and exhibits higher sensitivity toward Hg2+. The findings suggest that II will serve as a practical chemodosimeter for rapid detection of Hg2+ concentrations in realistic media.  相似文献   

5.
Chemosensors 5-7 possessing a quaternary ammonium cation (for electrostatic interactions) and an N-H group(s) (for H-bonding) as recognition sites and an anthracene-9,10-dione as both a chromogenic and fluorescent moiety exhibit absorption and emission changes with fluoride ions only. No significant response to other anions such as Cl, Br, I, , CH3COO, , and is observed. The dual emission at λmax 580 nm (free 5/6) and λmax 510 and 540 nm (5/6 + F) in chemosensors 5 and 6 enables ratiometric analysis of fluoride ions.  相似文献   

6.
A new thiacalix[4]arene derivative 2 of 1,3-alternate conformation possessing two pyrene groups has been synthesized and examined for its cation recognition abilities towards different cations such as lithium, sodium, potassium, nickel, zinc, cadmium, silver, mercury, lead and copper by fluorescence spectroscopy. In CH3CN/CH2Cl2 (1:1), the presence of Cu(II) induces the formation of a 1:2 ligand/metal complex, which exhibits increasing monomer emission at 376 nm at the expense of the fluorescent excimer emission of 2 centered at 476 nm. In the presence of K+, the intensity of the excimer emission increases along with the formation of a new blue shifted band at 435 nm which corresponds to a static dimer. The compound behaves as a fluorescent molecular switch upon chemical input of Cu2+ and K+.  相似文献   

7.
Highly selective detection of Hg2+ ion has been achieved using the push–pull-type purine nucleoside-based fluorescent sensor L1. The sensor L1 incorporating aza-18-crown-6 at C6 position of purine nucleoside, is highly sensitive and selective toward Hg2+ ion in CH3CN–H2O mixture (92/8, v/v). The detection limit for the fluorescent sensor L1 toward Hg2+ ion is 7.8 × 10−8.  相似文献   

8.
A ratiometric fluorescent turn-on probe for fluoride ion, based on modulation of the excited-state intramolecular proton transfer (ESIPT) process by chemodosimetric desilylation pathway is reported. The probe SNBT (silyl protected hydroxynaphthalene benzothiazole moiety) shows a significant increase of ratiometric absorption band at 440 nm and emission band at 477 nm by the deprotection of fluoride mediated silyl bond cleavage in CH3CN–H2O (8/2, v/v, 25 °C). The test strips based on SNBT and F are fabricated, which can act as a convenient and efficient F test kits. Furthermore, the biological application shows that it can be very useful as a selective fluoride probe in the fluorescence imaging of living cells.  相似文献   

9.
The metallacyclic complexes (OC)4MC(η2-NHCH2CHCHX)Fc (4; X = H) and (5; X = CH2OH) [M = Cr: a; Mo: b; W: c; Fc = ferrocenyl = CpFe(C5H4)] were obtained in good yields upon photo-decarbonylation of the bimetallic allylaminocarbene complexes (OC)5MC(NHCH2CHCHX)Fc (2; X = H)/(3; X = CH2OH). At room temperature complexes 2/3 exist as mixtures of E- and predominantly Z-isomers with regard to the C-N bond. The molecular structures of 4b and 4c were determined by X-ray diffraction analyses. The intermetallic communicative effects and the interplay of Fc and η2-alkene moieties of 4a and 4b were assessed by cyclovoltammetry. All complexes were also characterized in solution by one- and two-dimensional NMR spectroscopy (1H, 13C, 1H NOE, 1H/1H COSY, 13C/1H HETCOR).  相似文献   

10.
Based on a boron dipyrromethene (BODIPY) derivative containing an N, O and S tridentate ligand, a Cu2+ fluorescent probe BTCu was developed. The detection mechanism was verified as Cu2+-promoted oxidative dehydrogenation of an amine moiety, leading to a formation of a fluorescent Cu+-Schiff base complex. Free BTCu exhibited a maximum absorption wavelength at 496 nm, and a very weak maximum emission at 511 nm. Upon addition of various metals ions, it showed large fluorescence enhancement toward Cu2+ (417-fold in MeCN and 103-fold in MeCN/HEPES solution, respectively) with high selectivity. The detection limits are as low as 1.74 × 10−8 M and 4.96 × 10−8 M in the two different solutions, respectively. And BTCu could work in a wide pH range with an extraordinary low pKa of 1.21 ± 0.06. Using fluorescence microscopy, the probe was shown to be capable of penetrating into living cells and imaging intracellular Cu2+ changes.  相似文献   

11.
A ratiometric fluorescent probe 1 for fluoride ion was developed based on modulation of the excited-state intramolecular proton transfer (ESIPT) process of 2-(2′-hydroxyphenyl)benzimidazole (HPBI) through the hydroxyl group protection/deprotection reaction. The probe 1 was readily prepared by the reaction of HPBI with tert-butyldimethylsilyl chloride (TBS-Cl) and shows only fluorescence emission maximum at 360 nm. Upon treatment with fluoride in aqueous DMF solution, the TBS protective group of probe 1 was removed readily and ESIPT of the probe was switched on, which resulted in a decrease of the emission band at 360 nm and an increase of a new fluorescence peak around 454 nm. The fluorescent intensity ratio at 454 and 360 nm (I454/I360) increases linearly with fluoride ion concentration in the range 0.3-8.0 μmol L−1 and the detection limit is 0.19 μmol L−1. The proposed probe shows excellent selectivity toward fluoride ion over other common anions. The method has been successfully applied to the fluoride determination in toothpaste and tap water samples.  相似文献   

12.
New fluorescent peptide-based sensors (13) for monitoring heparin in serum sample were synthesized using short peptides (1∼3mer) as a receptor. The peptide-based sensors (2 and 3) showed a sensitive ratiometric response to heparin both in aqueous buffered solution (10 mM HEPES, pH 7.4) and in 2% human serum sample by increase of excimer emission of pyrene at 480 nm and concomitant decrease of monomer emission of pyrene at 376 nm, whereas the peptide-based sensor 1 showed a turn off response only by decrease of monomer emission at 376 nm. 2 and 3 exhibited excellent selectivity toward heparin among various anions and competitors of heparin including chondroitin 4-sulfate (ChS) and hyaluronic acid (HA). Peptide-based sensor 3 showed a more sensitive response to heparin than 2. The detection limit of 3 was determined as 36 pM (R2 = 0.998) for heparin in aqueous solution and 204 pM (R2 = 0.999) for heparin in aqueous solutions containing 2% human serum. The peptide-based sensors, 2 and 3 provided a practical and potential tool for the detection and quantification of heparin in real biological samples.  相似文献   

13.
An efficient method for the preparation of carbosiloxane dendrimers with end-grafted SiH-bonds is given by using the alcohols HOCH(Me)(CH2)4SiMe3 − nHn (4a: n = 1, 4b: n = 2, 4c: n = 3), which themselves are accessible by the hydrosilylation of MeCOCH2CH2CHCH2 (1) with the chlorosilanes HSiMe3 − nCln (2a: n = 1, 2b: n = 2, 2c: n = 3) and hydrogenation of the latter species with Li[AlH4]. Alcohols 4a-4c can be used as starting materials for the preparation of carbosiloxane dendrimers of the 1st-3rd generation. For the synthesis of the 1st generation dendrimers, Me4 − mSiClm (5a: m = 1, 5b: m = 2, 5c: m = 3, 5d: m = 4) is reacted with 4a-4c in presence of NEt3 as base. The dendritic molecules Me4 − mSi[OCH(Me)(CH2)4SiMe3 − nHn]m (n = 1: 6a, m = 1; 6b, m = 2; 6c, m = 3; 6d, m = 4. n = 2: 7a, m = 1; 7b,m = 2; 7c, m = 3; 7d, m = 4. n = 3: 8a, m = 3; 8b, m = 4) are thereby obtained in excellent yield. Carbosiloxane dendrimers of the 2nd and 3rd generation with a MeSiO3- or SiO4-core can be isolated from the reaction of MeSi(OCH2CH2CH2SiMe2Cl)3 (9), MeSi(OCH2CH2CH2SiMeCl2)3 (11), Si(OCH2CH2CH2SiMe2Cl)4 (13) and MeSi(OCH2CH2CH2SiMe(OCH2CH2CH2SiMe2Cl)2)3 (15) with 4a or 4b, respectively, under similar reaction conditions. Thereby MeSi[OCH2CH2CH2SiMe2OCH(Me)(CH2)4SiMe2H]3 (10), MeSi[OCH2CH2CH2SiMe[OCH(Me)(CH2)4SiMe3 − nHn]2]3 (12a, n = 1; 12b, n = 2), Si[OCH2CH2CH2SiMe[OCH(Me)(CH2)4SiMe2H]2]4 (14) and MeSi[OCH2CH2CH2SiMe[OCH2CH2CH2SiMe2OCH(Me)(CH2)4SiMe3 − nHn]2]3 (16) are formed as colourless oils.Compounds 3, 4, 6-8, 10, 12, 14 and 16 were characterised by elemental analysis as well as spectroscopic (IR, NMR) and mass spectrometric (ESI-TOF) studies.  相似文献   

14.
Reaction of 1,3-diaryltriazenes (R-C6H4-NN-(NH)-C6H4-R, R = OCH3, CH3, H, Cl, NO2 at the para position) with [Rh(PPh3)3Cl] in ethanol in the presence of a base (NEt3) affords a family of yellow complexes (1-R) containing a PPh3, two de-protonated triazenes coordinated as bidentate N,N-donors, and an aryl (C6H4-R) fragment coordinated in the η1-fashion. A similar reaction in toluene yields a group of reddish-orange complexes (2-R) containing a PPh3, two N,N-coordinated triazenes, and a chloride. Structures of the 1-CH3 and 2-CH3 complexes have been determined by X-ray crystallography. All the 1-R and 2-R complexes are diamagnetic, and show characteristic 1H NMR signals and intense MLCT transitions in the visible region. The 1-R and 2-R complexes also fluoresce in the visible region under ambient condition while excited at around 400 nm. Cyclic voltammetry on these complexes shows a Rh(III)-Rh(IV) oxidation (within 0.76-1.68 vs. SCE), followed by an oxidation of the coordinated triazene ligand (except the R = NO2 complexes). An irreversible reduction of the coordinated triazene is also observed for all the complexes below −0.96 V vs. SCE. In the 1-R and 2-R complexes potential of the Rh(III)-Rh(IV) oxidation correlates linearly with the electron-withdrawing nature of the para-substituent (R).  相似文献   

15.
Three monomeric germatranes, 1-isopropoxy-3,3,7,7,10,10-hexamethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (1), 1-isopropoxy-3,3,7,7-tetramethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (2), and 1-isopropoxy-3,3-dimethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (3) have been synthesized by the reaction of Ge(O-i-Pr)4 in refluxing toluene with corresponding triethanolamines, (HOCH2CH2)nN(CH2CMe2OH)3−n (n = 0, L1H3; n = 1, L2H3; n = 2, L3H3), where the number of CMe2 groups adjacent to a OH functionality varied from 3 (L1H3) to 2 (L2H3), and to 1 (L3H3). These germatranes 1-3 have been characterized by solution 1H and 13C{1H} NMR and the solid state structure of 2 has been determined by single crystal X-ray diffraction.  相似文献   

16.
Zhaochao Xu  Jingnan Cui  Rong Zhang 《Tetrahedron》2006,62(43):10117-10122
The design, synthesis, and photophysical evaluation of a new naphthalimide-based fluorescent chemosensor, N-butyl-4-[di-(2-picolyl)amino]-5-(2-picolyl)amino-1,8-naphthalimide (1), were described for the detection of Zn2+ in aqueous acetonitrile solution at pH 7.0. Probe 1 showed absorption at 451 nm and a strong fluorescence emission at 537 nm (ΦF=0.33). The capture of Zn2+ by the receptor resulted in the deprotonation of the secondary amine conjugated to 1,8-naphthalimide so that the electron-donating ability of the N atom would be greatly enhanced; thus probe 1 showed a 56 nm red-shift in absorption (507 nm) and fluorescence spectra (593 nm, ΦF=0.14), respectively, from which one could sense Zn2+ ratiometrically and colorimetrically. The deprotonated complex, [(1-H)/Zn]+, was calculated at m/z 619.1800 and measured at m/z 618.9890. In contrast to these results, the emission of 1 was thoroughly quenched by Cu2+, Co2+, and Ni2+. The addition of other metal ions such as Li+, Na+, K+, Mg2+, Ca2+, Fe3+, Mn2+, Al3+, Cd2+, Hg2+, Ag+, and Pb2+ produced a nominal change in the optical properties of 1 due to their low affinity to probe 1. This means that probe 1 has a very high fluorescent imaging selectivity to Zn2+ among metal ions.  相似文献   

17.
Four cyclometalated Pt(II) complexes, i.e., [(L2)PtCl] (1b), [(L3)PtCl] (1c), [(L2)PtCCC6H5] (2b) and [(L3)PtCCC6H5] (2c) (HL2 = 4-[p-(N-butyl-N-phenyl)anilino]-6-phenyl-2,2′-bipyridine and HL3 = 4-[p-(N,N′-dibutyl-N′-phenyl)phenylene-diamino]-phenyl-6-phenyl-2,2′-bipyridine), have been synthesized and verified by 1H NMR, 13C NMR and X-ray crystallography. Unlike previously reported complexes [(L1)PtCl] (1a) and [(L1)PtCCC6H5] (2a) (HL1 = 4,6-diphenyl-2,2′-bipyridine), intense and continuous absorption bands in the region of 300-500 nm with strong metal-to-ligand charge transfer (1MLCT) (dπ(Pt) → π(L)) transitions (ε ∼ 2 × 104 dm3 mol−1 cm−1) at 449-467 nm were observed in the UV-Vis absorption spectra of complexes 1b, 1c, 2b and 2c. Meanwhile, with the introduction of electron-donating arylamino groups in the ligands of 1a and 2a, complexes 1b and 2b display stronger phosphorescence in CH2Cl2 solutions at room temperature with bathochromically shifted emission maxima at 595 and 600 nm, relatively higher quantum yields of 0.11 and 0.26, and much longer lifetimes of 8.4 and 4.5 μs, respectively. An electrochromic film of 1b-based polymer was obtained on Pt or ITO electrode surface, which suggests an efficient oxidative polymerization behavior. An orange multilayer organic light-emitting diode with 1b as phosphorescent dopant was fabricated, achieving a maximum current efficiency of 11.3 cd A−1 and a maximum external efficiency of 5.7%. The luminescent properties of complexes 1c and 2c are dependent on pH value and solvent polarity, which is attributed to the protonation of arylamino units in the C^N^N cyclometalating ligands.  相似文献   

18.
A click generated quinoline derivative (1) has been synthesized and used as a fluorescent probe for sequential recognition of Cu2+ and pyrophosphate (PPi) in DMSO/H2O (1:1, v/v, HEPES 20 mM, pH = 7.4) solution. Probe 1 displays high selectivity to Cu2+ ions, and the in-situ prepared probe 1-Cu2+ exhibits high selectivity toward pyrophosphate (PPi) with emission recovery of probe 1. Therefore, 1-Cu2+ complex can be applied as a fluorescence turn-on probe for PPi with high selectivity and sensitivity.  相似文献   

19.
In an effort to find simple and common single-source precursors for palladium sulfide nanostructures, palladium(II) complexes, [Pd(S2X)2] (X = COMe (1), COiPr (2)) and η3-allylpalladium complexes with xanthate ligands, [(η3-CH2C(CH3)CR2)Pd(S2X)] (R = H, X = COMe (3); R = H, X = COEt (4); R = H, X = COiPr (5); R = CH3, X = COMe (6)), have been investigated. The crystal structures of [Pd(S2X)2] (X = COMe (1), CoiPr (2)) and [(η3-CH2C(CH3)CH2)Pd(S2COMe)] (3) have been established by single crystal X-ray diffraction analysis. The complexes, 1, 2 and 3 all contain a square planar palladium(II) centre. In the allyl complex 3, this is defined by the two sulfurs of the xanthate and the outer carbons of the 2-methylallyl ligand, while in the complexes, 1 and 2 it is defined by the four sulfur atoms of the xanthate ligand. Thermogravimetric studies have been carried out to evaluate the thermal stability of η3-allylpalladium(II) analogues. The complexes are useful precursors for the growth of nanocrystals of PdS either by furnace decomposition or solvothermolysis in dioctyl ether. The solvothermal decomposition of complexes in dioctyl ether gives a new metastable phase of PdS which can be transformed to the more stable tetragonal phase at 320 °C. The nanocrystals obtained have been characterized by PXRD, SEM, TEM and EDX.  相似文献   

20.
Praseodymium ion selective polyvinyl chloride (PVC) membrane sensors, based on two new Schiff's bases 1,3-diphenylpropane-1,3-diylidenebis(azan-1-ylidene)diphenol (M1) and N,N′-bis(pyridoxylideneiminato) ethylene (M2) have been developed and studied. The sensor having membrane composition of PVC: o-NPOE: ionophore (M1): NaTPB (w/w; mg) of 150: 300: 8: 5 showed best performances in comparison to M2 based membranes. The sensor based on (M1) exhibits the working concentration range 1.0 × 10−8 to 1.0 × 10−2 M with a detection limit of 5.0 × 10−9 M and a Nernstian slope 20.0 ± 0.3 mV decade−1 of activity. It exhibited a quick response time as <8 s and its potential responses were pH independent across the range of 3.5-8.5.The influence of the membrane composition and possible interfering ions have also been investigated on the response properties of the electrode. The sensor has been found to work satisfactorily in partially non-aqueous media up to 15% (v/v) content of methanol, ethanol or acetonitrile and could be used for a period of 3 months. The selectivity coefficients determined by using fixed interference method (FIM) indicate high selectivity for praseodymium(III) ions over wide variety of other cations. To asses its analytical applicability the prepared sensor was successfully applied for determination of praseodymium(III) in spiked water samples.  相似文献   

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