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81.
82.
From Dark to Light to Fluorescence Resonance Energy Transfer (FRET): Polarity‐Sensitive Aggregation‐Induced Emission (AIE)‐Active Tetraphenylethene‐Fused BODIPY Dyes with a Very Large Pseudo‐Stokes Shift
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Esra Şen Dr. Kadem Meral Dr. Serdar Atılgan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):736-745
The work presented herein is devoted to the fabrication of large Stokes shift dyes in both organic and aqueous media by combining dark resonance energy transfer (DRET) and fluorescence resonance energy transfer (FRET) in one donor–acceptor system. In this respect, a series of donor–acceptor architectures of 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) dyes substituted by one, two, or three tetraphenylethene (TPE) luminogens were designed and synthesised. The photophysical properties of these three chromophore systems were studied to provide insight into the nature of donor–acceptor interactions in both THF and aqueous media. Because the generation of emissive TPE donor(s) is strongly polarity dependent, due to its aggregation‐induced emission (AIE) feature, one might expect the formation of appreciable fluorescence emission intensity with a very large pseudo‐Stokes shift in aqueous media when considering FRET process. Interestingly, similar results were also recorded in THF for the chromophore systems, although the TPE fragment(s) of the dyes are non‐emissive. The explanation for this photophysical behaviour lies in the DRET. This is the first report on combining two energy‐transfer processes, namely, FRET and DRET, in one polarity‐sensitive donor–acceptor pair system. The accuracy of the dark‐emissive donor property of the TPE luminogen is also presented for the first time as a new feature for AIE phenomena. 相似文献
83.
Summary The synthesis and characterization of new NiII, PdII, PtII and CoIII complexes, with the BF
inf2
sup+
-bridged,bis(-di-oximato) ligands are described. The initially formed six-coordinate hydrogen-bonded macrocycles, were used as metal templates to prepare the corresponding BF
inf2
sup+
- capped macrocycles. The complexes were characterized by1H-n.m.r. and i.r. spectroscopy, and by elemental analysis. 相似文献
84.
Dibenzo[e,k]-2,3-bis(hydroxyimino)-1,4-dithia-7,10-diaza-2,3,8,9-tetrahydrocyclododecine (H2L) has been prepared from 1,2-bis(o-mercaptoanilino) ethane ( 4 ) and (E,E)-dichloroglyoxime. A mononuclear complex with a metal: ligand ratio of 1:2 has been isolated for cobalt(III). The CoIII complex of H2L has been prepared with L′ = 2,6-lutidine, and with a chlorine ion as axial ligands. In addition to that, the synthesis of a new cobalt complex which contains BF2+ bridges is achieved with the bis(E,E)-dioxime ligand. The trinuclear complex of this CoIII complex has been obtained by the reaction of BF2+ bridged CoIII complex with Pd[bis(benzonitrile)]Cl2. The structures of these complexes and (E,E)-dioxime were identified by using elemental analysis, 1H and 13C-NMR, IR and MS spectral data. 相似文献
85.
Mononuclear [Co(HL)2LCl)], [Co(LBF2)2LCl] or [Cu-(HL)2] H2L = {N,N-bis (4-N-phenylaza [15]crown-5)diaminoglyoxime} and a trinuclear, [Cu(L)2(CuL)2](NO3)2, complex of the ligand were synthesized and characterized. The mononuclear copper(II) species coordinates to two copper(II) ions through the deprotonated oximate oxygens to yield a trinuclear structure cis-bridged by the oximate groups, with 1,10-phenanthroline as an end-cap ligand. The terminal copper adopts an essentially planar configuration with the nitrogen atoms of H2L. The structure of the ligand and its complexes is proposed and formulated according to the elemental analyses, 1H- and 13C-n.m.r, i.r. and m.s. spectral data. 相似文献
86.
Kapou A Benetis NP Durdagi S Nikolaropoulos S Mavromoustakos T 《Journal of chemical information and modeling》2008,48(11):2254-2264
Thirty-eight antileukemic steroidal esters possessing conformationally flexible nitrogen mustards were studied, and the 3D QSAR/CoMFA and CoMSIA methodologies were applied in order to derive the correlation between their structure and the in vivo antileukemic activity. These compounds show significantly reduced toxicity and possibly increased bioavailability compared to free nitrogen mustards and therefore constitute potent antileukemic drugs. Both the CoMFA and CoMSIA studies gave similar results indicating that the steric effect and the hydrophobic/hydrophilic balance especially in the steroidal part of the molecules probably determined their bioactivity. Of paramount interest is the observation that the orientation of the alkylating part of the SMEs toward the surface of ring B of the steroidal skeleton was related with increased activity. Concerning the steroidal part, the presence of hydrophobic groups in rings B and D was found to be important for enhanced activity. Enhancement of antileukemic potency is further observed if hydrophilic/H-bond acceptor groups are present at the positions 7 and 17 of the steroidal skeleton. Leapfrog simulations provided novel compounds which lead our future synthetic endeavor for obtaining SMEs with optimum bioactivity. 相似文献
87.
88.
Serbest Kerim Karaböcek Serdar Değirmencioğlu İsmail Güner Saadettin Kormali Fatma 《Transition Metal Chemistry》2001,26(4-5):375-379
A new ligand incorporating a dioxime moiety, 3-{2-[2-(2-hydroxyimino-1-methylpropylideneamino)ethylamino]ethylimino}butan-2-one oxime, (H2mdo), has been synthesized and its mono-, di- and trinuclear copper(II), and hetero-dinuclear copper(II)–manganese(II) complexes have been prepared and characterized by elemental analyses, magnetic moments, 1H- and 13C-n.m.r., i.r. and mass spectral studies. A mononuclear copper(II) complex of H2mdo was found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N); the data support the proposed structure of H2mdo and its complexes. 相似文献
89.
Serbest Kerim Değirmencioğlu İsmail Karaböcek Serdar Güner Saadettin 《Transition Metal Chemistry》2001,26(1-2):232-236
A new binucleating ligand incorporating four oxime groups, butane-2,3-dione O-[4-aminooxy-2,3-bis-(2-hydroxyimino-1-methyl-propylideneaminooxymethyl)-but-2-enyl]-dioxime, (H4mto), has been synthesized and its dinuclear cobalt(III), copper(II), and homo- and hetero-tetranuclear copper(II)–manganese(II) complexes have been prepared and characterized by 1H- and 13C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stoichiometric and spectroscopic data indicate that the metal ions in the complexes are coordinated to the oxime nitrogen atoms (C=N) and the data support the proposed structure for H4mto and its complexes. Moreover, dinuclear cobalt(III) and copper(II) complexes of H4mto have a 2:1 metal:ligand ratio. 相似文献
90.
The constitutive theories intended to quantitatively account for the complicated material response exhibited by polymers include, in general, adjustable material parameters. These must be identified from experimental data obtained from the material under consideration. This contribution presents the complete procedure studying the behavior of polymers at large strains in three basic steps: i) Accomplishment of homogeneous and 3-D inhomogeneous experiments under different deformation conditions. ii) Identification of the material parameters of a constitutive model by means of gradient–based optimization methods with respect to the homogeneous experimental data. iii) Validation of the identified material parameters by comparing 3-D FE simulations to the inhomogeneous experimental data. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献