Methoxy-substituted isoTQEN family for enhanced fluorescence response toward zinc ion

Previously, we have reported that 1- and 3-isoTQENs (N,N,N',N'-tetrakis(1- or 3-isoquinolylmethyl)ethylenediamines) exhibit a specific fluorescence enhancement toward zinc ion. In this study, three methoxy-substituted derivatives of 1-isoTQEN were synthesized and their fluorescent response toward zinc ion was studied. The substitution pattern of the methoxy group significantly changes the solubility of compounds in aqueous DMF, λ(max) in the absorption spectra, excitation/emission wavelengths and fluorescence intensity of zinc complexes. In the presence of zinc ion, 7-MeO-1-isoTQEN exhibits higher fluorescence intensity and longer excitation/emission wavelengths (λ(ex) = 342 nm, λ(em) = 526 nm) than 6-MeO-1-isoTQEN (λ(ex) = 303 nm, λ(em) = 469 nm) and 5,6,7-triMeO-1-isoTQEN (λ(ex) = 340 nm, λ(em) = 504 nm). The fluorescence intensity of a zinc complex of 7-MeO-1-isoTQEN (? = 0.122) is four times higher than the parent 1-isoTQEN (? = 0.034) under the same conditions. The crystal structure of 7-MeO-1-isoTQEN-Zn complex reveals that all six nitrogen atoms participate to the metal coordination with ideal octahedral geometry, affording significantly high metal binding affinity comparable with TPEN (N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine). 7-MeO-1-isoTQEN detects zinc ion concentration change in cells by fluorescence microscopic analysis.     

Tetrakis(2-quinolinylmethyl)ethylenediamine (TQEN) as a new fluorescent sensor for zinc

A new fluorescent sensor for zinc that binds 1 equivalent of zinc ion, N,N,N',N'-tetrakis(2-quinolylmethyl)ethylenediamine (TQEN), has been prepared and characterized. Zinc-bound TQEN exhibits fluorescence around 383 nm upon excitation at 317 nm, while free TQEN emits very weak fluorescence. UV-Vis and 1H NMR spectral changes also detected the binding of TQEN with zinc ion. The crystal structure of zinc complex with TQEN was determined by X-ray crystallography and compared with that of the TPEN-Zn complex (TPEN =N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine). The binding affinity of TQEN with zinc ion is very high (Kd < 1 microM in aqueous dmf solution). Competition experiments reveal that the zinc-binding affinity of TQEN is lower than the parent, strong metal ion chelator TPEN, and comparable to EGTA (EGTA = ethylene glycol-bis(2-aminomethyl)-N,N,N',N'-tetraacetic acid).     

Ultrafast excited-state dynamics of rhenium(I) photosensitizers [Re(Cl)(CO)3(N,N)] and [Re(imidazole)(CO)3(N,N)]+: diimine effects

Femto- to picosecond excited-state dynamics of the complexes [Re(L)(CO)(3)(N,N)](n) (N,N = bpy, phen, 4,7-dimethyl-phen (dmp); L = Cl, n = 0; L = imidazole, n = 1+) were investigated using fluorescence up-conversion, transient absorption in the 650-285 nm range (using broad-band UV probe pulses around 300 nm) and picosecond time-resolved IR (TRIR) spectroscopy in the region of CO stretching vibrations. Optically populated singlet charge-transfer (CT) state(s) undergo femtosecond intersystem crossing to at least two hot triplet states with a rate that is faster in Cl (～100 fs)(-1) than in imidazole (～150 fs)(-1) complexes but essentially independent of the N,N ligand. TRIR spectra indicate the presence of two long-lived triplet states that are populated simultaneously and equilibrate in a few picoseconds. The minor state accounts for less than 20% of the relaxed excited population. UV-vis transient spectra were assigned using open-shell time-dependent density functional theory calculations on the lowest triplet CT state. Visible excited-state absorption originates mostly from mixed L;N,N(?-) → Re(II) ligand-to-metal CT transitions. Excited bpy complexes show the characteristic sharp near-UV band (Cl, 373 nm; imH, 365 nm) due to two predominantly ππ*(bpy(?-)) transitions. For phen and dmp, the UV excited-state absorption occurs at ～305 nm, originating from a series of mixed ππ* and Re → CO;N,N(?-) MLCT transitions. UV-vis transient absorption features exhibit small intensity- and band-shape changes occurring with several lifetimes in the 1-5 ps range, while TRIR bands show small intensity changes (≤5 ps) and shifts (～1 and 6-10 ps) to higher wavenumbers. These spectral changes are attributable to convoluted electronic and vibrational relaxation steps and equilibration between the two lowest triplets. Still slower changes (≥15 ps), manifested mostly by the excited-state UV band, probably involve local-solvent restructuring. Implications of the observed excited-state behavior for the development and use of Re-based sensitizers and probes are discussed.     

The new fluorescence enhancement system Tb-N-(2-pyridinyl) ketoacetamide-Et(3)N-Zn and its application

A sensitive fluorescence enhancement system was developed for the determination of terbium. The fluorescence intensity of the Tb-N-(2-pyridinyl) ketoacetamide (PKAA) system was greatly enhanced by the addition of triethylamine (Et(3)N) and zinc nitrate in the methanol solution. The excitation and emission wavelengths were 329 and 546 nm, respectively. Under optimal conditions, the fluorescence intensities varied linearly with the concentration of Tb(3+) in the range of 7.5 x 10(-8)-8.2 x 10(-6)M with a detection limit of 6.4 x 10(-8)M. The interferences of some rare earth ions were described. This method was applied to the determination of trace amounts of terbium (III) in a synthetic rare earth oxide and a high purity Y(2)O(3) matrix. The mechanism of fluorescence enhancement was also studied.     

Spectrophotometric determination of chromium(VI) through ion-pair formation with phenylfluorone

Two successive outer sphere complexes with mole ratios of 1:1 and 1:2 are formed between chromium(VI) and phenylfluorone at pH 1.5 in 40% ethanol. These have absorption maxima at 490 and 470 nm, respectively. The 1:1 complex obeys Beer's law at 500 nm (? = 2.1 × 10⁴ 1 mol^-1 cm^-1) in the range 13–1700 ng l^-1 chromium(VI).     

新型荧光试剂1-(8-喹啉)-3-(3,5-二溴-2-吡啶)-三氮烯的合成及其应用

将具有荧光特性的杂环8-氨基喹啉和吡啶类试剂结合,并引入三氮烯结构,合成了新型荧光试剂1-(8-喹啉)-3-(3,5-二溴-2-吡啶)-三氮烯(QBPyT)。其结构经元素分析、红外光谱、核磁共振波谱证实。研究结果表明,在pH 9.5硼酸-氢氧化钠缓冲溶液的介质存在下,该试剂在λex/λem=248nm/496nm处产生强荧光,并且能与铅(Ⅱ)形成配合物从而使荧光增强。据此建立了三氮烯测定铅(Ⅱ)的新型荧光分析法。铅的浓度在5.0×10-7～1.2×10-5 mol.L范围内与其荧光强度呈线性关系,检出限(3S/N)为9.5×10-8 mol.L。将其应用于水样中铅(Ⅱ)的测定,测得回收率在92.6%～94.0%之间,测定值的相对标准偏差(n=5)小于3.5%。     

TSQ (6-methoxy-8-p-toluenesulfonamido-quinoline), a common fluorescent sensor for cellular zinc, images zinc proteins

Zn(2+) is a necessary cofactor for thousands of mammalian proteins. Research has suggested that transient fluxes of cellular Zn(2+) are also involved in processes such as apoptosis. Observations of Zn(2+) trafficking have been collected using Zn(2+) responsive fluorescent dyes. A commonly used Zn(2+) fluorophore is 6-methoxy-8-p-toluenesulfonamido-quinoline (TSQ). The chemical species responsible for TSQ's observed fluorescence in resting or activated cells have not been characterized. Parallel fluorescence microscopy and spectrofluorometry of LLC-PK(1) cells incubated with TSQ demonstrated punctate staining that concentrated around the nucleus and was characterized by an emission maximum near 470 nm. Addition of cell permeable Zn-pyrithione resulted in greatly increased, diffuse fluorescence that shifted the emission peak to 490 nm, indicative of the formation of Zn(TSQ)(2). TPEN (N,N,N'N'-tetrakis(-)[2-pyridylmethyl]-ethylenediamine), a cell permeant Zn(2+) chelator, largely quenched TSQ fluorescence returning the residual fluorescence to the 470 nm emission maximum. Gel filtration chromatography of cell supernatant from LLC-PK(1) cells treated with TSQ revealed that TSQ fluorescence (470 nm emission) eluted with the proteome fractions. Similarly, addition of TSQ to proteome prior to chromatography resulted in 470 nm fluorescence emission that was not observed in smaller molecular weight fractions. It is hypothesized that Zn-TSQ fluorescence, blue-shifted from the 490 nm emission maximum of Zn(TSQ)(2), results from ternary complex, TSQ-Zn-protein formation. As an example, Zn-carbonic anhydrase formed a ternary adduct with TSQ characterized by a fluorescence emission maximum of 470 nm and a dissociation constant of 1.55 × 10(-7) M. Quantification of TSQ-Zn-proteome fluorescence indicated that approximately 8% of cellular Zn(2+) was imaged by TSQ. These results were generalized to other cell types and model Zn-proteins.     

Nickel(II)-induced excimer formation of a naphthalene-based fluorescent probe for living cell imaging

Ni(2+)-induced intramolecular excimer formation of a naphthalene-based novel fluorescent probe, 1-[(naphthalen-3-yl)methylthio]-2-[(naphthalen-6-yl)methylthio]ethane (L), has been investigated for the first time and nicely demonstrated by excitation spectra, a fluorescence lifetime experiment, and (1)H NMR titration. The addition of Ni(2+) to a solution of L (DMSO:water = 1:1, v/v; λ(em) = 345 nm, λ(ex) = 280 nm) quenched its monomer emission, with subsequent enhancement of the excimer intensity (at 430 nm) with an isoemissive point at 381 nm. The fluorescence lifetime of free L (0.3912 ns) is much lower than that of the nickel(2+) complex (1.1329 ns). L could detect Ni(2+) as low as 1 × 10(-6) M with a fairly strong binding constant, 2.0 × 10(4) M(-1). Ni(2+)-contaminated living cells of plant origin could be imaged using a fluorescence microscope.     

cis-Dicyanoosmium(II) diimine complexes bearing phosphine or sulfoxide ligands: spectroscopic and luminescent studies

A series of cis-dicyanoosmium(II) complexes [Os(PPh3)2(CN)2(N intersectionN)] (N intersectionN = Ph2phen (2a), bpy (2b), phen (2c), Ph2bpy (2d), tBu2bpy (2e)) and [Os(DMSO)2(CN)2(N intersectionN)] (3a-3e, N intersectionN = Br2phen (3f), Clphen (3g)), were synthesized and their spectroscopic and photophysical properties were examined, and [Os(PMe3)2(CN)2(phen)] (4) with axial PMe3 ligands was similarly prepared. The molecular structures of 2a, 2c, [2c.Zn(NO3)2]infinity, 2d, 2e, 3b, 3d, 3e, and 4 were determined by X-ray crystallographic analyses. The two CN ligands are cis to each other with mean Os-C bond distance of 2.0 A. The two PR3 (R = Ph, Me) or DMSO ligands are trans to each other with P/S-Os-P/S angles of approximately 177 degrees . The UV-vis absorption spectra of 2a-2e display an intense absorption band at 268-315 nm (epsilon = approximately (1.54-4.82) x 104 M-1 cm-1) that are attributed to pi --> pi*(N intersection N) and/or pi --> pi*(PPh3) transitions. The moderately intense absorption bands with lambdamax at 387-460 nm (epsilon = approximately (2.4-11.3) x 103 M(-1) cm(-1)) are attributed to a 1MLCT transition. A weak, broad absorption at 487-600 nm (epsilon = approximately 390-1900 M(-1) cm(-1)) is assigned to a 3MLCT transition. Excitation of 2a-2e in dichloromethane at 420 nm gives an emission with peak maximum at 654-703 nm and lifetime of 0.16-0.67 micros. The emission energies, lifetimes, and quantum yields show solvatochromic responses, and plots of numax, tau, and Phi, respectively, versus ET (solvent polarity parameter) show linear correlations, indicating that the emission is sensitive to the local environment. The broad structureless solid-state emission of 2a-2e at 298 (lambdamax 622-707 nm) and 77 (lambdamax 602-675 nm) K are assigned to 3MLCT excited states. The 77 K MeOH/EtOH (1:4) glassy solutions of 2a-2e also exhibit 3MLCT emissions with lambdamax = 560-585 nm. The 1MLCT absorption and 3MLCT emission of 3a-3g occur at lambdamax = 332-390 nm and 553-644 nm, respectively. In the presence of Zn(NO3)2, both the 1MLCT absorption and 3MLCT emission of 2c in acetonitrile blue-shift from 397 to 341 nm and 651 to 531 nm, respectively. The enhancement of emission intensity (I/Io) of 2e at 531 nm reached a maximum of approximately 810 upon the addition of two equivs of Zn(NO3)2. The crystallographic and spectroscopic evidence suggests that 2c undergoes binding of Zn2+ ions via the cyano moieties.     

Synthesis and characterization of luminescent zinc(II) and cadmium(II) complexes with N,S-chelating Schiff base ligands

The reactions of zinc(II) acetate with a variety of 2-substituted benzothiazolines afforded tetrahedral mononuclear complexes with a N 2S 2 donor set, [Zn(RPhC(H) NC 6H 4 S) 2]. The obtained zinc(II) complexes can be divided into three groups based on the characteristics of the absorption spectra; Group 1 (R = 2,4,6-triMe ( 1), 2,6-diCl ( 2)) showing an intense band at 250-300 nm and a weak band at 400-450 nm, Group 2 (R = 4-Cl ( 3), H ( 4), 4-Et ( 5), 4-OMe ( 6)) showing two intense bands at 250-300 nm and a weak band at 400-450 nm, and Group 3 (R = 4-NMe 2 ( 7), 4-NEt 2 ( 8)) showing an intense band at 250-300 nm and two very intense bands at 350-450 nm. The Group 2 and Group 3 complexes exhibited a strong emission on irradiating with ultraviolet light while the Group 1 complexes were not emissive at room temperature. However, all the zinc(II) complexes were luminescent in CH 2Cl 2/toluene glass at 77 K, and their emission peak energies were found to correlate with the Hammett constant of the substituent at para position of a pendent phenyl ring in each complex. Similar reactions of cadmium(II) acetate with 2-substituted benzothiazolines were also carried out to synthesize corresponding cadmium(II) complexes. While [Cd(RPhC(H) NC 6H 4 S) 2] (R = 2,4,6-triMe ( 9)) with bulky substituents at ortho positions of a pendent phenyl ring had a tetrahedral mononuclear structure, other cadmium(II) complexes [Cd 2(RPhC(H) NC 6H 4 S) 4] (R = 4-Et ( 10), 4-OMe ( 11), 4-NMe 2 ( 12)) possessed S-bridged dinuclear structures. These cadmium(II) complexes, which are assumed to have a mononuclear structure in solution, showed photophysical properties similar to those of the corresponding zinc(II) complexes.     

Luminescent cyclometalated platinum(II) complexes with amino acid ligands for protein binding

Pt(C/N)(phe)(1, C/N = 2-(2'-thienyl)pyridine, phe = phenylalanine) shows a high binding affinity (ca. 10(6) dm(3) mol(-1)) and selectivity towards human serum albumin (HSA) and such binding is accompanied by an enhancement of photoluminescence at 562 nm; both the protein binding affinity and cytotoxicities of [Pt(C/N)(phe)(1), Pt(C/N)(trp)(2, trp = tryptophan) and Pt(C/N)(gly)(3, gly = glycine)] are affected by the amino acid ligand with having an IC(50) of up to 1 microM against a number of carcinoma cell lines.     

A new zinc(II) fluorophore 2-(9-anthrylmethylamino)ethyl-appended 1,4,7,10-tetraazacyclododecane

A new 2-(9-anthrylmethylamino)ethyl-appended cyclen, L(3) (1-(2-(9-anthrylmethylamino)ethyl)-1,4,7,10-tetraazacyclododecane) (cyclen = 1,4,7,10-tetraazacyclododecane), was synthesized and characterized for a new Zn(2+) chelation-enhanced fluorophore, in comparison with previously reported 9-anthrylmethylcyclen L(1) (1-(9-anthrylmethyl)-1,4,7,10-tetraazacyclododecane) and dansylamide cyclen L(2). L(3) showed protonation constants log K(a)(i)() of 10.57 +/- 0.02, 9.10 +/- 0.02, 7.15 +/- 0.02, <2, and <2. The log K(a3) value of 7.15 was assigned to the pendant 2-(9-anthrylmethylamino)ethyl on the basis of the pH-dependent (1)H NMR and fluorescence spectroscopic measurements. The potentiometric pH titration study indicated extremely stable 1:1 Zn(2+)-L(3) complexation with a stability constant log K(s)(ZnL(3)) (where K(s)(ZnL(3)) = [ZnL(3)]/[Zn(2+)][L(3)] (M(-)(1))) of 17.6 at 25 degrees C with I = 0.1 (NaNO(3)), which is translated into the much smaller apparent dissociation constant K(d) (=[Zn(2+)](free)[L(3)](free)/[ZnL(3)]) of 2 x 10(-)(11) M with respect to 5 x 10(-)(8) M for L(1) at pH 7.4. The quantum yield (Phi = 0.14) in the fluorescent emission of L(3) increased to Phi = 0.44 upon complexation with zinc(II) ion at pH 7.4 (excitation at 368 nm). The fluorescence of 5 microM L(3) at pH 7.4 linearly increased with a 0.1-5 microM concentration of zinc(II). By comparison, the fluorescent emission of the free ligand L(1) decreased upon binding to Zn(2+) (from Phi = 0.27 to Phi = 0.19) at pH 7.4 (excitation at 368 nm). The Zn(2+) complexation with L(3) occurred more rapidly (the second-order rate constant k(2) is 4.6 x 10(2) M(-)(1) s(-)(1)) at pH 7.4 than that with L(1) (k(2) = 5.6 x 10 M(-)(1) s(-)(1)) and L(2) (k(2) = 1.4 x 10(2) M(-)(1) s(-)(1)). With an additionally inserted ethylamine in the pendant group, the macrocyclic ligand L(3) is a more effective and practical zinc(II) fluorophore than L(1).     

Spectroscopic studies and structures of trans-ruthenium(II) and ruthenium(III) bis(cyanide) complexes supported by a tetradentate macrocyclic tertiary amine ligand

trans-[Ru(16-TMC)(C[triple bond]N)2] (1; 16-TMC = 1,5,9,13-tetramethyl-1,5,9,13-tetraazacyclohexadecane) was prepared by the reaction of trans-[Ru(16-TMC)Cl2]Cl with KCN in the presence of zinc powder. The oxidation of 1 with bromine gave trans-[Ru(16-TMC)(CN)2]+ isolated as PF6 salt (2.PF6). The Ru-C/C-N distances are 2.061(4)/1.130(5) and 2.069(5)/1.140(7) A for 1 and 2, respectively. Both complexes show a Ru(III/II) couple at 0.10 V versus FeCp2+/0. The UV-vis absorption spectrum of 1 is dominated by an intense high-energy absorption at lambda(max) = 230 nm, which is mainly originated from dpi(RuII) --> pi*(N[triple bond]C-Ru-C[triple bond]N) charge-transfer transition. Complex 2 shows intense absorption bands at lambda(max) pi*(N[triple bond]C-Ru-C[triple bond]N) and sigma(-CN) --> d(RuIII) charge-transfer transition, respectively. Density functional theory and time-dependent density-functional theory calculations have been performed on trans-[(NH3)4Ru(C[triple bond]N)2] (1') and trans-[(NH3)4Ru(C[triple bond]N)2]+ (2') to examine the Ru-cyanide interaction and the nature of associated electronic transition(s). The 230 nm band of 1 has been probed by resonance Raman spectroscopy. Simulations of the absorption band and the resonance Raman intensities show that the nominal nuC[triple bond]N stretch mode accounts for ca. 66% of the total vibrational reorganization energy. A change of nominal bond order for the cyanide ligand from 3 to 2.5 is estimated upon the electronic excitation.     

Platinum(II) complexes with pi-conjugated, naphthyl-substituted, cyclometalated ligands (RC N N): structures and photo- and electroluminescence

The crystal structures and photophysical properties of mononuclear [(RC N N)PtX](ClO4)n ((RC N N)=3-(6'-(2'-naphthyl)-2'-pyridyl)isoquinolinyl and derivatives; X=Cl, n=0; X=PPh(3) or PCy(3), n=1), dinuclear [(RC N N)2Pt2(mu-dppm)](ClO4)2 (dppm=bis(diphenyphosphino)methyl) and trinuclear [(RC N N)3Pt3(mu-dpmp)](ClO4)3 (dpmp=bis(diphenylphosphinomethyl)phenylphosphine) complexes are presented. The crystal structures show extensive intra- and/or intermolecular pipi interactions; the two (RC N N) planes of [(RC N N)2Pt2(mu-dppm)](ClO4)2 (R=Ph, 3,5-tBu2Ph or 3,5-(CF3)2Ph) are in a nearly eclipsed configuration with torsion angles close to 0 degrees. [(RC N N)PtCl], [(RC N N)2Pt2(mu-dppm)](ClO4)2, and [(RC N N)3Pt3(mu-dpmp)](ClO4)3 are strongly emissive with quantum yields of up to 0.68 in CH2Cl2 or MeCN solution at room temperature. The [(RC N N)PtCl] complexes have a high thermal stability (T(d)=470-549 degrees C). High-performance light-emitting devices containing [(RC N N)PtCl] (R=H or 3,5-tBu2Ph) as a light-emitting material have been fabricated; they have a maximum luminance of 63,000 cd m(-2) and CIE 1931 coordinates at x=0.36, y=0.54.     

基于一维[H_2Mo_4O_(14)]_n~(2n-)链和双吡啶双酰胺配体的三维锌配合物的合成、结构与性能

选择柔性的双吡啶双酰胺配体N,N'-双(3-吡啶甲酰胺基)-1,2-乙烷(3-bpye)、钼酸铵和氯化锌在水热条件下自组装制备了一个基于一维[H_2Mo_4O_(14)]_n~(2n-)链的三维锌配合物[Zn(3-bpye)(H_2Mo_4O_(14))(H_2O)_2],并通过元素分析、红外光谱、热重分析等技术手段研究了配合物的结构,并利用X射线单晶衍射分析进行了晶体结构表征。结构解析揭示标题配合物是三斜晶系,P-1空间群,晶胞参数a=0.61310(3)nm,b=1.04750(6)nm,c=1.06540(6)nm,α=78.5540(10)°,β=77.5350(10)°,γ=89.9050(10)°,V=0.65420(6)nm~3,M_r=981.47,D_c=2.491 g/cm~3,Z=1,F(000)=468,R_1=0.0290,ωR_2=0.1068。标题配合物中,金属锌离子连接一维[H_2Mo_4O_(14)]_n~(2n-)链形成一种二维无机双金属层[Zn(H_2Mo_4O_(14))]_n,相邻的层间又通过双齿配体3-bpye连接形成三维CdSO_4拓扑的骨架结构。配合物表现出强的荧光发射特性,而且其在紫外光照下对亚甲基蓝和罗丹明B均有明显的催化降解活性。     

Determination of trace terbium(III) with N, N', N"-tri(3-indolemethanal)triaminotriethylamine based on a new fluorescence enhancement system.

A new Schiff-base ligand with a tripodal structure, N,N',N"-tri(3-indolemethanal)triaminotriethylamine (TTAIM), was synthesized. Its fluorescence intensity with terbium(III) was increased by about two orders of magnitude in the present of sodium acetate (NaAc). After the adding of the organic solvent dimethyl sulfoxide (DMSO) to the above system, leading to Tb3+ the fluorescence was further enhanced by about 16 fold. The spectrofluorimetric determination of a trace amount of Tb3+ based on this phenomenon was carried out. The excitation and emission wavelengths were 330 nm and 545 nm, respectively. Under the optimal conditions, the fluorescence intensities varied linearly with the concentration of Tb3+ in the range of 5.7 x 10(-11) - 6.3 x 10(-6) mol L(-1) with a detection limit of 5.0 x 10(-11) mol L(-1). The interferences of some rare earth metals and other inorganic ions were described. The method is a selective, sensitive, rapid and simple analytical procedure for the determination of terbium(III) in a high-purity yttrium oxide and synthetic sample. The mechanism for the fluorescence enhancement was also studied.     

荧光探针5-羰基咪唑苯并吖啶酮的合成及其LC-APCI-MS法测定胺

在不加任何催化剂条件下, 2-(12-苯并吖啶酮)-乙酸(BAAA)与N,N′-羰基双咪唑(CDI)缩合生成新型荧光探针5-羰基咪唑苯并吖啶酮(IEBA). IEBA在DMF溶剂中与胺类化合物形成的酰胺类衍生物不仅可发出强烈的荧光, 还具有较高的质谱离子化能力. 该衍生物在乙腈和甲醇-水溶液中的百分离子化δ值分别在0~57.32% 和0~62.14%范围内. 最大激发和发射波长λex/λem=272 nm/505 nm. 12种胺类衍生物的荧光检出限范围为0.15~0.50 ng/mL, 在线APCI-MS检出限范围为1.43~8.51 ng/mL.     

六(3,3-二甲基-1-(1H-1,2,4-三唑)-2-丁酮)锌高氯酸盐配合物的合成及晶体结构

3，3-二甲基-1－（1H－1，2，4-三唑）－2-丁酮的锌配合物（C48H78Cl2N18O14Zn）已被合成。X-射线衍射结构分析表明，晶体属单斜晶系，空间群P21／n，晶体学数据：晶体体积结构偏离因子，标题配合物分子中6个三唑环上的4位N原子与Zn原子配位，形成八面体结构，锌原子处在结晶学的对称中心上。     

High-performance blue electroluminescent devices based on 2-(4-biphenylyl)-5-(4-carbazole-9-yl)phenyl-1,3,4-oxadiazole

An electron transporting moiety (1,3,4-oxadiazole) and a hole transporting moiety (carbazole) were combined to create 2-(4-biphenylyl)-5-(4-carbazole-9-yl)phenyl-1,3,4-oxadiazole (CzOxa), a three layer device with a configuration of ITO/TPD(50 nm)/CzOxa(40 nm)/AlQ(40 nm)/Mg0.9Ag0.1(200 nm)/Ag(80 nm) which exhibited a blue emission peak at approximately 470 nm (x = 0.14, y = 0.19) with a maximum luminance of 26,200 cd m(-2) at a drive voltage of 15 V and a maximum luminous efficiency of 2.25 lm W(-1).     

Coumarinyl(thienyl)thiazoles: novel photochromes with modulated fluorescence

Novel photochromic 5-(3'-coumarinyl)-4-(3'-thienyl)thiazoles have been synthesized. These compounds display intensive fluorescence emission in the open form A, which is modulated by light. Fluorescence intensity decreases significantly upon irradiation of A with UV-light (lambda<400 nm) due to formation of the cyclic form B. Irradiation of B with visible light (lambda>470 nm) promotes its opening and the recovering of fluorescence. Novel dihetarylethenes undergo photochromic modulation of fluorescence both in solution and in polymeric matrices.