Sensitization of fluorescence of dye molecules in nanoparticles of metal complexes

We studied the dependence of absorption and fluorescence spectra of complexes of Al, In, Sc, Y, and La with dibenzoylmethane and naphthoyltrifluoroacetone, as well as the dependence of sensitized fluorescence of dyes in nanoparticles of these complexes, in relation to the water pH, the ratio between ions and diketones, and the ion selection. We showed that the ability of complexes of ions to form nanoparticles that efficiently sensitize dye molecules incorporated into them is determined by stability constants of these ions with organic ligands and by their ability to compete with the formation of hydroxy complexes of these ions. We found that nanoparticles consist of diketonates of different compositions and that Nile red incorporated into nanoparticles is an indicator of the dependence of the composition of nanoparticles on the selection of the central ion of complexes and conditions of their formation. We revealed that complexes M(diketone)(OH)₂ self-assemble into nanoparticles with an admixture of dye molecules and efficiently sensitize dyes upon excitation into absorption bands of complexes. We showed that, at concentrations of rhodamine 6G in water smaller than 50 nM, the use of a solution that contains 50 μM of Al(III), In(III), or Sc(III) + 50 μM of naphthoyltrifluoroacetone makes it possible to increase the sensitivity of the luminescence analysis by 20-fold for the presence of rhodamine 6G in an aqueous solution.     

The mutual influence of two different dyes on their sensitized fluorescence (cofluorescence) in nanoparticles from complexes

We have studied the fluorescence sensitization and quenching for pairs of different dyes simultaneously incorporated into nanoparticles from complexes M(diketone)₃phen, where M(III) is La(III), Lu(III), or Sc(III); diketone is p-phenylbenzoyltrifluoroacetone (PhBTA) or naphthoyltrifluoroacetone (NTA); and phen is 1,10-phenanthroline. We have shown that, upon formation of nanoparticles in the solution in the presence of two dyes the concentrations of which are either comparable with or lower than the concentration of nanoparticles (<20 nM), the intensities of the sensitized fluorescence of dyes in nanoparticles in binary solutions and in solutions of either of the dyes coincide. We have found that the intensity of sensitized fluorescence of small (<20 nM) concentrations of rhodamine 6G (R6G) or Nile blue (NB) increases by an order of magnitude upon simultaneous introduction into nanoparticles of 1 μM of coumarin 30 (C30), while the intensity of fluorescence of C30 sensitized by complexes decreases by an order of magnitude. The same effect is observed as 1 μM of R6G are introduced into nanoparticles with NB ([NB] ≤ 20 nM). The increase in the fluorescence of dye molecules upon their incorporation from the solution into nanoparticles from complexes is noticeably lower than that expected from the proposed ratio of concentrations of complexes and dyes in nanoparticles. Analysis of the obtained data indicates that the introduction of large concentrations of C30 or R6G dyes into nanoparticles makes it possible to prevent large energy losses due to impurities or upon transition to a triplet state that arises during the migration of the excitation energy over S ₁ levels of complexes. Energy accumulated by these dyes is efficiently transferred to another dye that is present in the solution at lower concentrations and that has a lower-lying S ₁ level, which makes it possible to increase its fluorescence by an order of magnitude upon its incorporation into nanoparticles.     

Particular features of manifestation of energy migration toward impurity in nanoparticles of metal complexes

We measure the fluorescence quantum yields (q _fl) of complexes of Al, Sc, Y, In, Lu, and Gd with dibenzoylmethane in aqueous and isopropanol solutions at different concentration ratios of ions and dike-tone. We reveal that, for the examined solutions, qfl of complexes varies more than by two orders of magnitude under the influence of the heavy atom. It is found that a considerable decrease in q _fl and τ_fl of ligands of complexes of listed ions caused by the influence of heavy atoms weakly affects the intensity of sensitized fluorescence of Nile red and rhodamine 6G molecules introduced into nanoparticles from these complexes in aqueous solutions. The revealed result is explained by the comparability of the singlet exciton free path length and the dimension of nanoparticles under study. We show that a lower fluorescence intensity of heavy metal complexes makes it possible to decrease its contribution in the range of the cofluorescence maximum of rhodamine 6G and to monitor the occurrence of the dye in the aqueous solution down to the concentration of 0.05 nM. We show that, in nanoparticles from Eu complexes, further fluorescence quenching of dibenzoylmethane is observed, as well as the appearance of cofluorescence of rhodamine 6G, the intensity of which is comparable with its intensity in nanoparticles of other complexes. The appearance of this cofluorescence cannot be explained by the existence of S-S energy migration.     

Columinescence of dye molecules in nanostructures of metal ion complexes

The mechanism of columinescence (fluorescence sensitization) of dyes incorporated in nanostructures of metal complexes is studied. It is shown for the first time that the columinescence of dyes is due to the transfer of excitation energy from ligands and metal ions of complexes that form nanostructures. It is proven that the dye columinescence of rhodamine 6G (R6G) molecules incorporated into nanostructures of Al(DBM)₃phen, Al(DBM) _n (OH)_{6 ? 2n} , and Eu(DBM)₃phen (DBM is dibenzoylmethane) nanostructures is completely determined by the singlet excitation energy migration from ligands to R6G molecules. It is shown that, at small concentrations of R6G, the R6G columinescence intensity is lower in nanostructures of metal complexes with a high probability of S-T conversion and that this difference disappears at large concentrations of R6G. In the case of Nile blue (whose S ₁ level lies below the ⁵ D ₀ level of Eu(III)) incorporated in nanostructures of Eu(DBM)₃phen complexes, as well as in nanostructures of Al(DBM)₃phen and Gd(DBM)₃phen complexes with admixture of Eu complexes, we observed the S-S energy transfer from DBM to NB in addition to the delayed sensitized fluorescence of NB previously observed in nanostructures of Eu complexes, which was caused by the energy transfer from the ⁵ D ₀ level of Eu(III) to NB. At dye concentrations below 100 nM, the efficiency of NB sensitization due to the migration of singlet excitation energy from DBM is lower than in the case of the energy transfer from Eu(III) ions, while, at large concentrations of the dye, the S-S energy transfer successfully competes with the sensitization of NB by Eu(III) ions. The use of dye columinescence makes it possible to easily determine dye concentrations of 2–100 nM in solutions with standard spectrofluorimeters.     

Particular features of incorporation of coumarin 30 into nanoparticles from metal complexes and the intensity of its columinescence

We have studied the sensitized fluorescence of coumarin 30 incorporated into nanoparticles from complexes of p-phenylbenzoyltrifluoroacetone and 1,10-phenanthroline with Y, La, Lu, Gd, Al, and Sc ions in 10% alcoholic-aqueous solutions. We have shown that, upon formation of nanoparticles from complexes of Y(III) and Ln(III) ions, coumarin 30 molecules are completely incorporated from the solution into nanoparticles from complexes up to dye concentrations in the solution comparable with the concentration complexes. For the nanoparticles under study, in the whole range of the examined dye concentrations, concentration quenching of the coumarin 30 cofluorescence has not been observed. Our results show that coumarin 30 is incorporated into lanthanide and yttrium complexes as a synergistic bidentate ligand. The possibility of creating brightly luminescent markers that absorb not only in the range of 360?C370 nm, but also in the range of 440?C450 nm, and have a narrow fluorescence spectrum with ??_max = 520 nm has been demonstrated.     

Sensitive Spectroscopic Detection of Large and Denatured Protein Aggregates in Solution by Use of the Fluorescent Dye Nile Red

The fluorescent dye Nile red was used as a probe for the sensitive detection of large, denatured aggregates of the model protein β-galactosidase (E. coli) in solution. Aggregates were formed by irreversible heat denaturation of β-galactosidase below and above the protein’s unfolding temperature of 57.4°C, and the presence of aggregates in heated solutions was confirmed by static light scattering. Interaction of Nile red with β-galactosidase aggregates led to a shift of the emission maximum (λ _max) from 660 to 611 nm, and to an increase of fluorescence intensity. Time-resolved fluorescence and fluorescence correlation spectroscopy (FCS) measurements showed that Nile red detected large aggregates with hydrodynamic radii around 130 nm. By steady-state fluorescence measurements, it was possible to detect 1 nM of denatured and aggregated β-galactosidase in solution. The comparison with size exclusion chromatography (SEC) showed that native β-galactosidase and small aggregates thereof had no substantial effect on the fluorescence of Nile red. Large aggregates were not detected by SEC, because they were excluded from the column. The results with β-galactosidase demonstrate the potential of Nile red for developing complementary analytical methods that overcome the size limitations of SEC, and can detect the formation of large protein aggregates at early stages.     

Influence of complexing ion on the fluorescence sensitization efficiency for oxazine dyes in nanoparticles of Sc,Eu, Sm,and Lu diketonates

The fluorescence sensitization regularities have been investigated for oxazine dyes (Nile blue, cresyl violet (oxazine-9), and oxazine-170) in nanoparticles of complexes of 2-naphthoyltrifluoroacetone with trivalent ions of rare-earth metals. The fluorescence sensitization efficiencies of dyes in nanoparticles from the Sc(III), Eu(III), Sm(III), and Lu(III) complexes are compared. It is shown that the fluorescence sensitization efficiencies of dyes in nanoparticles from the Sc(III), Eu(III), and Sm(III) complexes has similar values and greatly exceed that for nanoparticles from the Lu(III) complexes. The quantum yields of sensitized fluorescence are determined for dyes in nanoparticles from the Sc(III), Eu(III), and Sm(III) complexes. The nanoparticles doped with oxazine-170 from Eu(III) complexes are found to have the strongest fluorescence.     

A europium(III) organic ternary complex applied in fabrication of?near UV-based white light-emitting diodes

A β-diketone, 2-acetylfluorene-4,4,4-trifluorobutane-1,3-dione (HAFTFBD), and its three europium(III) complexes, Eu(AFTFBD)₃⋅2H₂O, Eu(AFTFBD)₃(TPPO)₂ and Eu(AFTFBD)₃phen, were designed and synthesized, where TPPO was triphenylphosphine oxide and phen was 1,10-phenanthroline. The complexes were characterized by IR, UV-visible, photoluminescence (PL) spectroscopy and thermogravimetric analysis (TGA). The results show that the Eu(III) complexes exhibit a high thermal stability,and wide and strong excitation bands when monitored at 613 nm. Excited by ∼395 nm near UV light, the complexes emitted strong and characteristic red light due to f–f transitions of the central Eu³⁺ ion, and no emission from the ligands was found. The photoluminescence mechanism of the europium(III) complexes was investigated and proposed as a ligand-sensitized luminescence process. Among the three europium(III) complexes, Eu(AFTFBD)₃phen exhibits the highest thermal stability and the most excellent photoluminescence properties. A bright red light-emitting diode was fabricated by coating the Eu(AFTFBD)₃phen complex onto an ∼395 nm-emitting InGaN chip, and the LED showed appropriate CIE chromaticity coordinates (x=0.66, y=0.33). A white LED with CIE chromaticity coordinates (x=0.32, y=0.32) was prepared with Eu(AFTFBD)₃phen as red phosphor, indicating that Eu(AFTFBD)₃phen can be applied as a red component for fabrication of near ultraviolet-based white light-emitting diodes.     

Electrical conductivity and luminescence of metal-organic nanocomposites

We presented the results of experimental study of electrical and luminescence properties of planar nanocomposites based on gold island films and layers of efficient organic luminophores — aluminum (III) 8-hydroxyquinolinate (Alq₃) and europium β-diketonates [Eu(DBM)₃ bath, Eu(DBM)₃ phen, and Eu(DBM)₃]. The mechanisms of electroluminescence of such hybrid systems are discussed and the processes of luminescence excitation in the organic component of nanocomposites are considered in detail. It is shown that the spectral characteristics of europium β-diketonates are controlled by the Eu³⁺ ion fluorescence. The proposed mechanisms of nanocomposite electroluminescence are confirmed by the results of measurements of cathodoluminescence spectra of organic luminophores.     

Nile Red Synchronous Scan Fluorescence Spectroscopy to Follow Matrix Modification in Sol–Gel Derived Media and its Effect on the Peroxidase Activity of cytochrome <Emphasis Type="Italic">c</Emphasis>

The highly solvatochromic dye Nile red is used in conjunction with synchronous scan fluorescence spectroscopy to elucidate changes in the internal environment of cytochrome c, upon incorporation into differently modified sol–gel derived media. Nile red was first studied in a variety of solvents in order to quantify changes in polarity. Matrix modifications involved the addition of several silanes, intended to interact with any unreacted hydroxyl entities left from the matrix forming reaction, while polymers were used to help reduce shrinkage and modify the internal pore environment. Slight unfolding of the protein was observed on incorporation into the sol–gel derived media. During the aging process further changes were monitored by using difference synchronous scan fluorescence spectra and complementary measurements of catalytic activity, expressed as the initial velocity. Combining Nile red synchronous scan fluorescence with cytochrome c activity data lead to a method to elucidate effects linked to protein conformation and those related to the sol–gel derived host. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Strong green luminescence of Ni2+-doped ZnS nanocrystals

ZnS nanoparticles doped with Ni²⁺ have been obtained by chemical co-precipitation from homogeneous solutions of zinc and nickel salt compounds, with S^2- as precipitating anion, formed by decomposition of thioacetamide (TAA). The average size of particles doped with different mole ratios, estimated from the Debye–Scherrer formula, is about 2–2.5 nm. The nanoparticles could be doped with nickel during synthesis without altering the X-ray diffraction pattern. A Hitachi M-850 fluorescence spectrophotometer reveals the emission spectra of samples. The absorption spectra show that the excitation spectra of Ni-doped ZnS nanocrystallites are almost the same as those of pure ZnS nanocrystallites (λ_ex=308–310 nm). Because a Ni²⁺ luminescent center is formed in ZnS nanocrystallites, the photoluminescence intensity increases with the amount of ZnS nanoparticles doped with Ni²⁺. Stronger and stable green-light emission (520 nm) (its intensity is about two times that of pure ZnS nanoparticles) has been observed from ZnS nanoparticles doped with Ni²⁺. Received: 18 December 2000 / Accepted: 17 March 2001 / Published online: 20 June 2001     

Energy transfer study of the formation, composition, and size of nanostructures of metal ion complexes in aqueous solutions

We studied the luminescence intensity (I _lum) of the ions Eu(III) and Sm(III) in relation to the concentrations of ions Ln(III) and Al(III) in water at pH 7 at an excess of such beta-diketones as p-methoxybenzoyltrifluoroacetone (MBTA), dibenzoylmethane (DBM), and tenoyltrifluoroacetone (TTA) and in the presence of 1,10-phenanthroline (phen) used as a synergistic agent. Both the enhancement of I _lum (Eu(III)) upon addition of Gd(III) (co-luminescence) and the effect of the third ion are found to depend on the order of addition of the ions to the solution and, therefore, on the sequence of formation of nanostructures of complexes of these ions in the solution, in which the transfer of the triplet energy of the organic part of complexes takes place, leading to an enhancement in I _lum (Eu(III)). The intensity I _lum (Eu(III)) is shown to increase equally rapidly upon addition of either Gd(III) or Al(III) to solutions with DBM + phen. In solutions of all the three beta-diketones studied, the Eu(III) ions incorporate better into nanostructures of triply charged ions whose radius is similar to or smaller than the radius of the Eu(III) ions. Our study of the effect that the replacement of H₂O with D₂O exerts of I _lum of 5 × 10^?8 M Eu(III) at different concentrations of ligands shows that, at [Ln(III)] < [OH^?] and at a concentration of beta-diketones smaller than 3 × 10^?5 M, the deuteration affects I _lum(Eu(III)) and, therefore, the first coordination sphere of Eu(III) contains OH groups. It is shown that, in aqueous solutions with 3 × 10^?5 M TTA + 10^?5 M phen, the increase in I _lum(Eu(III)) caused by the introduction of Gd(III) ions results from two processes occurring in the nanostructures of these complexes: the energy transfer from Gd(III) complexes to Eu(III) complexes and the increase of I _lum of Eu(III) itself under the conditions in the solution where the total concentration [Ln] ? [OH^?] and both the photochemical deactivation of Eu(III) and the exchange of its excitation energy for vibrations of the OH groups are suppressed. The reliability of the size estimation of nanostructures of metal complexes is discussed in terms of the effect of these nanostructures on I _lum of chelates of Eu(III).     

Donor-Acceptor Compound Based on Rhodanineacetic Acid-Pyrene Derivative: Red-Light Emitting Fluorescent Organic Nanoparticles

A donor-acceptor compound based on Rhodanineacetic acid-pyrene derivative (RAAP), which emits weak yellow-green fluorescence in the methanol solution, was investigated. RAAP nanoparticles with a mean diameter of 50–60 nm were prepared by a simple reprecipitation method without surfactants. The observation of RAAP nanoparticles were undertaken through SEM and TEM method. The emission spectra of RAAP nanoparticles are red-shifted (Δ λ_em = 86 nm) to red region and the intensity is 40-fold higher than that in the methanol solution. Both the J-aggregation and aggregation-induced intramolecular planarization are considered to be the probable mechanism of strong emission for RAAP nanoparticles. The excellent sensibility toward organic vapor which profits from its fluorescence switching behavior is well demonstrated by vapor experiment.     

Fluorescence enhancement of samarium complex co-doped with terbium complex in a poly(methyl methacrylate) matrix

The fluorescence property of Sm(DBM)₃phen- (DBM—dibenzoylmethide, phen—1,10-phenanthroline) and Tb(DBM)₃phen-co-doped poly(methyl methacrylate) (PMMA) was investigated. The excitation, emission spectra and fluorescence lifetime of the co-doped samples were examined. In the co-doped samples, the luminescence intensities of Sm³⁺ enhance with an increase of the Tb(DBM)₃phen content and with a decrease of the Sm(DBM)₃phen content. The reason for the fluorescence enhancement effect in the co-doped polymer is the intermolecular energy transfer. To give a vivid picture for this co-doped system, a model for the fluorescence enhancement of Sm(DBM)₃phen- and Tb(DBM)₃phen-co-doped PMMA is presented.     

Enhancement of the fluorescence of triphenylmethane dyes caused by their interaction with nanoparticles from β-diketonate complexes

We have studied the absorption and fluorescence spectra of Malachite Green and Crystal Violet in aqueous and alcoholic-aqueous solutions in which nanoparticles from Ln(III) and Sc(III) diketonates are formed at concentrations of complexes in a solution of 5–30 μM. We have shown that, if the concentrations of the dyes in the solution are lower than 0.5 μM, dye molecules are incorporated completely into nanoparticles or are precipitated onto their surface. The fluorescence intensity of these incorporated and adsorbed Malachite Green and Crystal Violet molecules increases by several orders of magnitude compared to the solution, which takes place because of a sharp increase in the fluorescence quantum yields of these dyes and at the expense of the sensitization of their fluorescence upon energy transfer from β-diketonate complexes entering into the composition of nanoparticles. We have shown that, if there is no concentration quenching, the values of the fluorescence quantum yield of the Crystal Violet dye incorporated into nanoparticles and adsorbed on their surface vary from 0.06 to 0.13, i.e., are close to the fluorescence quantum yield of this dye in solid solutions of sucrose acetate at room temperature. The independence of the fluorescence quantum yield of Crystal Violet on the morphology of nanoparticles testifies to a high binding constant of complexes and the dye. The considerable fluorescence quantum yields of triphenylmethane dyes in nanoparticles and sensitization of their fluorescence by nanoparticle-forming complexes make it possible to determine the concentration of these dyes in aqueous solutions by the luminescent method in the range of up to 1 nM.     

Enhanced activity of chaperonin GroEL in the presence of platinum nanoparticles

The chaperonin protein GroEL was mixed with varying concentrations of K₂PtCl₄ followed by a 20-fold concentration of sodium borohydride to afford GroEL–platinum nanoparticle complexes in a ratio of between 1:25 and 1:2,000. Typical colour change, from colourless or pale yellow to brown, occurred that was dependent on the amount of platinum present. These complexes were characterised by UV/Vis, inductively coupled plasma optical emission spectroscopy, Fourier transform infra red, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy. TEM analysis revealed that the size of nanoparticles increased as the molar ratio of platinum to GroEL increased with an average size diameter of 1.72–3.5 nm generated with GroEL–platinum molar ratios of 1:125–1:2,000. Fourier-transform infrared spectroscopy (FTIR) spectra showed no distinct changes in the structure of GroEL but confirmed that the nanoparticles were attached to the protein. The effect of platinum nanoparticles on the ATPase activity of GroEL showed an activity of 5.60 μmol min⁻¹ ml⁻¹ (87 % increase over a control) at the molar ratio of GroEL–platinum nanoparticles of 1:25.     

Energy migration toward a dye in nanoparticles from complexes with short fluorescent state lifetimes

We have studied regular features of the fluorescence sensitization (cofluorescence) of coumarin 30 and rhodamine 6G introduced into nanoparticles from complexes Ln(PhBTA)₃phen, where PhBTA is p-phenylbenzoyltrifluoroacetone and Ln is a triply charged Pr, Nd, Sm, Eu, Er, or Yb ion, which absorbs in the fluorescence range of ligands of complexes and dyes. We show that both the cofluorescence intensities (I _cofl) of rhodamine 6G in nanoparticles from Sm and Eu complexes and the behavior of intensity I _cofl on the content of rhodamine 6G coincide with the corresponding data obtained for nanoparticles from La and Lu complexes doped with rhodamine 6G molecules. A considerable decrease in I _cofl of rhodamine 6G is observed only in nanoparticles from complexes Nd(PhBTA)₃phen. In nanoparticles from Pr, Nd, Sm, Eu, Er, and Yb complexes doped with coumarin 30, it has been observed that, depending on the choice of the central ion, I _cofl of coumarin 30 is 2 to 80 times lower compared to I _cofl of the dye in nanoparticles from La and Lu complexes. A separate analysis of the influence of these ions on the energy transfer from complexes to coumarin 30 and on the fluorescence intensity of coumarin 30 incorporated into nanoparticles from these ions showed that a decrease in I _cofl of coumarin 30 by a factor of 2?C20 occurs due to the reduction of ??_fl of ligands of complexes under the influence of the interaction with Pr, Nd, Sm, Eu, Er, and Yb ions. Since ??_fl of complexes La(PhBTA)3phen is ??2 ps, while that of complexes Gd(PhBTA)3phen is ??1 ps, then, in nanoparticles with a maximal decrease in I _cofl of coumarin 30, ??_fl of complexes is reduced to ??0.1 ps. It has been found that, in nanoparticles from complexes with this ??_fl, energy migration over complexes takes place. However, as distinct from nanoparticles from La, Lu, and Y complexes, the free path length of singlet excitons in nanoparticles from complexes of absorbing ions is smaller than the nanoparticle size.     

Nucleobase-Specific Enhancement of Cy3 Fluorescence

We report on the role of dye–nucleobase interactions on the photophysical properties of the indocarbocyanine Cy3. The fluorescence efficiency and lifetime of Cy3 increase in the presence of all four nucleoside monophosphates. This behavior correlates with an increase in the activation energy for photoisomerization and a ∼4 nm red shift in the fluorescence spectrum. Changes are more dramatic for the purines (dAMP, dGMP) than the pyrimidines (dCMP, dTMP), and for the nonsulfonated cyanine (DiIC₂(3)) than the sulfonated dye (Cy3–SE). These results are consistent with a model in which Cy3–nucleoside π–π interactions decrease the efficiency of photoisomerization, increasing the efficiency of fluorescence. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effect of co-dopant on the formation and properties of anatase-type titania solid solutions doped with niobium

The effect of co-dopant M (M=gallium (Ga), aluminum (Al), and scandium (Sc)) on the formation, crystallite growth, optical band gap, photocatalytic activity, and phase stability of anatase-type titanium dioxide solid solutions (Ti_1−2XNb_XM_XO₂) containing the same amount of dopant niobium (Nb) that were directly formed as nanoparticles under mild hydrothermal conditions at 180 °C for 5 h was investigated. The composition range X of the anatase-type solid solutions (Ti_1−2XNb_XM_XO₂) depended on the co-dopant M, i.e., X=0.15-0.20 for M=Ga and Al, and X=0.33 for M=Sc. A remarkable increase in the lattice parameter c₀ was detected in the solid solutions co-doped with M=Sc. The increase in the amount of co-dopant M=Ga and Al enhanced the crystallite growth of the anatase-type solid solutions under the hydrothermal conditions. The photocatalytic activity of the solid solutions (Ti_0.80Nb_0.10M_0.10O₂) co-doped with M=Sc, Ga, and Al increased in that order. The co-dopant M=Ga promoted the anatase-to-rutile phase transformation of the solid solutions at lower temperature.     

发红色荧光铽配合物的合成及荧光性能的研究

以二苯甲酰甲烷(HDBM)为第一配体,邻菲罗啉(phen)和二吡啶并[3,2-a:2',3'-c]哇喔啉(dpq)为第二配体合成两种三元铽配合物,并进行元素分析、稀土络合滴定、摩尔电导率、红外光谱、紫外光谱、荧光激发和发射光谱的测定,推测化合物的组成分别为:Tb(DBM)3phen,Tb(DBM)3dpq.DBM通过氧...