Direct fluorescence detection of Pb2+ and Cd2+ by high-performance liquid chromatography using 1-(4-aminobenzyl)ethylenediamine-N,N,N',N'-tetraacetate as a pre-column derivatizing agent

A highly sensitive HPLC with direct fluorescent detection (lambda(ex) = 235 nm, lambda(em) = 355 nm) was developed for Pb2+ and Cd2+ complexes with an aromatic polyaminocarboxylate, 1-(4-aminobenzyl)ethylenediamine-N,N,N',N'-tetraacetate as a pre-column derivatizing agent. A reversed phase partition column pretreated by a cationic surfactant was employed. Although this ligand forms thermodynamically stable complexes with various metal ions, only peaks of Pb2+ and Cd2+ were detected with the ligand-centered emission in the HPLC due to the emissive activity and kinetic stability in the dissociation reaction. The detection limits obtained were 1.5x10(-8) and 3.3x10(-9) mol l(-1) for Pb2+ and Cd2+, respectively.     

Porphyrin, phthalocyanine and porphyrazine derivatives with multifluorenyl substituents as efficient deep-red emitters

The synthesis and photophysical properties are described for a series of porphyrin, phthalocyanine and pyrazinoporphyrazine derivatives which bear four or eight peripheral fluorenyl substituents as antennae. Representative examples are 5,10,15,20-tetra(9,9-dihexyl-9H-fluoren-2-yl)porphyrin (2), 5,10,15,20-tetrakis[4-(9,9-dihexyl-9H-fluoren-2-yl)phenyl]porphyrin (3), 2,3,9,10,16,17,23,24-octakis(9,9-dihexyl-9H-fluoren-2-yl)-29H,31H-phthalocyanine (8) and 2,3,9,10,16,17,23,24-octakis[4-(9,9-dihexyl-9H-fluoren-2-yl)phenyl]-29H,31H-tetrapyrazinoporphyrazine (9). Palladium-mediated Suzuki-Miyaura cross-coupling reactions have been key steps for attaching the substituents. The compounds are deep-red emitters: lambda(max)(em)=659 (3), 737 (8) and 684 nm (9). Their absorption and emission spectra, their fluorescence lifetimes and quantum yields are correlated with the structures of the macrocycles and the substituents. The solution fluorescence quantum yields of porphyrin derivatives substituted with fluorene (2-4) and terphenyl substituents (7) (Phi(f)=0.21-0.23) are approximately twice that of tetraphenylporphyrin. For phthalocyanine derivative 8, Phi(f) was very high (0.88). Specific excitation of the fluorene units of 8 produced emission from both of them (lambda(max)=480 nm) and also from the phthalocyanine core (lambda(max)=750 nm), indicating a competitive rate of energy transfer and radiative decay of the fluorenes. Organic light-emitting devices (OLEDs) were made by spin-coating techniques by using a polyspirobifluorene (PSBF) copolymer as the host blended with 3 (5 wt. %) in the configuration ITO/PEDOT:PSS/PSBF copolymer:3/Ca/Al. Deep-red emission (lambda(max)=663 nm; CIE coordinates x=0.70, y=0.27) was observed with an external quantum efficiency of 2.5 % (photons/electron) (at 7.5 mA cm(-2)), a low turn-on voltage and high emission intensity (luminance) of 5500 cd m(-2) (at 250 mA/ m(2)).     

Emission analysis of Sm(3+) and Dy(3+):MgLaLiSi(2)O(7) powder phosphors

This paper reports on the structural and emission properties of newly synthesized Sm(3+) and Dy(3+):MgLaLiSi(2)O(7) powder phosphors based on the measurement of their XRD, SEM, FTIR and photoluminescence spectra. Emission spectra of the Sm(3+):MgLaLiSi(2)O(7) phosphors with lambda(exci)=402 nm ((6)H(5/2)-->(4)F(7/2)) and Dy(3+):MgLaLiSi(2)O(7) phosphors with lambda(exci)=385 nm ((6)H(15/2)-->(4)I(13/2)) have been analyzed. Emission mechanisms of these phosphors have also been explained.     

New in situ cleavage of both S-S and S-C(sp2) bonds and rearrangement reactions toward the construction of copper(I) cluster-based coordination networks

Solvothermal reaction of 4,4'-dithiodipyridine (dtdp) with CuI at 120 or 160 degrees C results in the formation of three new coordination networks formulated with [Cu4I4(tdp)2] (1; tdp = 4,4'-thiodipyridine), [Cu5I5(ptp)2] (2), and [Cu6I6(ptp)2] [3; ptp = 1-(4-pyridyl)-4-thiopyridine]. The starting dtdp reagent was unprecedentedly converted into two tdp and ptp ligands via new in situ cleavage of both S-S and S-C(sp2) bonds and temperature-dependent in situ ligand rearrangement of dtdp. 1 is a two-dimensional (2D) Cu4I4 cubane-like coordination network of 2-fold interpenetration. While in 2, the Cu8I8 and Cu2I2 cluster units are alternately connected by the mu2-sulfur bridges into one-dimensional inorganic chains along the a axis, which are further joined by the ptp spacers into a three-dimensional (3D) coordination network of 2-fold interpenetration. 3 is a 3D non-interpenetrating coordination network constructed with 2D inorganic (Cu2I2)n layers and the ptp spacers. 1 displays an intense orange-red emission light with a maximum at ca. 563 nm. While luminescence quenching occurs in 2 and 3 by electron transfer of a photoelectron to the electronegative acceptor molecule of ptp.     

Phosphole-Fused Dehydropurpurins via Titanium-Mediated [2+2+1] Cyclization Strategy

A [2+2+1] cyclization strategy of bis(alkynyl)porphyrin using low-valent titanium species, generated in situ, afforded phosphole-fused dehydropurpurins for the first time. The systematic investigations on the electronic properties of the dehydropurpurins revealed their unique features owing to the oxidation states of the phosphorus atom on the fused phosphole ring. The phosphole P=O and P=S derivatives were found to possess high electron-accepting character derived from phosphorus(V) centers without the contribution of 24π antiaromatic character, suggesting their potential utility as electron-accepting materials. In contrast, the phosphorus(III) derivatives revealed different optical and electrochemical properties arising from both 18π aromatic and 24π antiaromatic networks including the lone pair of the phosphorus(III) atom. Overall, the oxidation state of the phosphorus atom has a clear impact on the whole electronic properties, demonstrating the advantages of chemical modifications of the phosphorus center for creating an exotic π-system. The application of titanium-mediated [2+2+1] cyclization to porphyrins is highly promising for expanding a world of heterole-fused porphyrinoids.     

芳氧功能化咪唑基五氯化铕[HO-4,6-di-tBu-C6H2-2-CH2{CH（NCHCHNiPr）}]2+[EuCl5（THF）]2-的合成与结构

芳氧功能化咪唑盐L+Cl-(L=HO-4,6-di-tBu-C6H2-2-CH2{CH[iPrNCHCHN]})与无水EuCl3分别按照摩尔比为1∶2和1∶3反应成功合成相同芳氧功能化咪唑基五氯化铕L+2[EuCl5(THF)]2-,产物通过元素分析、IR、X-ray射线衍射表征。晶体结构数据表明此配合物属于单斜晶体,空间群P21/c,晶胞参数a=0.96664(8)nm,b=1.63312(12)nm,c=3.6850(3)nm,β=97.600(2)°,V=5.7662(8)nm3,Mr=1060.30,Z=4,Dc=1.221 Mg/m3,μ(MoKα)=1.36 mm-1,F(000)=2200。目标化合物是由阴离子[EuCl5(THF)]2-和[HO-4,6-di-tBu-C6H2-2-CH2{CH(iPrNCHCHN)}]2+通过氢键作用而形成的空间网状结构的晶体,阴离子中中心金属(Eu)是由五个氯原子以及来自THF的氧原子形成扭曲八面体的构型。     

Photoinitiated catalysis in Nafion membranes containing palladium(II) meso-tetrakis(N-methyl-4-pyridyl)porphyrin and iron(III) meso-tetrakis-(2,6-dichlorophenyl)porphyrin for O2-mediated oxidations of alkenes

Immobilisation of both palladium(II) meso-tetrakis(N-methyl-4-pyridyl)porphyrin (PdTMPyP4+) and iron(III) meso-tetrakis(2,6-dichlorophenyl)porphyrin (FeTDCPP+) in the same membrane of Nafion creates a new composite system, in which the photoexcited palladium complex induces the O2-mediated oxidation of cyclohexene to the corresponding allylic hydroperoxide and the iron porphyrin works as a catalyst for specific oxygenations of cyclohexene and cyclooctene. The role of PdTMPyP4+ is to induce the photoactivation of O2 with visible light (lambda > 500 nm) to generate singlet oxygen (1O2) by means of energy transfer from the excited triplet state. Consequently, the 1O2-mediated oxidation of cyclohexene to cyclohexenyl hydroperoxide can be realised with a selectivity greater than 90%. Spectroscopic and photophysical investigations show that the tetracationic palladium porphyrin is mainly fixed to the external part of the Nafion membrane, it is characterised by a triplet-state lifetime significantly higher than that in the solution phase. The monocationic FeTDCPP+ is able to diffuse into the anionic cavities of Nafion, where it works as a catalyst for O2-mediated autooxidation processes that are initiated by the photogenerated hydroperoxides. These processes continue in the dark for many hours giving cyclohex-2-en-1-ol and trans-cyclohexane-1,2-diol monoethyl ether as main oxidation products. The presence of this ether, indirectly, reveals the formation of cyclohexene epoxide which undergoes a nucleophilic attack by ethanol and epoxide opening because of the strong acidic environment inside Nafion. The good photocatalytic efficiency of the oxidation process is demonstrated by an overall quantum yield of 1.1, as well as by a turnover value of 4.7 x 10(3) with respect to the iron porphyrin. When cyclooctene is present as co-substrate, it also undergoes oxygenation. In contrast to what was observed for cyclohexene, cyclooctene epoxide can be accumulated in a significant amount. As far as the stability of the system is concerned, FeTDCPP+ undergoes about 1% degradation during the process, while the Nafion matrix can be utilised several times without observable modification.     

O-半乳吡喃糖基N,N-二(2-氯乙基)磷酰二胺酯的合成及其晶体结构

为探讨糖基磷酰胺酯类化合物的抗肿瘤活性,用三氯氧磷作磷酰化试剂,合成了标题化合物.通过重结晶,分离出标题化合物的一个纯异构体.经X射线衍射单晶结构分析,该晶体属单斜晶系,空间群P2₁,a=1.3474(5)nm,b=1.0624(4)nm,c=1.6916(5)nm,β=110.55(3)°,z=4,D_x=1.35g/cm³.收集到独立衍射点4379个,其中2159个为可观测点.最终一致性因子R=0.079.结构分析结果表明,反应中形成的手性磷原子为R构型.     

Structure of the Manganese (V) Complex-Mn·3/2(μ-DHBQ)·4H_2O·2Cl

FewcompoundswithMninthe 5oxidationstatewerestructuraIlycharacterizedsofaLC.L.HilIlfirstdeterminedthecrystalstructUreoftheMn(V)complex:NMnTpMPP-Nitriodotrtrakis(p-methoxyphenyl)porphinnato-manganese(V).Thepapers'-'reportedseveralnovelmanganese(V)and(Vl)complexes.RecentpublicationshavebeenestablishedthatthecoordinationcompoundsofhighvaIentmanganesedisplaymanyinterestingfeatures.Theyshowabilitytoundergointramolecularinterligandormetal-ligandelectrontransferreaction,especiallyonthenatUreo…     

镧系四元混配化合物[Ln(BA)2(NO3)(phen)]2的合成、晶体结构和波谱研究

在酸性介质、含水溶剂中合成了四元混配化合物[Ln(BA)₂(NO₃)(phen)]₂(BA=苯甲酸根;Ln=La,Ce,Pr,Nd,Sm,Eu,Dy,Gd,Tb,Er),用元素分析、IR、DTA-TG等方法对配合物进行了表征.研究了配合物的顺磁性能和荧光性能.镨配合物的单晶衍射结果表明,配合物属三斜晶系,双核,Pr³⁺的配位数为9,4个BA呈二种配位方式,丰富了四元配合物的结构表现形式.     

镧系四元混合阴离子配合物［Pr(CH3CH2COO)2(NO3)(phen)2］合成和晶体结构

在含水溶剂、酸性环境中合成了镧系四元混合阴离子配合物［Pr(CH₃CH₂COO)₂(NO₃)(phen)］₂并解析了其晶体结构,三斜,空间群P1,a=0.9650(2) nm, b=1.2949(4) nm,c=0.8994(2)nm, α=95.37(3)°,β=111.05(2)°,γ=102.87(2)°,V=1.0037(5) nm^{3, Dc=1.758 g·cm-3, Z=1, F(000)=528, μ(MoKα)=24.64 cm-1, R=0.024, R_W=0.034。四个丙酸根呈二种配位方式,Pr3+为九配位。}     

meso-四[(4-苯乙烯氨基)苯基]卟啉合成及其波谱特点

以吡咯和对硝基苯甲醛为原料,经过环化、还原和缩合,合成了meso-四[(4-苯乙烯氨基)苯基]卟啉(TBAPP),通过UV-Vis、FT-IR、1H NMR及元素分析等对产物进行了表征,并对其荧光和电子顺磁共振特性进行了研究。 卟啉产物的EPR测定显示出游离基特征,表明卟啉分子的大π共轭结构对周边基团产生的自由基有稳定作用。 取代基对卟啉的紫外 可见吸收、光致发光及电子顺磁共振特性均有影响。 四席夫碱苯基卟啉TBAPP的Q带比前体四氨基卟啉（TAPP）和母体四硝苯基卟啉（TNPP）红移,而Soret谱带变化较小;TBAPP的440 nm光激发的最大荧光峰658 nm分别比TAPP蓝移5 nm和比TNPP红移9 nm;TBAPP的EPR精细结构比TAPP弱,而比TNPP强。     

二高氯酸根.(二亚乙基三胺).咪唑合铜(Ⅱ)的合成与结构

已知多种金属酶和金属蛋白中的金属离子与肽链上的组氨酸残基的咪唑基配位构成其活性中心的重要部分。在Cu、Zn超氧化物歧化酶和细胞色素C氧化酶a_3中、组氨酸的咪唑基成为连接Cu、Zn或Cu、Fe原子的桥基尤为突出。作为超氧化物歧化酶活性中心结构与性能关联研究的一部分,我们首先合成一初级物[Cu(ImH)(dien)(ClO_4)_2并用X光单晶衍射测定了它的结构。按衍射系统消光,晶体属于正交晶系空间群Pna2_1或Pnma。由于分子中重原子的特殊分布和咪唑环的无序取向,按这两个空间群均可得到晶体结构相近的解析结果,从而面临在有心和无心空间群对之间作出选择这一棘手问题。本文主要报导按Pnma求解结构和分子结构的特征。     

3-硝基-1，2，4-三唑-5-酮二甲胺盐（CH3）2NH2^＋C2N4O3H^-的合成、晶体结构和量子化学研究

利用3-硝基-1，2，4-三唑-5-酮(NTO)的乙醇溶液与二甲胺的水溶液合成了 NTO的二甲胺盐(CH_3)_2NH_2~+C_2N_4O_3H~-，在二甲基甲酰胺(DMF)和甲醇的混合 溶剂（体积比为1:5）中培养出单晶。通过X射线单晶结构分析法测定分子结构和晶 体结构，晶体属单斜晶系，空间群为P2(1)/c，晶胞参数为：a=0.7116(1)nm, b=0. 8735(2) nm, c=1.3160(3)nm, β=101.12(2) °,V=0.8026(3)nm~3, D_c=1.450 g/cm~3, Z=4, F(000)=368。采取HF/6-31+G(d)和MP2/6-31+G(d)以及B3LYP/6- 31+G(d)方法对标题化合物进行了几何全优化，并对其成键情况、原子净电荷分布 及化合物的稳定性进行了分析。     

Synthesis and Crystal Structure of a Cu2+ Supra-molecular Complex [Na2Cu(BTA)2(H2O)8]·H2Owith a Three-dimensional Network Structure

A three-dimensional Cu2+ supramolecular complex [Na2Cu(BTA)2(H2O)8]·H2O 1 (H2BTA = bistetrazolylamine) was synthesized by reacting the aqueous solution of CuSO4·5H2O and H2BTA under stirring. The crystal structure of 1 was determined by single-crystal X-ray diffraction. The result indicates that 1 crystallizes in triclinic,space group P1,with a = 7.0518(2),b = 12.2692(2),c = 13.8583(3) ,α = 115.7260(10),β = 93.2440(10),γ = 98.3610(10)o,Mr = 573.90,V = 1059.01(4) 3,Z = 2,Dc = 1.800 g·cm-3,μ(MoKα) = 1.155 mm-1,F(000) = 586.0,S = 1.074,the final R = 0.0273 and wR = 0.0744 for 4334 observed reflections with Ⅰ > 2σ(Ⅰ). The Cu2+ ion is five-coordinated with a N4O1 donor set with τ = 0.153 according to the method of Addison et al. And the Na+ ions form an infinite main chain through bridging O atoms from coordinated water molecules. In 1,a three-dimensional supramolecular network is formed by O-H···O,O-H···N,N-H···O and N-H···N hydrogen bonds.     

Ultra-trace determination of S-nitrosothiols in blood samples by spectrofluorimetry with 8-(3',4'-diaminophenyl)-difluoroboradiaza-s-indacene

Increasing evidence suggests that S-nitrosothiols (RSNO) may represent naturally occurring nitric oxide (NO) surrogates and function as intermediates in NO metabolism. In this work, a simple, sensitive, and selective micromethod is developed and validated for quantification of RSNO. A fluorescent probe 8-(3',4'-diaminophenyl)-difluoroboradiaza-s-indacence (DABODIPY) is firstly used to label RSNO. The derivatization reaction is performed in aqueous medium at 30 degrees C for 15min in the presence of 6x10(-5)molL(-1)Hg2+ and the derivative is detected by fluorescence at lambda(ex)/lambda(em)=500/510nm. A linear function of concentration in the range of (2.0-600.0)x10(-8)molL(-1) is observed with a correlation coefficient of 0.9992 and detection limit of 1.2x10(-9)molL(-1) (S/N=3). This technique has been successfully applied to quantify RSNO in some human blood samples including healthy persons and patients suffering from cardiovascular diseases.     

A femtosecond study of excitation wavelength dependence of a triblock copolymer-surfactant supramolecular assembly: (PEO)20-(PPO)70-(PEO)20 and CTAC

Solvation dynamics and anisotropy decay of coumarin 480 (C480) in a supramolecular assembly containing a triblock copolymer, PEO20-PPO70-PEO20 (Pluronic P123) and a surfactant, CTAC (cetyl trimethylammonium chloride) are studied by femtosecond up-conversion. In a P123-CTAC complex, C480 displays a significant (22 nm) red edge excitation shift (REES) in the emission maximum as lambda ex increases from 335 to 445 nm. This suggests that the P123-CTAC aggregate is quite heterogeneous. The average rotational relaxation time (tau rot) of C480 in a P123-CTAC complex decreases by a factor of 2 from 2500 ps at lambda ex = 375 nm to 1200 ps at lambda ex = 435 nm. For lambda ex = 375 nm, the probe molecules in the buried core region of P123-CTAC are excited and the solvation dynamics displays three components, 2, 60, and 4000 ps. It is argued that insertion of CTAC in P123 micelle affects the polymer chain dynamics, and this leads to reduction of the 130 ps component of P123 micelle to 60 ps in P123-CTAC. For lambda ex = 435 nm, which selects the peripheral highly polar corona region, solvation dynamics in P123-CTAC and P123 are extremely fast with a major component of <0.3 ps ( approximately 80%) and a 2 ps ( approximately 20%) component.     

Infrared (1.2-1.6 microm) luminescence in Cr4+:Yb3Al5O12 single crystal with 940 nm diode pumping

Infrared (1.2-1.6 microm) luminescence in a ytterbium aluminium garnet (YbAG) crystal, doped with Cr (0.05at.%) ions, was investigated under CW laser diode pumping (lambda=940 nm). The Cr4+ emission band was observed with its peak at 1.34 microm and measured to be about 1.3 times with respect to Yb3+ IR luminescence (lambda=1.03 microm). We demonstrate that for the excitation wavelength of 940 nm Yb3+ ions act as sensitizers of the 3B2(3T2)-3B1(3A2) emission of Cr4+ ions. This crystal is promising as a high-efficient system for tunable laser (1.2-1.6 microm) output.     

Density functional theory study of trans-dioxo complexes of iron, ruthenium, and osmium with saturated amine ligands, trans-[M(O)2(NH3)2(NMeH2)2]2+ (M=Fe, Ru, Os), and detection of [Fe(qpy)(O)2]n+ (n=1, 2) by high-resolution ESI mass spectrometry

Density functional theory (DFT) calculations on trans-dioxo metal complexes containing saturated amine ligands, trans-[M(O)2(NH3)2(NMeH2)2]2+ (M=Fe, Ru, Os), were performed with different types of density functionals (DFs): 1) pure generalized gradient approximations (pure GGAs): PW91, BP86, and OLYP; 2) meta-GGAs: VSXC and HCTH407; and 3) hybrid DFs: B3LYP and PBE1PBE. With pure GGAs and meta-GGAs, a singlet d2 ground state for trans-[Fe(O)2(NH3)2(NMeH2)2]2+ was obtained, but a quintet ground state was predicted by the hybrid DFs B3LYP and PBE1PBE. The lowest transition energies in water were calculated to be at lambda approximately 509 and 515 nm in the respective ground-state geometries from PW91 and B3LYP calculations. The nature of this transition is dependent on the DFs used: a ligand-to-metal charge-transfer (LMCT) transition with PW91, but a pi(Fe-O)-->pi*(Fe-O) transition with B3LYP, in which pi and pi* are the bonding and antibonding combinations between the dpi(Fe) and ppi(O(2-)) orbitals. The FeVI/V reduction potential of trans-[Fe(O)2(NH3)2NMeH2)2]2+ was estimated to be +1.30 V versus NHE based on PW91 results. The [Fe(qpy)(O)2](n+) (qpy=2,2':6',2':6',2':6',2'-quinquepyridine; n=1 and 2) ions, tentatively assigned to dioxo iron(V) and dioxo iron(VI), respectively, were detected in the gas phase by high-resolution ESI-MS spectroscopy.     

Synthesis, characterization, and reactivities of manganese(V)-oxo porphyrin complexes

The reactions of manganese(III) porphyrin complexes with terminal oxidants, such as m-chloroperbenzoic acid, iodosylarenes, and H(2)O(2), produced high-valent manganese(V)-oxo porphyrins in the presence of base in organic solvents at room temperature. The manganese(V)-oxo porphyrins have been characterized with various spectroscopic techniques, including UV-vis, EPR, 1H and 19F NMR, resonance Raman, and X-ray absorption spectroscopy. The combined spectroscopic results indicate that the manganese(V)-oxo porphyrins are diamagnetic low-spin (S = 0) species with a longer, weaker Mn-O bond than in previously reported Mn(V)-oxo complexes of non-porphyrin ligands. This is indicative of double-bond character between the manganese(V) ion and the oxygen atom and may be attributed to the presence of a trans axial ligand. The [(Porp)Mn(V)=O](+) species are stable in the presence of base at room temperature. The stability of the intermediates is dependent on base concentration. In the absence of base, (Porp)Mn(IV)=O is generated instead of the [(Porp)Mn(V)=O](+) species. The stability of the [(Porp)Mn(V)=O](+) species also depends on the electronic nature of the porphyrin ligands: [(Porp)Mn(V)=O](+) complexes bearing electron-deficient porphyrin ligands are more stable than those bearing electron-rich porphyrins. Reactivity studies of manganese(V)-oxo porphyrins revealed that the intermediates are capable of oxygenating PPh(3) and thioanisoles, but not olefins and alkanes at room temperature. These results indicate that the oxidizing power of [(Porp)Mn(V)=O](+) is low in the presence of base. However, when the [(Porp)Mn(V)=O](+) complexes were associated with iodosylbenzene in the presence of olefins and alkanes, high yields of oxygenated products were obtained in the catalytic olefin epoxidation and alkane hydroxylation reactions. Mechanistic aspects, such as oxygen exchange between [(Porp)Mn(V)=16O](+) and H(2)(18)O, are also discussed.