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1.
Mingming Zou Ying Li Jun Wang Qi Wang Yumei Kong Jingqun Gao Ping Fan 《Journal of solution chemistry》2013,42(4):849-865
The interaction between bovine serum albumin (BSA) and FeIII complexes with three binary organic acid (biorga) ligands, [FeIII(oxa)(H2O)4]+ (oxa = oxalic acid), [FeIII(pra)(H2O)4]+ (pra = propanedioic acid) and [FeIII(sua)(H2O)4]+ (sua = succinic acid), as well as the sonocatalytic damage of BSA in the presence of these three FeIII–biorga complexes under ultrasonic irradiation, were studied by UV–vis and fluorescence spectra. The experimental results show that the fluorescence quenching process of BSA caused by three FeIII–biorga complexes are all static quenching and the corresponding quenching rate constants (K q), equilibrium constants (K A) and the binding site numbers (n) were calculated. The results reveal that, under ultrasonic irradiation, the BSA molecules were obviously damaged by these FeIII–biorga complexes. In addition, the effects of several factors on the damage of BSA molecules were examined. The experimental results demonstrate that the damage degree of BSA increased with an increase of ultrasonic irradiation time, FeIII–biorga complex concentration, and ionic strength. In comparison, [FeIII(pra)(H2O)4]+ exhibited higher sonocatalytic activity than [FeIII(oxa)(H2O)4]+ and [FeIII(sua)(H2O)4]+. Finally, the extent of generation of $ \cdot {\text{O}}_{2}^{ - } $ · O 2 ? and ·OH during sonocatalytic processes was estimated. Perhaps, the results will be significant for promoting sonodynamic treatment (SDT) of tumors at the molecular level. 相似文献
2.
Zhi Qiu Wang Ying Li Jun Wang Jing Qun Gao Ming Ming Zou Yu Mei Kong Guang Xi Han Ping Fan 《Journal of solution chemistry》2012,41(11):2058-2073
The interaction of bovine serum albumin (BSA) with Fe(III)?Ccitrate complexes ([FeIII(cit)(H2O)3]? and [FeIII(cit)2]5?) and the sonocatalytic damage of BSA under ultrasonic irradiation were studied. Additionally, the various factors influencing the sonocatalytic damage of BSA were also studied by means of UV?CVis and fluorescence spectra. The experimental results indicate that the probable fluorescence quenching mechanisms of BSA by Fe(III)?Ccitrate complexes ([FeIII(cit)(H2O)3]? and [FeIII(cit)2]5?) are both static quenching. Under certain conditions, the degree of damage to BSA is aggravated with increases of ultrasonic irradiation time, Fe(III)?Ccitrate complex concentration, pH value and ionic strength. Moreover, all of the results demonstrate that [FeIII(cit)2]5? displays higher sonocatalytic activity than [FeIII(cit)(H2O)3]? under the same experimental conditions during the damage process of BSA. Finally, the generation of ·O2 ? and ·OH during sonocatalytic processes was estimated using scavengers. Perhaps, the results will be significant for promoting sonodynamic treatment to treat tumors at the molecular level. 相似文献
3.
J. Wang X. D. Zhang Y. Zhang W. G. Jia Zh. R. Liu 《Journal of Structural Chemistry》2004,45(1):114-123
The crystal and molecular structures of the [PrIII(nta)(H2O)2]·H2O (nta = nitrilotriacetic acids), K3[GdIII(nta)2(H2O)]·6H2O, and K3[YbIII(nta)2]·5H2O complexes have been determined by single-crystal X-ray structure analyses. In [PrIII(nta)(H2O)2]·H2O, the PrIIINO8 part forms a nine-coordinate pseudo-monocapped square antiprismatic structure in which one N and three O atoms are from one nta ligand in the same molecule, three O atoms from another nta ligand in the neighboring molecule and two O atoms from two coordinate water molecules. In K3[GdIII(nta)2(H2O)]·6H2O, the [GdIII(nta)2(H2O)3- complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which each nta acts as a tetradentate ligand with one N atom of the amino group and three O atoms of the carboxylic groups. In K3[YbIII(nta)2]·5H2O, each nta also acts as a tetradentate ligand with one N atom of amino group and three O atoms of the carboxylic groups, but the [YbIII(nta)2
3- complex anion has an eight-coordinate structure with a distorted square antiprismatic prism. All the results including those for [TmIII(nta)(H2O)2]·2H2O confirm the inferences on the coordinate structures and coordination numbers of rare earth metal complexes with the nta ligand. 相似文献
4.
Hassan A. Ewais 《Transition Metal Chemistry》2009,34(5):539-547
The oxidation of [CoII(nta)(ox)(H2O)2]3− and [CoII(nta)(ph)(H2O)2]3− (nta = nitrilotriacetate, ox = oxalic acid and ph = phthalic acid) by periodate have been studied kinetically in aqueous
solution over 20–40 °C and a variety of pH ranges. The rate of oxidation of [CoII(nta)(ox)(H2O)2]3− by periodate, obeys the following equation: d[CoIII]/dt = [CoII(nta)(ox)(H2O)23−][H5IO6] {k
4
K
5 + (k
5
K
6
K
2/[H+]} while the reaction of [CoII(nta)(ph)(H2O)2]3− with periodate in aqueous acidic medium obeys the following rate law: d[CoIII]/dt = k
6
K
8[CoII]T [IVII]T/{1 + [H+]/K
7 + K
8[IVII]
T
}. Initial cobalt(III) products were formed and slowly converted to final products, fitting an inner-sphere mechanism. Thermodynamic
activation parameters have been calculated. A common mechanism for the oxidation of ternary nitrilotriacetatocobalt(II) complexes
by periodate is proposed and supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions. 相似文献
5.
M. A. Kiskin A. A. Sidorov G. G. Aleksandrov Yu. G. Shvedenkov V. N. Ikorskii V. M. Novotortsev I. L. Eremenko I. I. Moiseev 《Russian Chemical Bulletin》2005,54(9):2211-2214
The interaction of [K2FeIII
4(O)2(OOCCMe3)10(HOOCCMe3)2(H2O)2]n with 2-pyridinecarboxaldehyde results in a mixed-valence complex FeIIFeIII
3(μ3-O)2(μ2-OOCCMe3)7L2··2.5MeCN·3H2O (L = 2-NC5H4COOH0.75K0.25). The structure of the complex was established by X-ray analysis. The magnetic properties of the complex were studied.
Dedicated to Academician A. L. Buchachenko on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2145–2148, September, 2005. 相似文献
6.
The kinetics of oxidation of [CrIII(Dpc)(Asp)(H2O)2] (Dpc = dipicolinic acid and Asp = DL ‐aspartic acid) by N‐bromosuccinimide (NBS) in aqueous solution have been found to obey the equation: where k2 is the rate constant for the electron transfer process, K1 is the equilibrium constant for deprotonation of [CrIII(Dpc)(Asp)(H2O)2], K2 and K3 are the pre‐equilibrium formation constants of precursor complexes [CrIII(Dpc)(Asp)(H2O)(NBS)] and [CrIII(Dpc)(Asp)(H2O)(OH)(NBS)]?. Values of k2 = 4.85 × 10?2 s?1, K1 = 1.85 × 10?7 mol dm?3, and K2 = 78.2 mol?1 dm3 have been obtained at 30°C and I = 0.1 mol dm?3. The experimental rate law is consistent with a mechanism in which the deprotonated [CrIII(Dpc)(Asp)(H2O)(OH)]? is considered to be the most reactive species compared to its conjugate acid. It is assumed that electron transfer takes place via an inner‐sphere mechanism. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 394–400, 2004 相似文献
7.
The complex ion [FeIII2(μ‐O)(phen)4(H2O)2]4+ ( 1 ) (phen = 1,10‐phenanthroline) and its hydrolytic derivatives [FeIII2(μ‐O)(phen)4(H2O)(OH)]3+ ( 1a ) and [FeIII2(μ‐O)(phen)4‐ (OH)2]2+ ( 2a ) coexist in rapid equilibria in the range pH 4.23–5.35 in the presence of excess phenanthroline (pKa1 = 3.71±0.03, pKa2 = 5.28± 0.07). The solution reacts quantitatively with I− to produce [Fe(phen)3]2+ and I2. Only 1 but none of its hydrolytic derivatives is kinetically active. Both inner and outer sphere pathways operate. The observed rate constants show second‐order dependence on the concentration of iodide, while the dependence on [H+] is complex in nature. Added Cl− inhibits the formation of adduct with I− and thus retards the rate of inner sphere path, leading to a rate saturation at high [Cl−], where only the outer sphere mechanism is active. Kinetic data indicate that simultaneous presence of two I− in the vicinity of diiron core is necessary for the reduction of 1 . © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 737–743, 2005 相似文献
8.
The Building Block [FeIII(pzphen)(CN)4]– and its Lanthanide Complexes: Synthesis,Crystal Structure,and Magnetic Properties 下载免费PDF全文
Jian‐Qing Tao Wen‐Wen Ju Zhou Zhou Li‐Yong Jia Ning‐Ning Chen Yun‐Shan Xue Jun Wang Xing‐Cai Huang 《无机化学与普通化学杂志》2016,642(24):1466-1471
The cyanide building block [FeIII(pzphen)(CN)4]– and its four lanthanide complexes [{FeIII(pzphen)(CN)4}2LnIII(H2O)5(DMF)3] · (NO3) · 2(H2O) · (CH3CN) [Ln = Nd ( 1 ), Sm ( 2 ), DMF = dimethyl formamide] and [{FeIII(pzphen)(CN)4}2LnIII(NO3)(H2O)2(DMF)2](CH3CN) [Ln = Gd ( 3 ), Dy ( 4 )] were synthesized and structurally characterized by single‐crystal X‐ray diffraction. Compounds 1 and 2 are ionic salts with two [FeIII(pzphen)(CN)4]– cations and one LnIII ion, but compounds 3 and 4 are cyano‐bridged FeIII‐LnIII heterometallic 3d‐4f complexes exhibiting a trinuclear structure in the same conditions. Magnetic studies show that compound 3 is antiferromagnetic between the central FeIII and GdIII atoms. Furthermore, the trinuclear cyano‐bridged FeIII2DyIII compound 4 displays no single‐molecular magnets (SMMs) behavior by the alternating current magnetic susceptibility measurements. 相似文献
9.
The behaviour of the Cobalt(III)–nta (nta = nitrilotriacetate) system in an acidic medium was investigated. The acid dissociation constant, pK
a1, of [(nta)(H2O)Co(-OH)Co(H2O)(nta)]– was determined as 3.09(3) and the pK
a of the cis-[Co(nta)(H2O)2]/[Co(nta)(H2O)(OH)]– equilibrium was determined as 6.71(1). cis-[Co(nta)(H2O)2] undergoes ring-opening upon acidification below pH = 2.0. The formation of [Co(
3-nta)(H2O)3]+ was also studied. The substitutions between cis-[Co(nta)(H2O)2] and NCS– ions were investigated in the pH = 2–7 ranges. [Co(nta) (H2O)(OH)]– reacts ca. 70 times faster at 24.7 °C with NCS– ions than cis-[Co(nta)(H2O)2], indicating a cis-labilising effect of the OH– ligand. 相似文献
10.
Two solid complexes, fac–[Cr(gly)3] and [Cr(gly)2(OH)]2, (where gly is glycinato ligand) were prepared and their acid-catalysed aquation products were identified. The structure
of [Cr(gly)3] was solved by X-ray diffraction, revealing a cationic 3D sublattice with perchlorate anions inside its cavities. Acid-catalysed
aquation of [Cr(gly)3] and [Cr(gly)2(OH)]2 leads to the same inert product, [Cr(gly)2(H2O)2]+, in a two-stages process. At the first stage, intermediate complexes, [Cr(gly)2(O–glyH)(H2O)]+ and [Cr(gly)2(H2O)–OH–Cr(gly)2(H2O)]+, are formed respectively. Kinetics of the first aquation stage of [Cr(gly)3] were studied in HClO4 solutions. The dependencies of the pseudo first-order rate constants on [H+] are as follows: k
obs1H = k
0 + k
1
K
p1[H+], where k
0 and k
1 are rate constants for the chelate-ring opening via spontaneous and acid-catalysed reaction paths, respectively, and K
p1 is the protonation constant. The proposed mechanism assumes formation of the reactive intermediate as a result of proton
addition to the coordinated carboxylate group of the didentate ligand. Some kinetic studies on the second reaction stage,
the one-end bonded glycine liberation, were also done. The obtained results were analogous to those for stage I. In this case,
the proposed reactive species are intermediates, protonated at the carboxylate group of the monodentate glycine. Base hydrolysis
of two complexes, [Cr(gly)2(O–gly)(OH)]− and [Cr(gly)2(OH)2]−, was studied in 0.2–1.0 M NaOH. The pseudo first-order rate constants, k
obsOH, were [OH−] independent in the case of [Cr(gly)2(O–gly)(OH)]−, whereas those for [Cr(gly)2(OH)2]− linearly depended on [OH−]. The reaction mechanisms were proposed, where the OH− -catalysed reaction path was rationalized in terms of formation of the reactive conjugate base, [Cr(gly)2(OH)(O)]2−, as a result of OH− ligand deprotonation. Activation parameters were determined and discussed. 相似文献
11.
Heterotrimetallic Coordination Polymers: {CuIILnIIIFeIII} Chains and {NiIILnIIIFeIII} Layers: Synthesis,Crystal Structures,and Magnetic Properties 下载免费PDF全文
Dr. Maria‐Gabriela Alexandru Dr. Diana Visinescu Prof. Marius Andruh Dr. Nadia Marino Dr. Donatella Armentano Dr. Joan Cano Prof. Francesc Lloret Prof. Miguel Julve 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5429-5446
The use of the [FeIII(AA)(CN)4]? complex anion as metalloligand towards the preformed [CuII(valpn)LnIII]3+ or [NiII(valpn)LnIII]3+ heterometallic complex cations (AA=2,2′‐bipyridine (bipy) and 1,10‐phenathroline (phen); H2valpn=1,3‐propanediyl‐bis(2‐iminomethylene‐6‐methoxyphenol)) allowed the preparation of two families of heterotrimetallic complexes: three isostructural 1D coordination polymers of general formula {[CuII(valpn)LnIII(H2O)3(μ‐NC)2FeIII(phen)(CN)2 {(μ‐NC)FeIII(phen)(CN)3}]NO3 ? 7 H2O}n (Ln=Gd ( 1 ), Tb ( 2 ), and Dy ( 3 )) and the trinuclear complex [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3] ? NO3 ? H2O ? CH3CN ( 4 ) were obtained with the [CuII(valpn)LnIII]3+ assembling unit, whereas three isostructural heterotrimetallic 2D networks, {[NiII(valpn)LnIII(ONO2)2(H2O)(μ‐NC)3FeIII(bipy)(CN)] ? 2 H2O ? 2 CH3CN}n (Ln=Gd ( 5 ), Tb ( 6 ), and Dy ( 7 )) resulted with the related [NiII(valpn)LnIII]3+ precursor. The crystal structure of compound 4 consists of discrete heterotrimetallic complex cations, [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3]+, nitrate counterions, and non‐coordinate water and acetonitrile molecules. The heteroleptic {FeIII(bipy)(CN)4} moiety in 5 – 7 acts as a tris‐monodentate ligand towards three {NiII(valpn)LnIII} binuclear nodes leading to heterotrimetallic 2D networks. The ferromagnetic interaction through the diphenoxo bridge in the CuII?LnIII ( 1 – 3 ) and NiII?LnIII ( 5 – 7 ) units, as well as through the single cyanide bridge between the FeIII and either NiII ( 5 – 7 ) or CuII ( 4 ) account for the overall ferromagnetic behavior observed in 1 – 7 . DFT‐type calculations were performed to substantiate the magnetic interactions in 1 , 4 , and 5 . Interestingly, compound 6 exhibits slow relaxation of the magnetization with maxima of the out‐of‐phase ac signals below 4.0 K in the lack of a dc field, the values of the pre‐exponential factor (τo) and energy barrier (Ea) through the Arrhenius equation being 2.0×10?12 s and 29.1 cm?1, respectively. In the case of 7 , the ferromagnetic interactions through the double phenoxo (NiII–DyIII) and single cyanide (FeIII–NiII) pathways are masked by the depopulation of the Stark levels of the DyIII ion, this feature most likely accounting for the continuous decrease of χM T upon cooling observed for this last compound. 相似文献
12.
Kou Hui-Zhong Gao Dong-Zhao Bu Wie-Ming Fan Yu-Guo Liao Dai-Zheng Cheng Peng Jiang Zong-Hui Yan Shi-Ping Wang Geng-Lin Li Tian-Jian Tang Jin-Kui 《Transition Metal Chemistry》2001,26(4-5):457-460
Two CrIII–FeIII complexes, K2[Cr(salen)(H2O)][Fe(CN)6]·H2O (1) and [trans-Cr(tn)2Cl2]3[Fe(CN)6]·6H2O (2), have been prepared. Crystal structure determination shows that complex (2) possesses an ionic salt structure. General physical measurements and magnetic studies indicate that (1) assumes a cyanide-bridged dinuclear structure, and that the CrIII–FeIII magnetic coupling through the cyanide bridge is antiferromagnetic, which can be rationalized by the overlap of magnetic orbitals of the same symmetry. 相似文献
13.
Two cobalt coordination polymers [CoII2(ida)2(H2O)2]n ( 1 ) and [Na2CoIII2(ida)4(H2O)4]n·2nH2O ( 2 ) (H2ida = iminodiacetic acid) have been synthesized and characterized by single‐crystal X‐ray diffraction analysis. Compound 1 exhibits a two‐dimensional framework, in which two cobalt atoms exhibit different coordination environments: one is equatorially coordinated by two ida ligands, while another is coordinated by two water molecules and four ida ligands. It is most interesting that, in compound 2 , the ida ligands exhibit different coordination modes. The organic coordination anions [CoIII(ida)2]— are linked up by sodium ions to form a two‐dimensional layer. 相似文献
14.
Hassan A. Ewais 《国际化学动力学杂志》2008,40(3):103-113
The mechanism of oxidation of ternary complexes, [CoII(nta)(S)(H2O)2]3? and [CoII(nta)(M)(H2O)]3? (nta = nitrilotriacetate acid, S = succinate dianion, and M = malonate dianion), by periodate in aqueous medium has been studied spectrophotometrically over the (20.0–40.0) ± 0.1°C range. The reaction is first order with respect to both [IO4?] and the complex, and the rate decreases over the [H+] range (2.69–56.20) × 10?6 mol dm?3 in both cases. The experimental rate law is consistent with a mechanism in which both the hydroxy complexes [CoII(nta)(S)(H2O)(OH)]4? and [CoII(nta)(M)(OH)]4? are significantly more reactive than their conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of the [CoII(nta)(S)(H2O)2]3?, k1 (3.60 × 10?3 s?1), is greater than the value of k6 (1.54 × 10?3 s?1) for the oxidation of [CoII(nta)(M)(H2O)]3? at 30.0 ± 0.1°C and I = 0.20 mol dm?3. The thermodynamic activation parameters have been calculated. It is assumed that electron transfer takes place via an inner‐sphere mechanism. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 103–113, 2008 相似文献
15.
Summary The kinetics of oxidation of [CrIII(nta)(H2O)2] (nta is nitrilotriacetate) by periodate obey the rate law d[CrVI]/dt=(k2[IO
4
–
]+k3[IO
4
–
]2)[CrIII(nta)(H2O)2] under fixed conditions. The activation parameters are reported and we propose that electron-transfer proceeds via an inner-sphere mechanism. 相似文献
16.
Two Heterometallic–Organic Frameworks Composed of Iron(III)‐Salen‐Based Ligands and d10 Metals: Gas Sorption and Visible‐Light Photocatalytic Degradation of 2‐Chlorophenol 下载免费PDF全文
Dr. Jing Li Dr. Jin Yang Dr. Ying‐Ying Liu Prof. Dr. Jian‐Fang Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4413-4421
Two examples of heterometallic–organic frameworks (HMOFs) composed of dicarboxyl‐functionalized FeIII‐salen complexes and d10 metals (Zn, Cd), [Zn2(Fe‐L)2(μ2‐O)(H2O)2] ? 4 DMF ? 4 H2O ( 1 ) and [Cd2(Fe‐L)2(μ2‐O)(H2O)2] ? 2 DMF ? H2O ( 2 ) (H4L=1,2‐cyclohexanediamino‐N,N′‐bis(3‐methyl‐5‐carboxysalicylidene), have been synthesized and structurally characterized. In 1 and 2 , each square‐pyramidal FeIII atom is embedded in the [N2O2] pocket of an L4? anion, and these units are further bridged by a μ2‐O anion to give an (Fe‐L)2(μ2‐O) dimer. The two carboxylate groups of each L4? anion bridge ZnII or CdII atoms to afford a 3D porous HMOF. The gas sorption and magnetic properties of 1 and 2 have been studied. Remarkably, 1 and 2 show activity for the photocatalytic degradation of 2‐chlorophenol (2‐CP) under visible‐light irradiation, which, to the best of our knowledge, is the first time that this has been observed for FeIII‐salen‐based HMOFs. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(20):2221-2241
Three complexes, Na4[DyIII(dtpa)(H2O)]2?·?16H2O, Na[DyIII(edta)(H2O)3]?·?3.25H2O and Na3[DyIII (nta)2(H2O)]?·?5.5H2O, have been synthesized in aqueous solution and characterized by FT–IR, elemental analyses, TG–DTA and single-crystal X-ray diffraction. Na4[DyIII(dtpa)(H2O)]2?·?16H2O crystallizes in the monoclinic system with P21/n space group, a?=?18.158(10)?Å, b?=?14.968(9)?Å, c?=?20.769(12)?Å, β?=?108.552(9)°, V?=?5351(5)?Å3, Z?=?4, M?=?1517.87?g?mol?1, D c?=?1.879?g?cm?3, μ?=?2.914?mm?1, F(000)?=?3032, and its structure is refined to R 1(F)?=?0.0500 for 9384 observed reflections [I?>?2σ(I)]. Na[DyIII(edta)(H2O)3]?·?3.25H2O crystallizes in the orthorhombic system with Fdd2 space group, a?=?19.338(7)?Å, b?=?35.378(13)?Å, c?=?12.137(5)?Å, β?=?90°, V?=?8303(5)?Å3, Z?=?16, M?=?586.31?g?mol?1, D c?=?1.876?g?cm?3, μ?=?3.690?mm?1, F(000)?=?4632, and its structure is refined to R 1(F)?=?0.0307 for 4027 observed reflections [I?>?2σ(I)]. Na3[DyIII(nta)2(H2O)]?·?5.5H2O crystallizes in the orthorhombic system with Pccn space group, a?=?15.964(12)?Å, b?=?19.665(15)?Å, c?=?14.552(11)?Å, β?=?90°, V?=?4568(6)?Å3, Z?=?8, M?=?724.81?g?mol?1, D c?=?2.102?g?cm?3, μ?=?3.422?mm?1, F(000)?=?2848, and its structure is refined to R 1(F)?=?0.0449 for 4033 observed reflections [I?>?2?σ(I)]. The coordination polyhedra are tricapped trigonal prism for Na4[DyIII(dtpa)(H2O)]2?·?16H2O and Na3[DyIII(nta)2(H2O)]?·?5.5H2O, but monocapped square antiprism for Na[DyIII(edta)(H2O)3]?·?3.25H2O. The crystal structures of these three complexes are completely different from one another. The three-dimensional geometries of three polymers are 3-D layer-shaped structure for Na4[DyIII(dtpa)(H2O)]2?·?16H2O, 1-D zigzag type structure for Na[DyIII(edta)(H2O)3]?·?3.25H2O and a 2-D parallelogram for Na3[DyIII(nta)2(H2O)]?·?5.5H2O. According to thermal analyses, the collapsing temperatures are 356°C for Na4[DyIII(dtpa)(H2O)]2?·?16H2O, 371°C for Na[DyIII(edta)(H2O)3]?·?3.25H2O and 387°C for Na3[DyIII(nta)2(H2O)]?·?5.5H2O, which indicates that their crystal structures are very stable. 相似文献
18.
Dr. Alicja Franke Dr. Christoph Fertinger Prof. Dr. Rudi van Eldik 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(22):6935-6949
The present study focuses on the formation and reactivity of hydroperoxo–iron(III) porphyrin complexes formed in the [FeIII(tpfpp)X]/H2O2/HOO? system (TPFPP=5,10,15,20‐tetrakis(pentafluorophenyl)‐21H,23H‐porphyrin; X=Cl? or CF3SO3?) in acetonitrile under basic conditions at ?15 °C. Depending on the selected reaction conditions and the active form of the catalyst, the formation of high‐spin [FeIII(tpfpp)(OOH)] and low‐spin [FeIII(tpfpp)(OH)(OOH)] could be observed with the application of a low‐temperature rapid‐scan UV/Vis spectroscopic technique. Axial ligation and the spin state of the iron(III) center control the mode of O? O bond cleavage in the corresponding hydroperoxo porphyrin species. A mechanistic changeover from homo‐ to heterolytic O? O bond cleavage is observed for high‐ [FeIII(tpfpp)(OOH)] and low‐spin [FeIII(tpfpp)(OH)(OOH)] complexes, respectively. In contrast to other iron(III) hydroperoxo complexes with electron‐rich porphyrin ligands, electron‐deficient [FeIII(tpfpp)(OH)(OOH)] was stable under relatively mild conditions and could therefore be investigated directly in the oxygenation reactions of selected organic substrates. The very low reactivity of [FeIII(tpfpp)(OH)(OOH)] towards organic substrates implied that the ferric hydroperoxo intermediate must be a very sluggish oxidant compared with the iron(IV)–oxo porphyrin π‐cation radical intermediate in the catalytic oxygenation reactions of cytochrome P450. 相似文献
19.
Two novel cyano-bridged lanthanide-transition-metal complexes, K[Fe(bipy)(CN)4
2Tb(H2O)4]·3H2O (1) and [Fe(bipy)(CN)4Sm(phen)(NO2)(H2O)2]·H2O (2) (bipy = 2.2-bipyridine; phen = 1, 10-phenanthroline), have been prepared and structurally characterized. Complex (1) possesses a cyano-bridged two-dimensional (2D) honeycomb-like structure with centrosymmetric [FeII(bipy)(CN)4
2TbIII(H2O)4]– anions, potassium cations, and water of crystallization molecules. Complex (2) consists of a cyano-bridged one-dimensional (1D) ladder structure with neutral [FeII(bipy)(CN)4SmIII(phen)(NO2)(H2O)2] and water of crystallization molecules. The magnetic properties of (1) have been investigated in the 2.0–300 K range. The data for (1) reveal that magnetic interactions between Tb3+ ions through the low-spin Fe2+ ions are negligible. 相似文献
20.
Bipyrimidines have been chosen as (N∧N)(N∧N) bridging ligands for connecting metal centers. IrIII-LnIII (Ln = Nd, Yb, Er) bimetallic complexes [Ir(dfppy)2(μ-bpm)Ln(TTA)3]Cl were synthesized by using Ir(dfppy)2(bpm)Cl as the ligand coordinating to lanthanide complexes Ln(TTA)3·2H2O. The stability constants between Ir(dfppy)2(bpm)Cl and lanthanide ions were measured by fluorescence titration. The obvious quenching of visible emission from IrIII complex in the IrIII-LnIII (Ln = Nd, Yb, Er) bimetallic complexes indicates that energy transfer occurred from IrIII center to lanthanides. NIR emissions from NdIII, YbIII, and ErIII were obtained under the excitation of visible light by selective excitation of the IrIII-based chromophore. It was proven that Ir(dfppy)2(bpm)Cl as the ligand could effectively sensitize NIR emission from NdIII, YbIII, and ErIII. 相似文献