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1.
Two long-chain multidentate ligands: 2,9-di-(n-2′,5′,8′-triazanonyl)-1,10-phenanthroline (L1) and 2,9-di-(n-4′,7′,10′-triazaundecyl)-1,10-phenanthroline (L2) were synthesized. The hydrolytic kinetics of p-nitrophenyl phosphate (NPP) catalyzed by complexes of L1 and L2 with La(III) and Gd(III) have been studied in aqueous solution at 298 K, I = 0.10 mol · dm−3 KNO3 at pH 7.5–9.1, respectively. The study shows that the catalytic effect of GdL1 was the best in the four complexes for hydrolysis
of NPP. Its kLnLH−1, k
LnL and pK
a are 0.0127 mol−1 dm3 s−1, 0.000022 mol−1 dm3 s−1 and 8.90, respectively. This paper expounds the result from the structure of the ligands and the properties of the metal
ions, and deduces the catalysis mechanism. 相似文献
2.
Two multidentate ligands: N,N′-di-(propionic acid-2′-yl-)-2,9-di-aminomethylphenanthroline (L1) and N,N′-di-(3′-methylbutyric acid-2′-yl-)-2,9-di-amino-methylphenanthroline (L2) were synthesized and fully characterized by 1H NMR and elemental analysis. The binding ability of L1 and L2 to metal ions such as M(II) (M = Cu, Zn, Co and Ni) and Ln(III) (Ln = La, Nd, Sm, Eu, and Gd) has been investigated by potentiometric
titration in aqueous solution and 0.1 mol dm−3KNO3 at 25.0 ± °C. In view of the structure of L1 and L2, mononuclear metal complexes can be formed in solution. The stability constants of binary complexes of ligands L1 and L2
with metal ions M(II) and Ln(III) have been determined respectively and further discussed. 相似文献
3.
Two novel multidentate ligands: 2,9-bis-
-1,10-phenanthroline(L1) and 2,9-bis-
-1,10-phenanthroline(L2) were synthesized and characterized by elemental analysis and 1H-n.m.r. spectroscopy. Protonation of the ligands and the stability of complexes of the ligands with rare earth metal ions
were investigated. The mononuclear metal complexes [GdIII and SmIII] of the ligands were studied as catalysts for the transphosphorylation of the RNA-model substrate 2-hydroxypropyl-p-nitrophenylphosphate(HPNP). Kinetic studies show the second-order rate constants of HPNP hydrolysis catalyzed by complexes
LnL and LnLH−1, respectively. We found that both LnL and LnLH−1 have catalytic activity, but GdL1H−1 was the most efficient catalyst of them, which indicated that the structure of the ligands has obviously influence on the
activity of corresponding complexes. A new mechanism was proposed for HPNP hydrolysis reaction catalyzed by LnL and LnLH−1. 相似文献
4.
One multidentate ligand, 1,13-di-(1,10-phenanthroline-2-methylene)-1,4,7,10,13-pentaazatridecane(L), has been synthesized
and characterized. The kinetics of hydrolysis of 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) and p-nitrophenyl phosphate (NPP) catalyzed by complexes of L with Zn2+ have been studied. Both Zn2L and Zn2LH−1 had the ability to catalysis a hydrolysis of HPNP and NPP, and the kinetics of hydrolysis of HPNP and NPP were examined in
aqueous solution at 25.0 ± 0.1 °C, I = 0.1 mol dm−3 KNO3 at the pH range of 7.0–8.5, respectively. Kinetic studies showed that Zn2LH−1 was a more active species than Zn2L in the hydrolysis of HPNP and NPP. A new mechanism was proposed for the hydrolysis of HPNP and NPP catalyzed by Zn2L and Zn2LH−1. 相似文献
5.
Three novel tripodal ligands, N,N′,N′′-tri-(3′-phenylpropionic acid-2′-yl-)-1,3,5-triaminomethylbenzene (Ll), N,N′,N′′-tri-(4′-methylvaleric acid-2′-y1-)-1,3,5-triaminomethylbenzene (L2) and N,N′,N′′-tri-(3′methylvaleric acid-2′-yl-)-1,3,5-triaminomethylbenzene (L3), have been synthesized and fully characterized. The
stabilizing ability of complexes of the three ligands with transition metal ions Cu(II), Ni(II), Zn(II) and Co(II) and rare
earth metal ions La(III), Nd(III), Sm(III), Eu(III) and Gd(III) has been investigated by the pontentiometric method in water
and in aqueous KNO3 (0.1 mol dm−3) at 25.0±0.1 °C, respectively. The results show that there is a great deal of difference between two series of complexes’
stabilities. An explanation of the difference has been given. 相似文献
6.
Five chloroanilato-bridged manganese(II) binuclear complexes, [Mn2(CA)L4](ClO4)2, where L = 4,4′-dimethyl-2,2′-bipyridine (Me2-bpy), 5-methyl-1,10-phenanthroline (Me-phen), 5-chloro-1,10-phenanthroline (Cl-phen), 5-nitro-1,10-phenanthroline (NO2-phen) and 2,9-dimethyl-1,10-phenanthroline (Me2-phen), and CA represents the dianion of chloroanilic acid, have been synthesized and characterized by elemental analyses,
molar conductivity and room temperature magnetic moment measurements, and by spectroscopy. It is proposed that these complexes
have CA-bridged structures and consist of two manganese(II) ions in a distorted-octahedral environment. The complexes [Mn2(CA)(Me2-bpy)4](ClO4)2
(1) and [Mn2(CA)(Me-phen)4](ClO4)2
(2) were characterized by variable temperature magnetic susceptibility measurements (4–300 K) and the observed data were successfully
simulated by an equation based on the spin Hamiltonian operator, Ĥ = −2JŜ
1
Ŝ
2, giving the exchange integral J = −1.98 cm−1 for (1) and J = −2.41 cm−1 for (2). This result indicates that there is a weak antiferromagnetic spin-exchange interaction between the two MnII ions within each molecule.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
Cu11 complexes of 1,10-phenanthroline, disubstituted at the 2 and 9 positions or monosubstituted at the 2 position by phenyl moieties
possessingortho substituents, were prepared and investigated by spectroscopic and electrochemical methods. The electronic spectral d-d band
position varies from 14 500 to 13 200 cm−1. E.s.r. g‖ values are between 2.256 to 2.283 and A‖ between 164 to 117×10−4 cm−1. Thebis[2,9-di(o-substituted phenyl)-1,10-phenanthroline]Cu11 complexes undergo reversible one-electron electrochemical reduction (Cu11/Cu1) in the +0.536 to +0.825 V potential range versus s.c.e., whereas thebis[2-mono(o-substituted phenyl)-1,10-phenanthroline]Cu11 complexes undergo reduction in the +0.360 to +0.405 V range; the redox couple is found to be quasireversible. Emission studies
on copper(I) complexes show that onlybis[2,9-di(o-tolyl)-1,10-phen]Copper(I) complex exhibits emission properties. Emission behaviour of other structurally similar compounds
is explored.
TMC 2555 相似文献
8.
Two long-chain multidentate ligands: 2,9-di-(n-2',5',8'-triazanonyl)-1,10-phenanthroline (L^1) and 2,9-di- (n-4',7',10'-triazaundecyl)-1,10-phenanthroline (L^2) were synthesized. The hydrolytic kinetics of 2-hydroxypropyl p-nitrophenyl phosphate (HPNP) catalyzed by the complexes of L^1 or L^2 with La(Ⅲ) or Gd(Ⅲ) have been studied in aqueous solution at (298.2±0.1) K, I=0.10 mol·dm^-3 KNO3 in pH 7.5-9.1, respectively, finding that the catalytic effect of GdL^1 was the best among the four complexes for hydrolysis of HPNP. Its kLnLH-1, kLnLand pKa are 0.047 mol^-1·L·s^-1, 0.000074 mol^-1·L·s^-1 and 8.90, respectively. This paper expounded the studied result with the structure of the ligands and the properties of the metal ions, and deduced the catalysis mechanism. 相似文献
9.
Six new μ-terephthalato iron(III) binuclear complexes have been prepared and identified: [Fe2(TPHA)(L)4]-(ClO4)4 [L = 2,2′-bipyridine (bpy); 1,10-phenanthroline (phen); 4,4′-dimethyl-2,2′-bipyridine (Me2bpy); 5-methyl-1,10-phenanthroline (Me-phen); 5-chloro-1,10-phenanthroline (Cl-phen) and 5-nitro-1,10-phenanthroline (NO2-phen)]; where TPHA = the terephthalate dianion. Based on the elemental analyses, molar conductance and magnetic moments of
room-temperature measurements, and spectroscopic studies, extended TPHA-bridged structures consisting of two iron(III) ions,
each in an octahedral environment, are proposed for these complexes. The [Fe2(TPHA)(Me-phen)4](ClO4)4
(1) and [Fe2(TPHA)(phen)4](ClO4)4
(2) complexes were characterized by variable temperature magnetic susceptibility (4–300 K) measurements and the observed data
were successfully simulated by the equation based on the spin Hamiltonian operator, Ĥ = −2JŜ
1
Ŝ
2, giving the exchange integrals J = −1.05 cm−1 for (1) and J = −9.28 cm−1 for (2). This result indicates the presence of a weak antiferromagnetic spin-exchange interaction between the metal ions within each
molecule. The influence of the terminal ligand methyl substituents on magnetic interactions between the metals is also discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
10.
The reductions of [Co(CN)5NO2]3−, [Co(NH3)5NO2]2+ and [Co(NH3)5ONO]2+, by TiIII in aqueous acidic solution have been studied spectrophotometrically. Kinetic studies were carried out using conventional
techniques at an ionic strength of 1.0 mol dm−3 (LiCl/HCl) at 25.0 ± 0.1 °C and acid concentrations between 0.015 and 0.100 mol dm−3. The second-order rate constant is inverse—acid dependent and is described by the limiting rate law:- k2 ≈ k0 + k[H+]−1,where k=k′Ka and Ka is the hydrolytic equilibrium constant for [Ti(H2O)6]3+. Values of k0 obtained for [Co(CN)5NO2]3−, [Co(NH3)5NO2]2+ and [Co(NH3)5ONO]2+ are (1.31 ± 0.05) × 10−2 dm3 mol−1 s−1, (4.53 ± 0.08) × 10−2 dm3 mol−1 s−1 and (1.7 ± 0.08) × 10−2 dm3 mol−1 s−1 respectively, while the corresponding k′ values from reductions by TiOH2+ are 10.27 ± 0.45 dm3 mol−1 s−1, 14.99 ± 0.70 dm3 mol−1 s−1 and 17.93 ± 0.78 dm3 mol−1 s−1 respectively. Values of K
a
obtained for the three complexes lie in the range (1–2) × 10−3 mol dm−3 which suggest an outer-sphere mechanism. 相似文献
11.
Jonathan F. Ojo Jide Ige Grace O. Ogunlusi Olanrewaju Owoyomi Esan S. Olaseni 《Transition Metal Chemistry》2006,31(6):782-785
The kinetics of the reactions between Fe(phen)
3
2+
[phen = tris–(1,10) phenanthroline] and
Co(CN)5X3− (X = Cl, Br or I) have been investigated in aqueous acidic solutions at I = 0.1 mol dm−3 (NaCl/HCl). The reactions were carried out at a fixed acid concentration ([H+] = 0.01 mol dm−3) and the second-order rate constants for the reactions at 25 °C were within the range of (0.151–1.117) dm3 mol−1 s−1. Ion-pair constants K
ip for these reactions, taking into consideration the protonation of the cobalt complexes, were 5.19 × 104, 3.00 × 102 and 4.02 × 104 mol−1 dm−3 for X = Cl, Br and I, respectively. Activation parameters measured for these systems were as follows: ΔH* (kJ K−1 mol−1) = 94.3 ± 0.6, 97.3 ± 1.0 and 109.1 ± 0.4; ΔS* (J K−1) = 69.1 ± 1.9, 74.9 ± 3.2 and 112.3 ± 1.3; ΔG* (kJ) = 73.7 ± 0.6, 75.0 ± 1.0 and 75.7 ± 0.4; E
a
(kJ) = 96.9 ± 0.3, 99.8 ± 0.4, and 122.9 ± 0.3; A (dm3 mol−1 s−1) = (7.079 ± 0.035) × 1016, (1.413 ± 0.011) × 1017, and (9.772 ± 0.027) × 1020 for X = Cl, Br, and I respectively. An outer – sphere mechanism is proposed for all the reactions. 相似文献
12.
V. N. Kirichenko L. A. Glinskaya R. F. Klevtsova T. G. Leonova S. V. Larionov 《Journal of Structural Chemistry》1994,35(2):242-247
We have synthesized high-spin mixed-ligand Mn2+ complexes Mn(S2COR)2L where R=i−C3H7, i−C4H9; [L=1,10-phenanthroline (Phen), 2,2′-bipyridyl (2,2′-Bipy), 4,4′-bipyridyl (4,4′-Bipy)]. As solids, the compounds are stable
to oxidation by atmospheric oxygen. An X-ray structural study of the [Mn(S2COC3H7−i)2(2,2′-Bipy)] complex was carried out. The structure is composed of discrete monomeric molecules. The corrdination polyhedron
of the Mn atom is a distorted [4S+2N] octahedron. The molecules are bonded by van der Waals interactions.
Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 2, pp. 106–111, March–April, 1994.
Translated by T. Yudanova 相似文献
13.
Treatment of MeOH solutions of [Rh(cod)(fca)] (cod = 1,5-cyclooctadiene, fca = ferrocenoylacetonato) with seven derivatives of 1,10-phenanthroline (N,N), as well as with the (N,N) ligand 2,2-dipyridyl, gave [Rh(cod)(N,N)]+. The kinetics of these reactions follow the rate law: Rate = k[Rh(cod)(fca)[N,N] The temperature dependence of all the studied substitutions resulted in activation entropies, S
, more negative than –100 J K–1 mol–1 which is indicative of associative mechanisms. The pK
a's of the incoming phenanthroline derivatives were between 3.03 and 6.31 but did not influence the reaction rate to any significant extent. This implies that the rate determining step during the substitution involves Rh—O bond breaking and not Rh—N bond formation. Substitution of fca with 2,2-dipyridyl was slightly faster (k = 118 dm3 mol–1 s–1) than with the 1,10-phenanthroline derivatives (k
average = 14.2 dm3 mol–1 s–1) and may be attributed to the free rotation capability of the two pyridyl rings about the 1-1 carbon–carbon axis in 2,2-dipyridyl. 1,10-Phenanthroline cannot rotate about the corresponding carbon axis. 相似文献
14.
Dai-Zheng Liao Li-Cun Li Zong-Hui Jiang Shi-Ping Yan Peng Cheng Geng-Lin Wang Xin-Kan Yao Hong-gen Wang 《Transition Metal Chemistry》1992,17(4):356-359
Three novel heterobinuclear complexes have been prepared and identified as [Cu(oxap)Ni(L)2](ClO4)2·ξH2O, where oxap denotes theN,N′-bis(2-aminopropyl)oxamido dianion and L denotes 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen) or 5-nitro-1,10-phenanthroline
(NO2-phen). The crystal structure of [Cu(oxap)Ni(phen)2]-(ClO4)2·2H2O has been determined. Crystal data: triclinic, space group
, a=12.079 (6), b=12.409 (4), c=17.261 (8) ?, α=70.91 (2), β=86.72 (4), γ=89.19 (3)o. At room temperature, Z=2. The CuII is in a square planar environment and the NiII is in an octahedral environment. The Cu−Ni distance is 5.292 ?. The temperature dependences of the magnetic susceptibilities
of [Cu(oxap)Ni(phen)2]-(ClO4)2·2H2O and [Cu(oxap)Ni(bipy)2](ClO4)2 have been studied in the 4.2–300 K range, giving the exchange integral J=−92.4 cm−1 for bipy and J=−94.3 cm−1 for phen. These results are commensurate with antiferromagnetic interactions between the adjacent metal ions. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(7):1172-1179
The synthesis of a new Schiff base containing 1,10-phenanthroline-2,9-dicarboxaldehyde and 2-mercaptoethylamine is described. The reaction of 1,10-phenanthroline-2,9-dicarboxaldehyde with 2-mercaptoethylamine leads to 2,9-bis(2-ethanthiazolinyl)-1,10-phenanthroline (I) which undergoes rearrangement when reacted with manganese, nickel, copper or zinc ions to produce complexes of the tautomeric Schiff base 2,9-bis[2-(2-mercaptoethyl)-2-azaethene]-1,10-phenanthroline (L). The [M(L)Cl2] complexes [where M = Mn(II), Ni(II), Cu(II) and Zn(II) ions] were characterized by physical and spectroscopic measurements which indicated that the ligand is a tetradentate N4 chelating agent. 相似文献
16.
Jonathan F. Ojo Jide Ige Grace O. Ogunlusi Olanrewaju Owoyomi Esan S. Olaseni 《Transition Metal Chemistry》2006,31(3):337-339
The reactions between Fe(Phen)32+[phen = tris-(1,10) phenanthroline] and Co(CN)5X3− (X = Cl, Br or I) have been studied in aqueous acidic solutions at 25 °C and ionic strength in the range I = 0.001–0.02 mol dm−3 (NaCl/HCl). Plots of k2 versus √I, applying Debye–Huckel Theory, gave the values −1.79 ± 0.18, −1.65 ± 0.18 and 1.81 ± 0.10 as the product of charges (ZAZB) for the reactions of Fe(Phen)32+ with the chloro-, bromo- and iodo- complexes respectively. ZAZB of ≈ −2 suggests that the charge on these CoIII complexes cannot be −3 but is −1. This suggests the possibility of protonation of these CoIII complexes. Protonation was investigated over the range [H+] = 0.0001 −0.06 mol dm−3 and the protonation constants Ka obtained are 1.22 × 103, 7.31 × 103 and 9.90 × 102 dm6 mol−3 for X = Cl, Br and I, respectively. 相似文献
17.
Vesna Kuntić Dusěan Malesěev Zorica Radović Vladana Vukojević 《Monatshefte für Chemie / Chemical Monthly》2000,131(7):769-777
Summary. In the present work, rutin (3,3′ ,4′ ,5,7-pentahydrohyflavone-3-rhamnoglucoside) was determinated via a complexing reaction with a titanyloxalate anion. K2[TiO(C2O4)2] and rutin react in 50% ethanol forming a 1:2 complex in a pH range from 4.00 to 11.50, in which the TiO(C2O4)2
2− ion is linked to rutin through the 4-carbonyl and 5-hydroxyl group. The thermodynamic stability constant log β2
0 of the complex is determined to 10.80 at pH = 6.50. The change of the standard Gibbs free energy Δ G0 amounts to −61 kJċ mol−1, indicating that the process of complex formation is spontaneous. The optimal conditions for the spectrophotometric determination
of microconcentrations of rutin are at pH=6.40 and λ= 430 nm, where the complex shows an absorption maximum with a molar absorption coefficient a
430=(60±2)ċ103 dm3ċ mol−1ċ cm−1. The method is applied rutin determination from tablets.
Received January 4, 2000. Accepted (revised) February 17, 2000 相似文献
18.
The •OH and the NO2
• radicals generated pulse radiolytically in N2O-saturated aqueous solution at pH 8–8.5 oxidize Mesna to form the corresponding thiyl radicals which on reaction with thiolate
ions form an RSSR•
− type of transient with λmax = 420 nm. The rate constants for the formation of these transients were determined. In the absence of O2 at pH=6, the RS• radicals formed show an absorption maximum at 360 nm and an ε=200±50 dm3 mol−1 cm−1. The rate constant k (•OH+RSH) was 6×109 dm3 mol−1 s−1 as determined from competition kinetics. In the presence of O2 the Mesna thiyl radical was seen to rapidly add oxygen to form an RSOO• type of species with λmax = 535 nm, ε=700±50 dm3 mol−1 cm−1 and k (RS•+O2)=1.3×108 dm3 mol−1 s−1. Both the RS• and the RSOO• radicals formed by the oxidation of Mesna were able to abstract H-atoms from ascorbate ions and k(RS• +AH−)=~k(RSOO•+AH−)=~6−7×108 dm3 mol−1 s−1-. Moderately strong oxidants like CCl3OO• and the (CH3)3CO• radicals, having a reduction potential of +1.4−1.6 V vs NHE were unable to oxidize Mesna. The results thus reflect on the
pro- and anti-oxidant properties of Mesna. 相似文献
19.
A. Paul Krapcho Silvia Sparapani Amber Leenstra Joshua D. Seitz 《Tetrahedron letters》2009,50(26):3195-3747
The synthesis and structural assignments of 9-chloro-1,1-phenanthroline-2(1H)-thione and 1,10-dihydro-1,10-phenanthroline-2,9-dithione have been accomplished. The sulfur-bridged bis-1,10-phenanthroline macrocycle was readily prepared by heating the thione or equimolar amounts of the dithione and 2,9-dichloro-1,10-phenanthroline in diphenyl ether. Displacements of 2-chloro- or 2,9-dichloro-1,10-phenanthroline with N,N-dimethylethylenediamine afforded the corresponding amine and diamino analogues. An amino-substituted-2,2′-bis-1,10-phenanthroline has been prepared. 相似文献
20.
The synthesis of a new Schiff base containing 1,10-phenanthroline-2,9-dicarboxaldehyde and 2-aminobenzenethiol subunits is
described. The reaction of 1,10-phenanthroline-2,9-dicarboxaldehyde with 2-aminobenzenethiol leads to the isolation of 2,9-bis(2-benzothiazolinyl)-1,10-phenanthroline
(I) which undergoes rearrangement when reacted with cobalt, nickel, copper or zinc ions to produce complexes of the tautomeric
Schiff base 2,9-bis[2-(2-mercaptophenyl)-2-azaethene]-1,10-phenanthroline (L). The [Cu(L)ClO4][ClO4] and [M(L)X2] complexes (where M = Co(II), Ni(II) and Zn(II) and X = Br) were characterized by physical and spectroscopic measurements
which indicated that the ligand is acting probably as a tetradentate N4 chelating agent. 相似文献