The syntheses of the aliphatic bidentate guanidine-amine-hybrid ligands DMEGdmae (L1), TMGdmae (L2), TMGdeae (L3) and DPipGdmae (L4) as well as the reaction of their Cu(I) complexes with molecular oxygen (monitored by UV-Vis spectroscopy) are reported. The molecular structures of 10 bis(μ-hydroxo) dicopper complexes based on these ligands are described. The solid state structures of [Cu2(μ-OH)2(DMEGdmae)2]X2 (X− = I− (1), CF3SO3− (2), SbF6− (3), PF6− (4)), [Cu2(μ-OH)2(TMGdmae)2]X2 (X− = I− (5), CF3SO3− (6)), [Cu2(μ-OH)2(TMGdeae)2]Cu2I4 (7) and [Cu2(μ-OH)2(DPipGdmae)2]X2 (X− = CF3SO3− (8), SbF6− (9), PF6− (10)) show a square-planar distorted coordination of the copper(II) ion. The bis(μ-hydroxo) dicopper complex 1 exhibits a Cu···Cu distance of 2.860(1) Å, which is one of the smallest observed for hydroxo-bridged copper compounds so far. The influence of the anion on the structure of the bis(μ-hydroxo) dicopper(II) unit is analyzed for the reported complexes and a literature overview with emphasis on the structural characteristics of the Cu2O2 moiety of bis(μ-hydroxo) dicopper(II) and bis(μ-oxo) dicopper(III) is given. 相似文献
Two phenoxo bridged dinuclear Cu(II) complexes, [Cu2L2(NO2)2] (1) and [Cu2L2(NO3)2] (2) have been synthesized using the tridentate reduced Schiff-base ligand 2-[(2-dimethylamino-ethylamino)-methyl]-phenol (HL). The complexes have been characterized by X-ray structural analyses and variable-temperature magnetic susceptibility measurements. The structures of the two compounds are very similar having the same tridentate chelating ligand (L) and mono-dentate anionic ligand nitrite for 1 and nitrate for 2. In both complexes Cu(II) is penta-coordinated but the square pyramidal geometry of the copper ions is severely distorted (Addison parameter (τ) = 0.33) in 1 while the distortion is quite small (average τ = 0.11) in 2. These differences have marked effect on the magnetic properties of two compounds. Although both are antiferromagnetically coupled, the coupling constants (J = −140.8 and −614.7 cm−1 for 1 and 2, respectively) show that the coupling is much stronger in 2. 相似文献
A new method for the synthesis of metal dithiolenes with alkyl-substituted chelate rings has been investigated. The utility of the protected ene-1,2-dithiolate 3,4-bis-triisopropylsilanyl-sulfanyl-hex-3-ene as a precursor in reactions with metal halide and oxyhalide complexes was examined. Reaction conditions involve a 2:1 or 3:1 mol ratio of reactants in acetonitrile/THF or toluene at 50–80 °C for 24–36 h. Complex formation was observed as a result of Si–S bond cleavage by bound or free halide and oxo ligands. Members of four major structural families of dithiolene complexes were prepared in ca. 25–70% yields, including planar [Ni(S2C2Et2)2], square pyramidal [MI(S2C2Et2)2] (M = Co, Fe), [Fe(py)(S2C2Et2)2]1−, and [ReO(S2C2Et2)2]1−, centrosymmetric [M2(S2C2Et2)4]2− (M = Co, Mn), [M(S2C2Et2)3]1− (M = V, Nb), and trigonal prismatic [M(S2C2Et2)3] (M = Mo, W). Seven X-ray structure proofs are provided. It is concluded that the method is feasible and potentially extendable to other ring substituents, whose primary effects are on solubility and modulation of redox potentials. 相似文献
Seven diiridium(II) complexes were synthesized by ligand substitution reactions of [Ir2(μ-O2CMe)2Cl2(CO)2] (1) and [Ir2(μ-O2CMe)2Cl2(CO)2(py)2] (2).The reaction of 2 with the silver salt of a less coordinating anion, AgSbF6, gave a cationic complex [Ir2(μ-O2CMe)2Cl(CO)2(py)3]SbF6 (3).A tricarbonyl cationic complex [Ir2(μ-O2CMe)2(CO)3Cl(py)2]SbF6 (4) was obtained under a CO atmosphere.Complex 2 reacted with AgO2CCF3 to give [Ir2(μ-O2CMe)2Cl(O2CCF3)(CO)2(py)2] (5) in toluene.[Ir2(μ-hiq)2(CO)2Cl2] (Hhiq = 1-hydroxyisoquinoline, 6) was synthesized by the bridging-ligand substitution of 1 with Hhiq.Its axial adducts [Ir2(μ-hiq)2Cl2(CO)2L2] (L = Mepy (4-methylpyridine), 7 or PPh3, 8) were synthesized by addition of the ligands to a suspension of 6.In the structures of 7 and 8, two iridium atoms are bridged by two hiq ligands in a head-to-tail arrangement.The reaction of 1 with Hmhp (2-hydroxy-4-methylpyridine) led to triply bridged [Ir2(μ-mhp)3(CO)2Cl(Hmhp)] (9).In complex 9, all the mhp ligands bridge between the Ir atoms in a head-to-head manner.The Ir-Ir distances of 3, 4, 5, 7 and 8 are 2.6047(7), 2.6216(9), 2.5899(9), 2.5933(5) and 2.634(2) Å, respectively, which are similar to those observed in[Ir2(μ-O2CMe)2Cl2(CO)2L2]. The Ir-Ir distance of 2.5512(4) Å in 9 is shorter than in the other complexes. 相似文献
A series of acetato complexes of molybdenum(V), based on the singly metal–metal bonded {Mo2O4}2+ structural fragment, has been prepared. A dinuclear (PyH)3[Mo2O4Cl4(OOCCH3)] · CH3CN (1) (PyH+ = pyridinium cation, C5H5NH+) was obtained upon the reaction of (PyH)5[MoOCl4(H2O)]3Cl2 with the equimolar solution of pyridine and acetic acid in acetonitrile at ambient conditions. The acetato ligand in 1 is coordinated to a pair of molybdenum atoms in a syn–syn bidentate bridging manner. (PyH)n[MoOBr4]n afforded in an analogous synthetic procedure a tetranuclear cluster, [Mo4O8(OOCCH3)3(OH)Py4] · 1/2CH 3CN · 1/2H2O (3), with a novel core which may be envisioned as the acetate- and hydroxide-assisted assembly of {Mo2O4}2+ building blocks. Its structure is presented in terms of known tetranuclear clusters which are also composed of two {Mo2O4}2+ units. The acetato ligands in 3 adopted apart from bidentate bridging binding modes also a monodentate one. Partial substitution of chlorido ligands in (PyH)3[Mo2O4Cl4(OOCCH3)] · CH3CN (1) with pyridine resulted in a neutral [Mo2O4Cl(OOCCH3)Py3] · PriOH · Py (2) which retained the original acetate coordination. The title compounds were fully characterized by X-ray diffraction studies and infrared vibrational spectroscopy. 相似文献
The reactions of [RuHCl(CO)(PPh3)3] with resorcinol bis(phosphinite) pincer ligands lead to complexes of the general formula [RuCl(PCP)(CO)(PPh3)]; the crystal structure of one example has been determined. The structures of the bulky resorcinol 2-methyl-4,6-di-tert-butyl resorcinol and its mono-diisopropylphosphinite derivative were also determined. Reactions of [RuCl2(PPh3)3] with resorcinol bis(phosphinite) ligands yield complexes of the type [RuCl(PCP)(PPh3)], while the reaction of C6H-2-Me-4,6-tBu2-1,3-(OPPh2) with [RuHCl(CO)(PPh3)3] provides a PCP–pincer complex in which the ligand has undergone 2-methyl C–H activation. 相似文献
The new ligand N,N′-(2-methyl-2-(2-pyridyl)propan-1,3-diyl)bis(tetramethylguanidine) (L) and its four-coordinate, distorted square-planar copper(II) complex [CuLCl2] (1) were synthesized and structurally characterized. Similarly, bis(μ-OH)dicopper(II,II) complex [Cu2L2(OH)2](OTf)2 (2) was synthesized and structurally characterized. The pyridyl group in L does not coordinate in either 1 or 2. New examples of μ-η2:η2-disulfido dicopper(II,II) complexes were synthesized by treating a copper(I) complex of either L or L′ [L′ = 2′,2′-(propane-1,3-diyl)bis(1,1,3,3-tetramethylguanidine)] with elemental sulfur. [Cu2L2(S2)](PF6)2 (3) and [Cu2(S2)](PF6)2 (4) were both structurally characterized, and both structures have two copper(II) ions bridged by a disulfido ligand in a μ-η2:η2-manner. The ligands L and L′ coordinate in a bidentate fashion (like 1 and 2, the pyridyl ring does not coordinate in 3), and the geometry around the copper ions in 3 and 4 is distorted square planar. The metrical parameters of 3 and 4 were found to be similar to other μ-η2:η2-disulfido dicopper(II,II) complexes, and the Cu-S and Cu···Cu distances are among the shortest reported for this class of copper disulfide dimers. 相似文献
Two phenoxido bridged dinuclear Cu(II) complexes, [Cu2(L1)2(NCNCN)2] (1) and [Cu2(L2)2(NCNCN)2]·2H2O (2) have been synthesized using the tridentate reduced Schiff-base ligands 2-[1-(2-dimethylamino-ethylamino)-ethyl]-phenol (HL1) and 2-[1-(3-methylamino-propylamino)-ethyl]-phenol (HL2), respectively. The complexes have been characterized by X-ray structural analyses and variable-temperature magnetic susceptibility measurements. Both the complexes present a diphenoxido bridging Cu2O2 core. The geometries around metal atoms are intermediate between trigonal bipyramid and square pyramid with the Addison parameters (τ) = 0.57 and 0.49 for 1 and 2, respectively. Within the core the Cu–O–Cu angles are 99.15° and 103.51° and average Cu–O bond distances are 2.036 and 1.978 Å for compounds 1 and 2, respectively. These differences have marked effect on the magnetic properties of two compounds. Although both are antiferromagnetically coupled, the coupling constants (J = −184.3 and −478.4 cm−1 for 1 and 2, respectively) differ appreciably. 相似文献
Two oxime-functionalized diazamesocyclic derivates, namely, N,N′-bis(acetophenoneoxime)-1,4-diazacycloheptane (H2L1) and N,N′-bis(acetophenonoxime)-1,5-diazacyclooctane (H2L2), have been prepared and characterized. Both ligands (obtained in the hydrochloride form) can form stable metal complexes with CuII and NiII salts, the crystal structures of which were determined by X-ray diffraction technique. The reactions of H2L1 with Cu(ClO4)2 and Ni(ClO4)2 afford a penta-coordinated mononuclear complex [Cu(H2L1)Cl] · ClO4 (1) and a four-coordinated monomeric [Ni(HL1)] · ClO4 (2), in which the ligand is monodeprotonated. The ligand H2L2 also forms a quite similar mononuclear [Ni(HL2)] · ClO4 complex with Ni(ClO4)2, according to our previous work. However, reactions of different CuII salts [Cu(ClO4)2, CuCl2 and Cu(NO3)2 for 3, and CuSO4 for 4] with H2L2 in the presence of NaClO4 yield two unusual mono-μ-Cl dinuclear CuII complexes [Cu2(HL2)2Cl] · (ClO4) (3), and [Cu2(H2L2)(HL2)Cl] · (ClO4)2 · (H2O)(4). These results indicate that the resultant CuII complexes (1, 3 and 4) are sensitive to the backbones of diazamesocycles and even auxiliary anions. 相似文献
The mechanism of ruthenium-bis(phosphine) catalyzed enantioselective hydrogenation of olefins was examined using [Ru((R)-BINAP)(H)(MeCN)n(sol)3 − n]BF4 (n = 0–3, sol = solvent used in reaction) as catalyst. Tiglic and angelic acids were used as standard α,β-unsaturated acid substrates; (Z)-methyl α-acetamidocinnamate and dimethyl itaconate were used as standard α,β-unsaturated ester substrates. Isotopic labeling studies (deuterium scrambling) indicate that two distinct mechanisms are in operation for α,β-unsaturated acids versus α,β-unsaturated esters. In each case, 5-membered metallocycle intermediates are formed via olefin-hydride insertion. The mechanisms, however, deviate primarily in the activation of dihydrogen, which is strongly affected by the nature of the substrate. Hydrogenation of α,β-unsaturated acids proceed via heterolytic cleavage of dihydrogen, whereas hydrogenation of α,β-unsaturated esters proceed via homolytic cleavage of dihydrogen. A full discussion of the mechanisms is presented. 相似文献
The series of complexes [Mn(IV)(X-SALPN)(2-O)]2, 1: X=5-OCH3; 2: X=H; 3: X=5-Cl; 4: X=3,5-diCl; 5: X=5-NO2, contain [Mn2O2]4+ cores with Mn-Mn separations of 2.7 . These molecules can be protonated to form [Mn(IV)(X-SALPN)(2-O,OH)]2+ in which a bridging oxide is protonated. The pKa values for the series of [Mn(IV)(X-SALPN)(2-O,OH)]2+ track linearly versus the shift in redox potential with a slope of 84 mV/pKa. This observation suggests that the [Mn2O2]4+ core can be considered as a unit in which the free energy of protonation is directly related to the ability to reduce the Mn(IV) ion. The marked sensitivity of the reduction potential to the presence of protons presents a mechanism in which an enzyme can control the oxidizing capacity of an oxo manganese cluster by the degree and timing of oxo bridge protonation.Abbreviations AnH+CF3SO3-
anilinium triflate
- DMA
N,N-dimethyl acetamide
- H2SALPN
1,3-bis(salicylideneiminato)propane
- H2(5-Cl-SALPN)
1,3-bis(5-chlorosalicylideneiminato)propane;
- H2(3,5-diCl-SALPN)
1,3-bis(3,5-dichlorosalicylideneiminato)propane
- H2(5-NO2-SALPN)
1,3-bis(5-nitorosalicylideneiminato)propane
- H2(5-OMe-SALPN)
1,3-bis(5-methoxysalicylideneiminato)propane
- LuH+CF3SO3-
2,4-lutidinium triflate
- ME3NH+Ph4B-
trimethylammonium tetraphenylborate
- OEC
oxygen evolving complex
- PyH+ClO4-
pyridinium perchlorate
- SCE
saturated calomel electrode 相似文献
The interactions of five bis(bipyridyl) Ru(II) complexes of pteridinyl-phenanthroline ligands with calf thymus DNA have been studied. The pteridinyl extensions were selected to provide hydrogen-bonding patterns complementary to the purine and pyrimidine bases of DNA and RNA. The study includes three new complexes [Ru(bpy)(2)(L-pterin)](2+), [Ru(bpy)(2)(L-amino)](2+), and [Ru(bpy)(2)(L-diamino)](2+) (bpy is 2,2'-bipyridine and L-pterin, L-amino, and L-diamino are phenanthroline fused to pterin, 4-aminopteridine, and 2,4-diaminopteridine), two previously reported complexes [Ru(bpy)(2)(L-allox)](2+) and [Ru(bpy)(2)(L-Me(2)allox)](2+) (L-allox and L-Me(2)allox are phenanthroline fused to alloxazine and 1,3-dimethyalloxazine), the well-known DNA intercalator [Ru(bpy)(2)(dppz)](2+) (dppz is dipyridophenazine), and the negative control [Ru(bpy)(3)](2+). Reported are the syntheses of the three new Ru-pteridinyl complexes and the results of calf thymus DNA binding experiments as probed by absorption and fluorescence spectroscopy, viscometry, and thermal denaturation titrations. All Ru-pteridine complexes bind to DNA via an intercalative mode of comparable strength. Two of these four complexes-[Ru(bpy)(2)(L-pterin)](2+) and [Ru(bpy)(2)(L-allox)](2+)-exhibit biphasic DNA melting curves interpreted as reflecting exceptionally stable surface binding. Three new complexes-[Ru(bpy)(2)(L-diamino)](2+), [Ru(bpy)(2)(L-amino)](2) and [Ru(bpy)(2)(L-pterin)](2+)-behave as DNA molecular "light switches." 相似文献
Semi-empirical quantum mechanics calculations using AM1 (Austin Method 1) were carried out for various host-guest combinations of α-cyclodextrin and mono-halogen benzoic acids. The energetically favorable inclusion structures were identified. The AM1 results show that α-cyclodextrin complexes with mono-halogen benzoic acid acids (where the halogen is chlorine, bromide, iodine) as guest compounds are more stable in the “head first” position than in the “tail-first” position for meta and para isomers while ortho mono-halogen benzoic acids complexes with α-cyclodextrin are more stable in “tail-first” position. The calculated structures were found to be in good agreement with those obtained from crystalographic databases.
相似文献
Substituted η3-butadienyl complexes containing amide-armed crowns (X) of general formula [MoCl(CO)2(η3-CH2C(COX)CCH2)(phen)]n (phen=1,10-phenanthroline) were prepared and investigated for their ability to extract alkali metal ions from a mixed phase system. Reaction of the chlorocarbonyl precursor (1) with 1-aza-15-crown-5, 4′-aminobenzo-15-crown-5, 2-aminomethyl-15-crown-5, 4′-aminobenzo-18-crown-6 or 2-aminomethyl-18-crown-6 gave monomeric complexes (n=1), and addition of sodium tetraphenylboron to the 15-crown-5-substituted complexes gave the corresponding sodium salts. Dinuclear complexes (n=2) were formed by reaction of 1 and 1,7-diaza-15-crown-5 or 4,4′(5′)-diaminobenzo-15-crown-5. Comparison of amidobenzo- and 2-amidomethyl-15-crown-5-substituted complexes showed enhanced sodium transport properties for the latter, and spectroscopic and molecular modeling studies suggested complexation occurred by concerted action of the amide and crown. 相似文献
During the investigation of the development of insulin-mimetic zinc(II) complexes with a blood glucose-lowering effect in experimental diabetic animals, we found a potent bis(maltolato)zinc(II) complex, Zn(ma)2, exhibiting significant insulin-mimetic effects in a type 2 diabetic animal model. By using this Zn(ma)2 as the leading compound, we examined the in vitro and in vivo structure–activity relationships of Zn(ma)2 and its related complexes. The in vitro insulin-mimetic activity of these complexes was determined by the inhibition of free fatty acid release and the enhancement of glucose uptake in isolated rat adipocytes treated with epinephrine. A new Zn(II) complex with allixin isolated from garlic, Zn(alx)2, exhibited the highest insulin-mimetic activity among the complexes analyzed. The insulin-mimetic activity of the Zn(II) complexes examined strongly correlated (correlation coefficient=0.96) with the partition coefficient (logP) of the ligand, indicating that the activity of Zn(ma)2-related complexes depends on the lipophilicity of the ligand. The blood glucose-lowering effects of Zn(alx)2 and Zn(ma)2 were then compared, and both complexes were found to normalize hyperglycemia in KK-Ay mice after a 14-day course of daily intraperitoneal injections. However, Zn(alx)2 improved glucose tolerance in KK-Ay mice much more than did Zn(ma)2, indicating that Zn(alx)2 possesses greater in vivo anti-diabetic activity than Zn(ma)2. In addition, Zn(alx)2 improved leptin resistance and suppressed the progress of obesity in type 2 diabetic KK-Ay mice. On the basis of these observations, we conclude that the Zn(alx)2 complex is a novel potent candidate for the treatment of type 2 diabetes mellitus.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00775-004-0590-8 相似文献
Two novel bis(oxo)-bridged dinuclear manganese(IV) complexes with the binucleating ligand o-phenylenebis(oxamate) (opba), formulated as (Me4N)4[Mn2O2(opba)2] (1a) and (Me4N)2(Ph4P)2[Mn2O2(opba)2] · 8H2O (1b), have been synthesized and characterized structurally and magnetically. Like the parent complex (Ph4P)4[Mn2O2(opba)2] · 4H2O (1c), they possess unique Mn2(μ-O)2 bridging cores with two additional o-phenylenediamidate bridges which lead to exceptionally short Mn-Mn distances (2.63-2.67 Å) and fairly bent Mn-O-Mn angles (93.8-95.5°). Complexes 1a-c show a moderate to strong antiferromagnetic coupling between the two high-spin MnIV ions through the bis(oxo)bis(o-phenylenediamidate) quadruple bridge (−J = 70-164 cm−1; H = −JS1 · S2). Along this series, the −J values increase with the shortening of the Mn-Mn distance and/or the lessening of the Mn-O-Mn angle. Electronic structure calculations on model complexes reproduce the observed dependence of −J with the Mn-O-Mn angle at short intermetallic distances, and reveal that the magnetic coupling is dominated by the in-plane 3dx2-y2 type superexchange pathway via the oxo bridges with a small but nonnegligible contribution from direct 3dx2-y2 type Mn-Mn σ-bond. 相似文献
The complexes [Cu(samen)Cu(L)] and [Cu(samen)Ni(L)2] (Lbpy, phen) have been synthesized by the reaction of sodium N,N′-ethylenedisalicylamidatocuprate(II) pentahydrate (Na2- [Cu(samen)]·5H2O), a divalent metal ion, and 2,2′- dipyridyl or 1,10-phenanthroline. Cryomagnetic data for the CuCu complexes did not fit the Bleaney- Bowers equation; but the data did fit a modified Bleaney-Bowers equation with a large negative J and a significant negative θ, suggesting that a considerable magnetic interaction operates between essentially planar [Cu(samen)Cu(L)] molecules. The magnetisms of the CuNi complexes were well interpreted in terms of the susceptibility equation based on the Heisenberg model. An antiferromagnetic spin-exchange interaction (J= −13∼−14 cm−1) was suggested between the metal ions. 相似文献
In this paper,we define the new idea of triangular cubic hesitant fuzzy number(TCHFN).We discuss some basic operational laws of triangular cubic hesitant fuzzy number and hamming distance of TCHFNs.We introduce the new concept of triangular cubic hesitant TOPSIS method.Furthermore,we extend the classical cubic hesitant the technique for order of preference by similarity to ideal solution(TOPSIS)method to solve the Multi-Criteria decision-making(MCDM)method based on triangular cubic hesitant TOPSIS method.The new ranking method for TCHFNs is used to rank the alternatives.Finally,an illustrative example is given to verify and demonstrate the practicality and effectiveness of the proposed method. 相似文献
The displacement of tetrahydrothiophen (tht) in [Au(tht)2]ClO4 by neutral ligands gives bi-, tri- or tetra-coordinated complexes of the type [Au- (py)2]ClO4, [(tht)AuPPh2NHPPh2Au(tht)] (ClO4)2, [LAu(LL)]ClO4 (L=tht, PPh3; LL=bipy, phen) or [AuL4]ClO4 (L=PPh3, AsPh3 or SbPh3). The reaction between [Au(tht)2]ClO4 and (Bu4N)[AuR2] (R=C6F5, C6Cl5, C6F3H2) yields RAu(tht). The 197Au Mössbauer spectrum of [LAu(LL)]ClO4 establishes it as a tri-coordinated species, albeit with an asymmetrically linked bidentate ligand. 相似文献