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1.
Xavier FR Peralta RA Bortoluzzi AJ Drago V Castellano EE Haase W Tomkowicz Z Neves A 《Journal of inorganic biochemistry》2011,105(12):1740-1752
In this work we report on the synthesis, crystal structure, and physicochemical characterization of the novel dinuclear [FeIIICdII(L)(μ-OAc)2]ClO4·0.5H2O (1) complex containing the unsymmetrical ligand H2L = 2-bis[{(2-pyridyl-methyl)-aminomethyl}-6-{(2-hydroxy-benzyl)-(2-pyridyl-methyl)}-aminomethyl]-4-methylphenol. Also, with this ligand, the tetranuclear [Fe2IIIHg2II(L)2(OH)2](ClO4)2·2CH3OH (2) and [FeIIIHgII(L)(μ-CO3)FeIIIHgII(L)](ClO4)2·H2O (3) complexes were synthesized and fully characterized. It is demonstrated that the precursor [FeIII2HgII2(L)2(OH)2](ClO4)2·2CH3OH (2) can be converted to (3) by the fixation of atmospheric CO2 since the crystal structure of the tetranuclear organometallic complex [FeIIIHgII(L)(μ-CO3)FeIIIHgII(L)](ClO4)2·H2O (3) with an unprecedented {FeIII(μ-Ophenoxo)2(μ-CO3)FeIII} core was obtained through X-ray crystallography. In the reaction 2 → 3 a nucleophilic attack of a FeIII-bound hydroxo group on the CO2 molecule is proposed. In addition, it is also demonstrated that complex (3) can regenerate complex (2) in aqueous/MeOH/NaOH solution. Magnetochemical studies reveal that the FeIII centers in 3 are antiferromagnetically coupled (J = − 7.2 cm− 1) and that the FeIII-OR-FeIII angle has no noticeable influence in the exchange coupling. Phosphatase-like activity studies in the hydrolysis of the model substrate bis(2,4-dinitrophenyl) phosphate (2,4-bdnpp) by 1 and 2 show Michaelis-Menten behavior with 1 being ~ 2.5 times more active than 2. In combination with kH/kD isotope effects, the kinetic studies suggest a mechanism in which a terminal FeIII-bound hydroxide is the hydrolysis-initiating nucleophilic catalyst for 1 and 2. Based on the crystal structures of 1 and 3, it is assumed that the relatively long FeIII…HgII distance could be responsible for the lower catalytic effectiveness of 2. 相似文献
2.
The reaction of Ni(ClO4)2·6H2O with 3,5-dichloro-2-hydroxy-benzylaminoacetic acid (H2dchaa), NaN3 and triethylamine in methanol solution or water solution under solvothermal methods leads to the formation of two completely different NiII compounds: [HN(C2H5)3]8·[Ni4(dchaa)4(N3)4]2 (1) and [HN(C2H5)3]2·[Ni3(dchaa)4(H2O)4]2·(H2O)2 (2). The complexes 1 and 2 have been characterized by elemental analyses, IR spectra and single-crystal X-ray diffraction. Structure analyses reveal that complex 1 is a cubane cluster, while the complex 2 is a linear trinuclear cluster. The magnetic investigation shows that complexes 1 and 2 exhibit a ferromagnetic coupling between NiII ions. Ac susceptibilities of 1 and 2 reveal no frequency-dependent out-of-phase signals and the corresponding magnetic properties were discussed. 相似文献
3.
Zhi-Guo Gu You Song Cheng-Hui Li Yi-Zhi Li Xiao-Zeng You 《Inorganica chimica acta》2005,358(13):4057-4061
A new tri-cyanometalate building block for heterometallic complexes, [PPh4]2[FeII(Tpms)(CN)3] (2) (PPh4 = tetraphenylphosphonium; Tpms = tris(pyrazolyl) methanesulfonate), has been prepared. Using it as a building block, a one-dimensional chain compound, {[FeII(Tpms)(CN)3][MnII(H2O)2( DMF)2]} · DMF (3), has been synthesized and structurally characterized. The magnetic properties of 3 correspond to a ferromagnetic chain with weak long-range superexchanged magnetic interaction between the high-spin manganese(II) ions. 相似文献
4.
Andrew D. Burrows Christopher G. Frost Luke L. Keenan Teresa L. Savarese 《Inorganica chimica acta》2011,366(1):303-256
The product from the reaction between Cd(NO3)2·4H2O and 1,3,5-benzenetricarboxylic acid (H3btc) in DMF at 95 °C depends on the reaction time, with [Cd(Hbtc)(H2O)2] 1 and [Cd(Hbtc)(DMF)2] 2 isolated after heating for 10 min, the latter after standing the solution for 1-2 weeks at room temperature. [Cd3(btc)2(H2O)9]·4H2O 3 was isolated after heating for 1 h, whereas [Cd12(btc)8(DMF)14(OH2)2]·1.5DMF 4 was isolated after heating for 2 days. Compounds 1 and 3 have been previously reported, whereas 2 and 4 are both new. Compound 2 adopts a two-dimensional sheet structure, with the coordinated DMF ligands projecting from both sides of the sheets, whereas 4 has a complex three-dimensional structure related to the fsc net. When the reaction was repeated in the presence of pyrazine (pyz), the product [Cd(Hbtc)(pyz)(DMF)]·DMF 5 was isolated as a minor compound. Compound 5 has a two-dimensional structure, with Cd-Hbtc zig-zag chains linked into sheets through the pyrazine ligands. 相似文献
5.
The derivatives of Cu(HCOO)2 · 4H2O with 2-(phenylamino)pyridine and 2-(methylamino)pyridine, [Cu2(μ-HCOO)4(PhNHpy)2] (1), [Cu2(μ-HCOO)4(MeNHpy)2] (2) and Cu(HCOO)2(MeNHpy)2 (3), have been synthesized and characterized. Compounds 1 and 2 show the paddle-wheel structure of [Cu2(μ-HCOO)4L2], with four syn-syn bridging formato groups and two molecules of PhNHpy or MeNHpy coordinated to the axial positions, respectively. Intramolecular hydrogen bonds are formed in both cases: two in each dimer of 1 and four in the dimer of compound 2. The dimer units are oriented in two different directions. Dimers with the same orientation form rows along the “c” and the “a” axis in compounds 1 and 2, respectively, with a π-π stacking of the pyridine rings. In compound 1, an intercalation of the phenyl rings of contiguous rows of dimers gives rise to a succession of phenyl rings at a distance of 4.38 Å and an angle of 30.44° between alternate rings. They are antiferromagnetic. Signals of the triplet state are observed in their EPR spectra and the zero-field splitting parameter has been determined. Compound 3 obeys the Curie-Weiss law and the magnetic results indicate the absence of magnetic interaction between Cu(II) atoms. 相似文献
6.
Reactions of FeII, CoII, NiII, and ZnII salts with 6-quinolinecarboxylic acid (HL) under the hydrothermal conditions afford three monomeric complexes [M(L)2(H2O)4] (M = FeII for 1, CoII for 2, and NiII for 3) and a 1-D polymeric species {[Zn(L)2(H2O)] · H2O}n (4). The crystal structures of the ligand HL and these four complexes have been determined by using the X-ray single-crystal diffraction technique. The results suggest that complexes 1-3 are isostructural, displaying novel 3-D pillar-layered networks through multiple intermolecular hydrogen bonds, whereas in coordination polymer 4, the 1-D comb-like coordination chains are extended to generate a hydrogen-bonded layer, which is further reinforced via aromatic stacking interactions. Solid-state properties such as thermal stability and fluorescence emission of the polymeric ZnII complex 4 have also been investigated. 相似文献
7.
Montserrat Barquín Nerea Cocera Liher Larrínaga José M. Seco 《Inorganica chimica acta》2010,363(1):127-133
By the reactions of Cu(AcO)2·H2O and Cu(HCOO)2·4H2O with 4,4′-dimethyl-2,2′-bipyridine and 5,5′-dimethyl-2,2′-bipyridine the compounds [Cu(AcO)2(4,4′-Me2-2,2′-bipy)]·1/2H2O (1), [Cu(AcO)2(5,5′-Me2-2,2′-bipy)(H2O)] (2), [Cu(HCOO)(μ-HCOO)(4,4′-Me2-2,2′-bipy)]n·nH2O (3) and [Cu(HCOO)(μ-HCOO)(5,5′-Me2-2,2′-bipy)]n·2nH2O (4) were obtained. In the acetate complexes, 1 and 2, the geometry around copper is distorted octahedral and square pyramidal, respectively. Dimeric units of different geometry are formed in both cases through hydrogen bonds in which non-coordinated (in 1) and coordinated (in 2) water molecules are involved. The structures of 3 and 4 consist of polymeric monodimensional chains of square pyramidal copper units linked by axial-equatorial syn-anti (3) or anti-anti (4) bridging formate groups. Water molecules form hydrogen bonds with formate groups of the same chain in compound 3. In compound 4 the water molecules link the polymeric contiguous chains of complex through hydrogen bonds with oxygen atoms of formate groups and they are also linked between them, forming monodimensional water chains which run parallel to the complex chains. Sheets parallel to the ac plane are formed by alternating chains of water and polymeric complex. Magnetic properties and EPR spectra for these compounds have been studied. 相似文献
8.
Rampal Pandey Prashant Kumar Sanjay Kumar Singh Daya Shankar Pandey 《Inorganica chimica acta》2011,376(1):195-206
The synthesis and characterization of novel coordination polymers [Co(HCCB)(H2O)2]n (1), [Zn(HCCB)(H2O)2]n (2), {[Cd(HCCB)2]·0.5[Cd(μ-H2O)(H2O)4]2}n (3) and [Cu(HCCB)(H2O)2]n (4) based on 3-(carboxymethylamino)-4-chlorobenzoic acid (H3CCB) and mononuclear complexes [Cu(HBCCB)(H2O)]·H2O (5), [Co(HBCCB)(H2O)]·H2O (6), [Zn(HBCCB)(H2O)] (7) and [Cd(HBCCB)(H2O)] (8) containing 3-bis(carboxymethylamino)-4-chlorobenzoic acid (H3BCCB) have been described. The compounds under investigation have been characterized by elemental analyses, spectral studies and structures of 1-3 and 5 determined crystallographically. Structural data of 1 and 2 revealed that the deprotonated HCCB2− bridges metal centers leading to a double stranded 1D chain. On the other hand, the HCCB2− coordinated thorough carboxylate oxygen and amino nitrogen in 3 to afford a 1D chain whose charge neutrality is maintained by inclusion of aqua-bridged dimer [{Cd(μ-H2O)(H2O)4}2]4+. Strong Cu?Cl interaction (2.754 Å) in 5 imposes a coordination geometry that is half-way between the square planar and square pyramidal. The H3CCB, H3BCCB and 1-3 and 5 are fluorescent at rt. Thermal studies (TG and DSC) on 1-3 suggested higher stability of 2 relative to 1 and 3 [ΔHf (kcal/mol), ΔSf = 152.17, 0.60, 1; 195.56: 0.86, 2; 69.33:0.36, 3]. 相似文献
9.
Yuan-Yuan Hui Juan Song Hong-Liang Yao Xiao-Le Yang Qing-Ran Wu Meng-Lin Yang Gang-Lin Xue 《Inorganica chimica acta》2010,363(13):3238-3243
The new β-diketone-functionalized pyridinecarboxylate ligand 2-(3-oxo-3-phenyl-propionyl)-6-pyridinecarboxylic acid (H2L) has been synthesized and fully characterized. Its tetranuclear and trinuclear nickel(II) coordination compounds [Ni4L4(DMF)(H2O)3]·2.5DMF·3H2O (1) and [Ni3L2(OAc)2(DMF)2 (H2O)2]·DMF·H2O (2) have also been synthesized and characterized by single crystal X-ray diffraction. Compound 1 has a [2 × 2] molecular grid structure and 2 is a trinuclear structure. The magnetic properties study of 1 and 2 revealed the intramolecular antiferromagnetic exchange coupling between the Ni(II) ions exists. 相似文献
10.
I. Ravikumar 《Inorganica chimica acta》2010,363(12):2886-520
Syntheses and crystal structures of tren-based amide, L1, N,N′,N″-tris[(2-amino-ethyl)-4-nitro-benzamide] and L2, N,N′,N″-tris[(2-amino-ethyl)-2-nitro-benzamide] are reported and compared with previously published tripodal amide receptor L3, N,N′,N″-tris[(2-amino-ethyl)-3-nitro-benzamide]. The crystallographic results show intramolecular and intermolecular hydrogen-bonding interactions between two arms of the tripodal receptor and two other adjacent molecules in cases of L1 and L2 whereas in addition to the above interactions an aromatic π···π stacking among tripodal arms is also observed in L3. Receptors L1, L2 and L3 having electron withdrawing -NO2 substituted (para, ortho and meta, respectively) phenyl moieties are explored toward their solution state anion binding properties and selectivity studies. The substantial changes in chemical shifts are observed for the amide protons (-NH) and aromatic protons (-CH) with F− and Cl− in cases of L1 and L3, and only with F− for L2, indicating the participation of -NH and -CH protons in the solution state binding events. Binding constants for the above cases are calculated by 1H NMR titration upon monitoring the -NH signal. Receptor L2 shows exclusive selectivity toward F− in dimethyl sulfoxide (DMSO). The structural aspects of binding I−, ClO4− and SiF62− with the monoprotonated L1, L1H+·I−·DMF (1), L1H+·ClO4−·DMF (2) and L1H+·0.5SiF62−·H2O (3), respectively are examined crystallographically. Anion binding with multiple receptor units is observed via amide N-H···anion as well as aryl C-H···anion hydrogen-bonding interactions in all the complexes as observed in cases of previously reported crystal structures of anionic complexes of protonated L3. The aryl group having nitro functionality that contributes to solution state anion binding with the neutral receptor and solid state coordination in complexes 1-3 through CH···anion interactions is noteworthy. 相似文献
11.
Yue Zhao 《Inorganica chimica acta》2011,377(1):138-143
Four new coordination complexes [Cd(DPBA-3)2(H2O)2](ClO4)2·2H2O (1), [Cd(DPBA-3)(DMF)(NO3)2]·DMF (2), [Cd3(DPBA-3)2(SCN)6]·2DMF·4H2O (3) and [Zn(DPBA-3)(SCN)2] (4) [DPBA-3 = N,N′-di(pyridin-3-yl)pyridine-3,5-dicarboxamide] have been synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. Complexes 1, 3 and 4 exhibit three different types of one-dimensional (1D) chain structures constructed by the metal ions and DPBA-3 ligands, and the Cd(II)-DPBA-3 1D chains in 3 are further linked by bridging SCN− ligands to afford a three-dimensional (3D) framework. Complex 2 possesses a (6,3) two-dimensional (2D) layer structure. In 1-4, the hydrogen bonds involving the amide groups play important role to stabilize the resultant frameworks. The photoluminescence properties of the DPBA-3 and the complexes were studied in the solid state at room temperature. 相似文献
12.
Salah S. Massoud Franz A. Mautner Febee R. Louka Sebastian Dechert 《Inorganica chimica acta》2011,370(1):435-443
The reaction of aqueous solutions of the preformed 1:1 Cu(ClO4)2-polydentate amine with tetrasodium 1,2,4,5-benzene tetracarboxylate (Na4bta) afforded three different types of polynuclear compounds. These include the tetranuclear complexes: [Cu4(Medpt)4(μ4-bta)(ClO4)2(H2O)2](ClO4)2·2H2O (1), [Cu4(pmdien)4(μ4-bta)(H2O)4](ClO4)4 (2), [Cu4(Mepea)4(μ4-bta)(H2O)2](ClO4)4(3), [Cu4(TPA)4(μ4-bta)](ClO4)4·10H2O (4) and [Cu4(tepa)4(μ4-bta)](ClO4)4·2H2O (5), the di-nuclear: [Cu2(DPA)2(μ2-bta)(H2O)2]·4H2O (6), [Cu2(dppa)2(μ2-bta)(H2O)2]·4H2O (7) and [Cu2(pmea)2(μ2-bta)]·14H2O (8) and the trinuclear complex [Cu3(dppa)3(μ3-bta)(H2O)2.25](ClO4)2·6.5H2O (9) where Medpt = 3,3′-diamino-N-methyldipropylamine, pmedien = N,N,N′,N″,N″-pentamethyldiethylenetriamine, Mepea = [2-(2-pyridyl)ethyl]-(2-pyridylmethyl)methylamine, TPA = tris(2-pyridylmethyl)amine, tepa = tris[2-(2-pyridyl)ethyl)]amine, DPA = di(2-pyridymethyl)amine, dppa = N-propanamide-bis(2-pyridylmethyl)amine and pmea = bis(2-pyridylmethyl)-[2-(2-pyridylethyl)]amine. The complexes were structurally characterized by elemental analyses, spectroscopic techniques, and by X-ray crystallography for complexes 1, 2, 4, 6, 7 and 9. X-ray structure of the complexes reveal that bta4− is acting as a bridging ligand via its four deprotonated caboxylate groups in 1, 2 and 4, three carboxylate groups in 9 and via two trans-carboxylates in 6 and 7. The complexes exhibit extended supramolecular networks with different dimensionality: 1-D in 2 and 4 due to hydrogen bonds of the type O-H···O, 2-D in 1 and 7, and 3-D network in 6 as a result of hydrogen bonds of the types N-H···O and O-H···O. Magnetic susceptibility measurements showed very weak antiferromagnetic coupling between the CuII ions in 1-5, 7-9 (|J| = 0.02-0.87 cm−1) and weak ferromagnetic coupling for 6 (J = 0.08 cm−1). 相似文献
13.
A linear tri-nuclear oxamato bridged copper(II) complex [Cu3(pba)(dpa)2(H2O)(ClO4)](ClO4)·H2O (1) (pbaH4 = 1,3-propanediylbis(oxamic acid), dpa = 2,2′-dipyridylamine) was isolated from the reaction mixture of Na2[Cu(pba)]·3H2O, copper perchlorate hexahydrate and dipyridylamine in methanol. On reaction with dpa or DMF in basic medium (KOH) at ambient temperature complex 1 changed to dinuclear oxalate bridged copper(II) derivatives, [Cu2(μ-C2O4)(dpa)4](ClO4)2 (2) and [Cu2(μ-C2O4)(dpa)2(DMF)2](ClO4)2 (3), respectively. The complexes 1, 2 and 3 have been characterized by physicochemical and spectroscopic tools, and also by the X-ray single crystal analysis. The hydrolysis of 1 in basic medium and thermo-gravimetric analysis has been studied. Absorption and emission spectral studies showed that complex 1 interacts with calf thymus-DNA (CT-DNA) with a binding constant (Kb) of 4.01 × 104 M−1 and linear Stern-Volmer quenching constant (Ksv) of 6.9 × 104. A strong anti-ferromagnetic interaction with a coupling constant JCuCu of 320.0 ± 0.3 cm−1 was observed from the study of magnetic behavior of complex 1 in the temperature range of 2-300 K. Electrochemical equivalency of three copper(II) ions in 1 was identified by getting only one quasi reversible cyclic voltammogram. 相似文献
14.
Tanmay K. Jana Rabindranath Pradhan Subhajit Dinda Corine Simonnet Inhar Imaz Léopold Fournès Francis Sécheresse Ramgopal Bhattacharyya 《Inorganica chimica acta》2009,362(10):3583-3594
Iron (II) and iron (III) complexes, [FeII(DEDTC)2(dppe)] · CH2Cl2 (1), [FeII(ETXANT)2(dppe)] (2) (DEDTC = diethyldithiocarbamate, ETXANT = ethyl xanthate, dppe = 1,2-bis (diphenylphosphino) ethane), and [FeIII(DEDTC)2(dppe)] [FeIIICl4] (3) have been synthesized and characterized. Since 3 contains two magnetic centers, an anion metathesis reaction has been conducted to replace the tetrahedral FeCl4− by a non-magnetic BPh4− ion producing [FeIII(DEDTC)2(dppe)]BPh4 (4) for the sake of unequivocal understanding of the magnetic behavior of the cation of 3. With the similar end in view, the well-known FeCl4− ion, the counter anion of 3, is trapped as PPh4[FeIIICl4] (5) and its magnetic property from 298 to 2 K has been studied. Besides the spectroscopic (IR, UV-Vis, NMR, EPR, Mass and XPS) characterization of the appropriate compounds, especially 2, others viz. 1, 3 and 4 have been structurally characterized by X-ray crystallography. While FeII complexes, 1 and 2, are diamagnetic, the FeIII systems, namely the cations of 3, and 4 behave as low-spin (S = 1/2) paramagnetic species from 298 to 50 K. Below 50 K 3 shows gradual increase of χMT up to 2 K suggesting ferromagnetic behavior while 4 exhibits gradual decrease of magnetic moment from 60 to 2 K, indicating the occurrence of weak antiferromagnetic interaction. These conclusions are supported by the Mössbauer studies of 3 and 4. The Mössbauer pattern of 1 exhibits a doublet site for diamagnetic (2-400 K) FeII. The compounds 1, 2 and 4 encompass interesting cyclic voltammetric responses involving FeII, FeIII and FeIV. 相似文献
15.
Luigi Busetto Fabio Marchetti Stefano Zacchini Valerio Zanotti 《Inorganica chimica acta》2005,358(5):1469-1484
The new diiron alkynyl methoxy carbene complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO){C(OMe)CCR′}(Cp)2]+ (R = 2,6-Me2C6H3 (Xyl), R′ = Tol, 3a; R = Xyl, R′ = Ph, 3b; R = Xyl, R′=Bun, 3c; R = Xyl, R′=SiMe3, 3d; R = Me, R′ = Tol, 3e; R = Me, R′ = Ph, 3f) are obtained in two steps by addition of R′CCLi (R′ = Tol, Ph, Bun, SiMe3) to the carbonyl aminocarbyne complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)2(Cp)2]+ (R = Xyl, 1a; Me, 1b), followed by methylation of the resulting alkynyl acyl compounds [Fe2{μ-CN(Me)(R)}(μ-CO)(CO){C(O)CCR′}(Cp)2] (R = Xyl, R′ = Tol, 2a; R = Xyl, R′ = Ph, 2b; R = Xyl, R′ = Bun, 2c; R = Xyl, R′ = SiMe3, 2d; R = Me, R′ = Tol, 2e; R = Me, R′ = Ph, 2f). Complexes 3 react with secondary amines (i.e., Me2NH, C5H10NH) to give the 4-amino-1-metalla-1,3-dienes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO){C(OMe)CHC(R′)(NMe2)}(Cp)2]+ (R = Xyl, R′ = Tol, 4a; R = Xyl, R′ = Ph, 4b; R = Me, R′ = Ph, 4c) and [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){C(OMe)CHC(Tol)(NC5H10)}(Cp)2]+, 5. The addition occurs stereo-selectively affording only the E-configured products. Analogously, addition of primary amines R′NH2 (R′ = Ph, Et, Pri) affords the 4-(NH-amino)-1-metalla-1,3-diene complexes [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){C(OMe)CHC(R)(NHR′)}(Cp)2]+ (R = Ph, 6a; Et, 6b; Pri, 6c). In the case of 6a, only the E isomer is formed, whereas a mixture of the E and Z isomers is present in the case of 6b,c, with prevalence of the latter. Moreover, the two isomeric forms exist under dynamic equilibrium conditions, as shown by VT NMR studies. Complexes 6 are deprotonated by strong bases (e.g., NaH) resulting in the formation of the neutral vinyl imine complexes [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){C(OMe)CHC(NR)(Tol)}(Cp)2] (R = Ph, 7a; Et, 7b; Pri, 7c); the reaction can be reverted by addition of strong acids. X-ray crystal structures have been determined for 3a[CF3SO3] · Et2O, 4c[CF3SO3], 6a[BF4] · CH2Cl2, 6c[CF3SO3] · 0.5Et2O and 7a · CH2Cl2. 相似文献
16.
The reaction of purine nucleobases (adenine, 3-methyladenine and 9-methylguanine) with a metallic salt in the presence of potassium oxalate yields three compounds with formulae {[Cd(μ-ox)(H2O)(Hade)]·H2O}n (1), {[Cu(μ-ox)(H2O)(3Meade)]·H2O}n (2) and [Cu(ox)(H2O)2(9Megua)]·2.5H2O (3). Crystal structures of compounds 1-2 consist of 1D zig-zag chains in which cis-[M(H2O)(nucleobase)]2+ fragments are linked by bis-bidentate oxalato ligands. In compound 1, the nucleobase is coordinated through the minor groove N3 atom, and the resulting non-canonical 7H-adenine tautomer is stabilized by non-covalent interactions involving more basic N9 and N7 sites. In compound 2, the mutagenic 3-methyladenine is attached to the metal atoms by means of the imidazole N7 atom. The dissimilar binding pattern of the nucleobases produces significant differences in the supramolecular architectures of compounds 1 and 2 which are essentially governed by an extensive network of non-covalent interactions such as hydrogen bonded adenine-adenine base pairs, hydration of the nucleobases, carboxylato-nucleobase associations, and face-to-face π-π stacking. The model 9-methylguanine nucleobase of compound 3 exhibits its usual coordination mode through the major groove N7 atom to form two monomeric [(Cu(ox)(H2O)2(9Megua)] units which are held together by means of Watson-Crick like hydrogen bonds between the guanine moieties and the inorganic frameworks generating almost planar tetrameric metal-organic aggregates. The 3D packing of the complex entities affords an open structure containing voids which are filled by decameric (H2O)10 clusters. Variable-temperature magnetic susceptibility measurements of compound 2 show the occurrence of antiferromagnetic intrachain interactions in good agreement with the structural features of its 1D metal-oxalato framework. 相似文献
17.
Mark Bartholomä 《Inorganica chimica acta》2010,363(8):1659-934
A series of bifunctional chelates of the type dipicolylamino-alkylcarboxylate (NC5H4CH2)2N(CH2)nCO2H (n = 1-4; HL1-HL4, respectively) has been prepared. Reactions of the ligands in aqueous methanol/N,N-dimethylformamide with the appropriate Cu(II) salts yielded the compounds [CuL1](NO3)·H2O (1·H2O), [CuL2(H2O)]BF4·H2O (2·H2O), [Cu(HL3)(SO4)]2 (3) and [CuL4(NO3)]·MeOH (4·MeOH). While compounds 1, 2 and 4 are one-dimensional, the detailed connectivities within the chains are quite distinct, depending on factors such as alkyl chain length and ligation of aqua ligands or anionic components. In contrast to 1, 2 and 4, the structure of 3 is molecular, a binuclear assembly of edge-sharing Cu(II) ‘4+2’ distorted octahedra. The Cd(II) species, [{CdL2}2(SO4)]·4H2O (5·4H2O), prepared from HL2 and CdSO4·nH2O in aqueous methanol/N,N-dimethylformamide, is two-dimensional, with a network constructed from binuclear units of seven coordinate Cd(II), , linked through bridging SO42− groups to produce an assembly of linked hexagonal rings [{CdL2}2(SO4)]6. 相似文献
18.
Khodayar Gholivand Hamid Reza Mahzouni Mehrdad Pourayoubi Shadi Amiri 《Inorganica chimica acta》2010,363(10):2318-4308
Monodentate and bidentate ligands PhNHP(O)(NC4H8O)2 (1) and PhC(O)NHP(O)(NH(tert-C4H9))2 (2) were used to prepare new 7, 9 and 10-coordinated lanthanum(III) complexes; La(1)2Cl3(H2O)2 (3), La(1)2(NO3)3H2O.La(1)2(NO3)3CH3CN (4) and La(2)2(NO3)3 (5), respectively. Crystallization of compound 2 in CH3OH:CH3CN leads to one conformer in contrast to the crystallization result from CHCl3:n-C7H16 (two conformers). Compound 4 contains two independent nine-coordinated La(III) complexes that are different in the solvated molecules (H2O and CH3CN). Some structural and electronic perturbations in coordinated ligand were occurred upon complexation, that are confirmed by increase of 2JPH, 3JPH and 6JPH coupling constants from the free ligand 1 to complexes 3 and 4. The steric repulsions in the first coordination sphere of La3+ ion, metal-ligand (M-L) binding strength and PO stretching frequency are very influenced by changing the counter ion from Cl− to . Comparing the X-ray crystallography data of free ligand 2 with bis-chelated complex 5, it is found that the phosphoryl group is more reactive than carbonyl counterpart. A blue shift of the ν(N-H) vibration is observed in line with the weakening of the hydrogen bond from N-H···OPhosphoryl in 1 to N-H···Cl in 3. Three dimensional butterfly-shape structures are seen in the unit cell of complex 3, which are produced by OWater-H···OMorpholine hydrogen bonds. 相似文献
19.
The reaction of the octahedral mononuclear complex, trans(N)-[Co(l-pen-N,O,S)2]− (pen = penicillaminate), with [PtCl2(bpy)] (bpy = 2,2′-bipyridine) stereoselectively gave an optically active S-bridged dinuclear complex, [Pt(bpy){Co(l-pen)2}]Cl · 3H2O (2Cl · 3H2O), whose structure is enantiomeric to the previously reported [Pt(bpy){Co(d-pen)2}]Cl · 3H2O (1Cl · 3H2O). The mixture of equimolar amounts of 1Cl · 3H2O and 2Cl · 3H2O in H2O crystallizes as [Pt(bpy){Co(d-pen)2}]0.5[Pt(bpy){Co(l-pen)2}]0.5Cl · 7H2O (3Cl · 7H2O), in which the enantiomeric complex cations 1 and 2 are included in the ratio of 1:1. The crystal structures of 2Cl · 3H2O and 3Cl · 7H2O were determined by X-ray crystallography, and compared with that of 1Cl · 3H2O. The structural feature for 2 is essentially consistent with that for 1, except for the absolute configurations around the octahedral Co(III) center. The optically active complex cation 2 exists as a monomer, accompanied by no intermolecular interactions in the π-electronic systems of bpy moieties. In the crystals of 3Cl · 7H2O, on the other hand, the enantiomeric complex cations, [Pt(bpy){Co(d-pen)2}]+ and [Pt(bpy){Co(l-pen)2}]+, are arranged alternately while overlapping the bpy planes along a axis, and the π electronic system of the bpy framework in [Pt(bpy){Co(d-pen)2}]+ interacts with those in [Pt(bpy){Co(l-pen)2}]+. Differences between the crystal structures of 2Cl · 3H2O and3Cl · 7H2O significantly reflect their diffuse reflectance spectra. In aqueous solution, each cation in both 2Cl · 3H2O and 3Cl · 7H2O is comparatively put on a free environment without such intermolecular interactions. 相似文献
20.
《Inorganica chimica acta》2004,357(12):3574-3582
The copper(II) complexes [Cu(PyTT)2(H2O)](NO3)2 (A) and [CuCl2(μ-PyTT)2CuCl(H2O)]Cl · 3H2O (B) were synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy, UV-Vis-NIR diffuse reflectance and magnetic susceptibility measurements. In the mononuclear compound A the copper ion is in a distorted square pyramidal geometry, with the equatorial plane formed by two thiazoline nitrogen atoms, one imino nitrogen atom and one water molecule, whereas the axial site is occupied by one imino nitrogen atom. The compound B is dinuclear and both Cu(II) centres present environments that can be described as slightly distorted square pyramidal geometries. The observed molar magnetic susceptibility for A (μ=2.13 BM) allows to exclude metal-metal interactions, supporting a monomeric structural formulation for this compound. In compound B, magnetic susceptibility measurements in the temperature range 6.2-288 K show an intradimer antiferromagnetic interaction (J=−11.8 cm−1). 相似文献