共查询到20条相似文献,搜索用时 12 毫秒
1.
Wen‐Juan Shi 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(8):m284-m286
In the title salt, catena‐poly[[[aquacopper(II)]‐μ‐3‐(2‐pyridylmethyleneamino)propanoato‐κ4N,N′,O:O′] perchlorate], {[Cu(C9H9N2O2)(H2O)]ClO4}n, the monomeric unit contains a square‐based pyramidal CuII centre. The four basal positions are occupied by a tridentate anionic Schiff base ligand which furnishes an NNO‐donor set, with the fourth basal position being occupied by an O‐donor atom from the carboxylate group of an adjacent Schiff base ligand. The coordination sphere is completed by a water molecule at the apical position. Interestingly, each carboxylate group in the ligand forms a syn–anti‐configured bridge between two CuII centres, leading to left‐handed chiral helicity. The framework also exhibits O—H...O hydrogen bonds involving the water molecules and an O atom of the perchlorate anion. 相似文献
2.
František Březina Zdeněk Smékal Zdeněk Šindelář Richard Pastorek Jerzy Mroziňski 《Transition Metal Chemistry》1996,21(3):287-288
Summary A tetradentate Schiff base derived from diacetyl monoxime and m-phenylenediamine (H2mphdao2) reacts in MeOH with NiI2 to form the trinuclear complex Ni3(mphdao2)2I2, which was characterized by elemental and thermal analyses, and i.r. and u.v.-vis. spectroscopies. The magnetic properties have been investigated in the 4.2–300 K range. 相似文献
3.
Salassa G Castilla AM Kleij AW 《Dalton transactions (Cambridge, England : 2003)》2011,40(19):5236-5243
A metal template approach affords in high yield a tetra-Zn(salphen) macrocycle (3) which shows strong and cooperative self-assembly mediated by the formation of Zn(salphen) dimer units held together via μ(2)-phenoxo interactions. A cooperative binding mode for the tetranuclear Zn(4) macrocycle 3 is supported by comparison of UV-vis and fluorescence titration data recorded for 3 when compared with respective mononuclear and dinuclear Zn(salphen) model compounds. UV-vis dilution experiments carried out for Zn(4) macrocycle 3 and its Pd(4) analogue 4, as well as comparative TEM studies involving the same tetranuclear macrocycles further support the strong assembly behavior of 3. This self-assembly seems to be primarily dictated by its ability to form multiple, self-assembled dimeric [Zn(salphen)](2) units. 相似文献
4.
Uranyl Schiff base complex [(UO(2))(2)(Salpro)(OH)(Solvent)(2)] (1) in the presence of excess of ethylenediamine (EDA) does not undergo nucleophilic addition (hydrolysis) and substitution (transamination) reactions due to an extended chelation [2N, 3O + OH] by the flexible backbone. 相似文献
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Sandeepta Saha Guillaume Pilet Antonio Frontera 《Journal of Coordination Chemistry》2017,70(8):1389-1405
One ONNO-donor tetradentate Schiff base ligand LH2 was derived from the condensation of salicylaldehyde and 1,3-diaminopropane and reacted with Cu(NO3)2·6H2O and NaNCO to yield one trinuclear complex with molecular formula [Cu3L2(µ1,1-NCO)2]. The synthesized complex was characterized by IR, UV–vis spectroscopy, and electrochemical analysis. Single-crystal X-ray diffraction study explores that the two terminal copper atoms adopt square pyramidal geometry, whereas the central copper atom situated at the inversion center is surrounded by four phenoxo oxygens and two end-on cyanato anions to adopt an octahedral geometry. The ONNO-tetradentate Schiff base ligand coordinates with the copper(II) ion via two oxygen atoms of the phenoxo-group and two nitrogen atoms from the imine moiety. A theoretical density functional theory (DFT) calculation was also carried out to supplement the experimental results. All the DFT calculations were done in gas phase. 相似文献
7.
Ying He 《Journal of organometallic chemistry》2011,696(13):2689-6358
Heterogeneous Sonogashira coupling of terminal alkynes with aryl halides was studied over a polymer-supported macrocyclic Schiff base palladium complex. The cross-coupling reaction proceeded smoothly by adding a piperidine in water medium. The catalyst exhibited effective catalytic activities to afford the corresponding products in good to excellent yields under copper-free conditions. Furthermore, the catalyst could be easily recovered and reused for several times without a significant loss of its activity. 相似文献
8.
Aurkie Ray Dipali Sadhukhan Georgina M. Rosair Carlos J. Gmez-García Samiran Mitra 《Polyhedron》2009,28(16):3542-3550
A new tetradentate N2O2 donor Schiff base ligand [OHC6H4CHNCH2CH2CH(CH2CH3)NCHC6H4OH = H2L ] was obtained by 1:2 condensation of 1,3-diaminopentane with salicylaldehyde and has been used to synthesise an unusual copper(II) complex whose asymmetric unit presents two structurally different almost linear trinuclear units [Cu3(μ-L)2(ClO4)2] [Cu3(μ-L)2(H2O)(ClO4)2] (1). The ligand and the complex were characterised by elemental analysis, FT-IR, 1H NMR and UV–Vis spectroscopy in addition electrochemical and single crystal X-ray diffraction studies were performed for the complex. The magnetic properties of 1 reveal the presence of strong intra-trimer (J1 = −202(3) cm−1 and J2 = −233(3) cm−1) as well as very weak inter-trimer (zJ′ = −0.11(1) cm−1) antiferromagnetic interactions. 相似文献
9.
Yang X Jones RA Lynch V Oye MM Holmes AL 《Dalton transactions (Cambridge, England : 2003)》2005,(5):849-851
Near infrared luminescence is observed in tetrametallic [Zn2Yb2L2(mu-OH)2Cl4].2MeCN which is obtained from the Zn3 Schiff-base complex [Zn3L2(NO3)2].MeOH, (H2L =N,N'-bis(5-bromo-3-methoxysalicylidene)propylene-1,3-diamine). 相似文献
10.
Balram P. Baranwal Talat Fatma Rinkoo D. Gupta Tarkeshwar Gupta 《Transition Metal Chemistry》2007,32(4):501-506
Oxo-centered, trinuclear, mixed-ligand complexes of chromium(III) have been synthesized by stepwise substitutions of acetate
ions of [Cr3O(OOCMe)4(OOCR)3] · 3MeOH (1) and the isolated products of the type [Cr3O(OOCMe)2 (SB)(OOCR)3]PF6 · 3MeOH (2), [Cr3O(OOCMe)(SB)2(OOCR)3]PF6 · 3MeOH (3) and [Cr3O(SB)3(OOCR)3]PF6 · 3MeOH (4) [where R = C13H27 and HSB = C6H4(OH)CHNC6H4Cl] have been characterized by a full battery of complementary physico–chemical methods including spectral (infrared, electronic,
FAB mass and powder XRD) studies, elemental and thermogravimetric analyses, molar conductance and magnetic susceptibility
measurements. The infrared spectra suggest the bridging nature of both carboxylate and Schiff base anions along with ν
asym(Cr3O) vibrations in the complexes. The trinuclear nature of the complexes has been assessed from FAB mass data. Electronic spectra
and magnetic moment values were consistent with chromium(III) ion present in an octahedral environment which was supported
by their powder X-ray diffraction data. Cyclic voltammetric data of complex (4) indicate a reversible oxidation wave and an irreversible reduction wave in the range − 1.2–0.6 V. The decomposition pathway
of all the complexes has been discussed on the basis of thermogravimetric analysis data. Conductance data indicate the monocationic
nature of the complexes and their plausible structure has been established on the basis of above physico–chemical studies. 相似文献
11.
The crystal structure of a new heterodinuclear lanthanide complex, L2Cu(Me2CO)Dy(NO3)3 (L2=N,N′-bis(2-hydroxy-3-methoxy-benzylidene)-ethylenediamine) has determined and the magnetic properties of the complex investigated. (C18H18N2O4)Cu(C3H6O)Dy(NO3)3, monoclinic, space group P21/c, with a=9.875(2), b=18.870(7), c=15.675(8) Å, β=95.45(3)°, V=2908(2) Å3, Z=4. The structure consists of ordered dinuclear units with CuII and DyIII ions bridged by two phenolato oxygen atoms of the Schiff base ligand. The CuII ion has a square-pyramidal geometry involving the basal N2O2 donor atoms of the Schiff base ligands and one oxygen atom of the acetone molecule at the apex position. The DyIII ion is decacoordinated by the four oxygen atoms of L2 and six oxygen atoms from the three bidentate nitrate ions. The Cu?Dy separation is 3.461(2) Å. The χT versus T plots, χ being the molar magnetic susceptibility per CuIIDyIII unit and T the temperature, has been measured in the 4.5-300 K temperature range. The magnetic properties of the compound are dominated by the crystal field effect on the DyIII site, masking the magnetic interaction between the paramagnetic centers. 相似文献
12.
Néstor Novoa Vincent Dorcet Sourisak Sinbandhit Carolina Manzur 《Journal of Coordination Chemistry》2014,67(23-24):4101-4113
The tridentate ONO-donor Schiff base ligand derived from the condensation of 1-ferrocenyl-1,3-butanedione and 2-aminophenol, generated in situ and treated further with potassium tert-butoxide, reacted in THF with Co(NO3)2·6H2O in the presence of pyridine to afford the ionic complex [{(η5-C5H5)Fe(η5-C5H4)-C(O)CH=C(CH3)N-C6H4-2-O}2Co(III)]-[K(HOCH2CH3)2]+ (1, 50% yield). Compound 1 was characterized by elemental analysis, FT-IR, and multidimensional 1H and 13C NMR spectroscopy. Single-crystal X-ray diffraction reveals that the two metalloligands are meridionally coordinated to a Co(III) ion that adopts a slightly distorted octahedral geometry. The doubly solvated potassium counter-ion is asymmetrically positioned with respect to the two metalloligands. Such an arrangement allows the observation by 1H NMR of restricted rotation of the ferrocenyl units and the splitting of both carbonyl and imine carbons, thus suggesting that the structure observed in the solid state is retained in solution. Complex 1 exhibits in its cyclic voltammetry curve two anodic reversible waves attributed to the oxidation of Co(III)-phenolates into Co(III)-phenoxyl radical and that of the ferrocenyl fragment into its ferrocenium counterpart. 相似文献
13.
Research on Chemical Intermediates - In the present studies, a Schiff base ligand and complex were synthesized by condensation reaction of 2-hydroxy-1-napthaldehyde and 4-methyl-1,3-phenyldiamine.... 相似文献
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16.
The title compound [In(C22H30N4O4)]Cl (I) bis[(N-salicylidene-N′-(2-hydroxyethyl)ethyleneediamine) indium(III) chloride is prepared, and its crystal structure
is determined by single crystal X-ray diffraction at room temperature. The complex crystallizes in the monoclinic space group
P21/n, a = 9.9704(6) ?, b = 24.9554(15) ?, c = 10.5707(6) ?, β = 116.46(2)°, V = 2354.6(2), Z = 4. The X-ray analysis reveals that the InIII ion is surrounded by four nitrogen and two oxygen atoms from two ligands leading to a distorted octahedral geometry. The
molecule has the form of tongs at a junction point with the metal. Five membered rings adopt envelope conformation. In the
crystal structure, the molecules are linked via N-H...Cl, O-H...O, O-H...Cl, and C-H...Cl intermolecular interactions. The
structure is further stabilized by C-H...π (arene) interactions. 相似文献
17.
Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity (ca. 95%) and high molecular weight (ca, 10^5) in the presence of the triisobutyl aluminium (AliBu3) as cocatalyst, The microstructure of obtained polyisoprene was investigated by FTIR, 1^H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method. 相似文献
18.
《Solid State Sciences》2007,9(3-4):267-273
Gadolinium(III) tripodal Schiff base (tris(((5-chlorosalicylidene)amino)ethyl)amine) complex has been obtained and investigated by infrared spectroscopy (IR), magnetic susceptibility, and electron paramagnetic resonance (EPR) methods. Comparison of IR bands in ligand and gadolinium complex confirmed the formation of the gadolinium complex and allowed to propose its structure. Both electron ionization and electron spray molecular spectroscopy spectra confirmed the [1:1] proportion of a ligand to metal in gadolinium tripodal Schiff base complex sample. IR spectroscopy and TG–DTA excluded the presence of water molecule in the metal coordination sphere. X-ray powder analysis applying Fullprof computer program has shown that the investigated sample was monophase with the monoclinic symmetry of the unit cell having the lattice constants: a = 10.028(4) Å, b = 13.282(5) Å, c = 21.20(1) Å and β = 101.58(4)°. Space group P21/c, Z = 4. EPR spectra of the complex have been registered in the 4–300 K temperature range. Each spectrum has been fitted using EPR–NMR computer program and the values of the spin-Hamiltonian parameters at each temperature have been calculated. Temperature dependence of the integrated intensity of the EPR spectrum allowed revealing the magnetic interactions in the spin system of this compound. Comparison of the temperature dependence of dc magnetic susceptibility (χ) and EPR susceptibility (χEPR) showed significant differences between these quantities due to the presence of short-lived clusters with a non-magnetic ground state. 相似文献
19.
Liangliang Zhang Fuling Liu Shuai Yuan Xiaoyang Wang Di Sun 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(4):m97-m99
A novel one‐dimensional CuII coordination polymer, catena‐poly[bis(μ4‐3‐{[2‐(3‐hydroxy‐2‐oxidobenzylidene)hydrazinylidene]methyl}benzene‐1,2‐diolato)dimethanoltricopper(II)], [Cu3(C14H10N2O4)2(CH3OH)2]n, (I), was constructed with a di‐Schiff base supported centrosymmetric trinuclear CuII subunit. In the subunit, two peripheral symmetry‐related CuII cations have square‐pyramidal CuNO4 geometry and the central third CuII cation lies on an inversion centre with octahedral CuN2O4 geometry. In (I), each partially deprotonated di‐Schiff base 3‐{[2‐(3‐hydroxy‐2‐oxidobenzylidene)hydrazinylidene]methyl}benzene‐1,2‐diolate ligand (Hbcaz3−) acts as a heptadentate ligand to bind the CuII centres into chains along the a axis. A centrosymmetric Cu2O2 unit containing an asymmetrically bridging O atom, being axial at one Cu atom and equatorial at the other Cu atom, links the trinuclear CuII subunit into a one‐dimensional chain, which is reinforced by intramolecular phenol–methanol O—H...O and methanol–phenolate O—H...O hydrogen bonds. Interchain π–π stacking interactions between pyrocatechol units, with a distance of 3.5251 (18) Å, contribute to the stability of the crystal packing. 相似文献
20.
《Tetrahedron: Asymmetry》2007,18(23):2820-2827
A series of trimeric variants of the efficient and well known Bolm’s chiral vanadium salen catalysts are reported. These C3-symmetric trinuclear chiral Schiff bases were synthesized by condensing a variety of trialdehydes with optically active aminoalcohols. The catalytic activity of the chiral vanadium complexes of these ligands was investigated for the enantioselective oxidation of prochiral sulfides using hydrogen peroxide as an oxidant. The procedure afforded the corresponding sulfoxide in good yield and the enantioselectivities were comparable to those obtained with the mononuclear complexes. 相似文献