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1.
Three new heteroleptic Cu(I) complexes containing one phenanthroline and one diphosphine type ligand ([Cu(N-N)(P-P)]+) have been prepared. In particular, one ligand is constituted by 1,10-phenanthroline (1), 2,9-dimethyl-1,10-phenanthroline (2) and 2,9-diphenethyl-1,10-phenanthroline (3) and the other ligand is in all cases 1,1′-bis(diphenylphosphino)ferrocene (dppf). Therefore, copper and iron metal centres are quite close one another, as evidenced by X-ray crystal diffraction. The structure together with the electrochemical and photophysical properties of these complexes have been compared to that of the corresponding complexes where dppf has been replaced by bis[2-(diphenylphosphino)-phenyl]ether (POP). Cyclic voltammetric experiments evidenced that the first oxidation process is located on the ferrocene moiety and that oxidation of Cu(I) is moved to more positive potential values and a chemical reaction is coupled to the electron transfer process. The absorption spectra show a metal-to-ligand charge transfer (MLCT) band, typical of Cu(I) phenanthroline complexes, at a higher energy compared to the homoleptic [Cu(N-N)2]+ species. No emission at either room temperature or 77 K has been observed for compounds 2 and 3, contrary to the high luminescence observed for the corresponding POP complexes. This result is consistent with a photoinduced energy transfer from the Cu(I) complex to the ferrocene moiety.  相似文献   

2.
The reaction of uranyl acetate with (2,2′-(1E,1′E)-(2-benzyl-3-hydroxyquinoxaline-6,7-diyl)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene) diphenol) (H2L1) at room temperature in methanol and chloroform yields the UO2L1 complex. Crystals were grown through solvent diffusion of the ligand-metal complex in dimethyl formamide with diethyl ether to prepare: UO2L1 · DMF (1). Complexes with 2,2′-(1E,1′E)-(2-benzyl-3-hydroxyquinoxaline-6,7-diyl)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)dibenzene-1,4-diol (H2L2) and 2,2′-(1E,1′E)-(2-hydroxy-3-isopropylquinoxaline-6,7-diyl)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)diphenol (H2L3) were also prepared, and crystals of the uranyl complexes (UO2L2 · DMF (2) and (3)) grown from DMF/ether. A fourth complex UO2L4 · H2O (4) was prepared through layering a solution of the tetra-tert-butyl substituted 2-quinoxalinol salen ligand H2L4 in acetone with an aqueous solution containing uranyl acetate. The complexes exhibit a symmetric core featuring a slightly distorted bicapped pentagonal geometry around the uranium center with two oxo-groups and two imine groups from the ligand chelating the ligand and the fifth site in the coordination plane of the ligand occupied by a solvent molecule. These compounds have been characterized using solution (NMR and UV-Vis) and solid-state (IR, X-ray crystallography) techniques. Complexes of H2L4 with early transition metals; Mn2+, Co2+, Ni2+, and Cu2+ are also prepared and characterized for comparison of solution and spectroscopic characteristics.  相似文献   

3.
Single crystal X-ray structural characterizations are recorded for a wide range of adducts of the form MX:dppx (1:1)(n), M = silver(I) (predominantly), copper(I), X = simple (pseudo-) halide or oxy-anion (the latter spanning, where accessible, perchlorate, nitrate, carboxylate - a range of increasing basicity), dppx=bis(diphenylphosphino)alkane, Ph2P(CH2)xPPh2, x = 3-6. Adducts are defined of two binuclear forms: (i) [LM(μ-X)2L], with each ligand chelating a single metal atom, and (ii) [M(μ-X)2(μ-(P-L-P′))2M′] where both ligands L and halides bridge the two metal atoms; a few adducts are defined as polymers, the ligands connecting M(μ-X)2M′ kernels, this motif persisting in all forms. Synthetic procedures for all adducts have been reported. All compounds have been characterized both in solution (1H, 13C, 31P NMR, ESI MS) and in the solid state (IR).  相似文献   

4.
One-pot reaction of cobalt(II) nitrate hexahydrate Co(NO3)2 · 6H2O with H2salpn (N,N′-bis(salicylidene)-1,3-diaminopropane) in presence of a large excess of sodium azide (NaN3) gives the new Co(III) compound {Na[CoIII(μ-salpn)(μ1,1-N3)2]}n (1), which was characterized by single crystal X-ray diffraction analysis. The crystal structure shows polymeric 1D complex generated by the hexadentate Schiff base salpn2− and two crystallographically different azide ligands. The two nitrogen atoms of the salpn ligand are bonded to the cobalt(III) ion while each phenoxo oxygen atom is bonded to the same Co(III) ion and to two equivalent sodium ions. Each azide ligand acts with the end-on bridging coordination mode between Co(III) and Na(I) ions. The Co(III) ion adopts a distorted octahedral geometry arising from two oxygen and two nitrogen atoms of the salpn ligand and from two nitrogen atoms of the two crystallographically different azide ligands in trans positions. Such [Co(salpn)(N3)2] entities are connected each other by sodium ions through four oxygen atoms of two equivalent Schiff base ligands and two nitrogen atom of the two different azide ligands to generate the 1D structure of 1.  相似文献   

5.
The preparation of 1,1′-bis(β-hydroxyethyl)ferrocene (1) by oxidation of 1,1′-divinylferrocene is described. Compound 1 has been characterized by 1H and 13C{1H} NMR, and cyclic voltammetry. The electrochemical data are compared to ferrocene and the closely related 2-ferrocenylethanol, 2.  相似文献   

6.
The complexes Au2Cl2(P-P) with P-P=biphep (2,2-bis(diphenylphosphino)-1,1-biphenyl), binap (2,2-bis(diphenylphosphino)-1,1-binaphthyl) and xantphos (9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene), were prepared and characterized by elemental analysis and ESI-MS. The solid compounds show a r.t. phosphorescence. While the binap complex emits from an intraligand (IL) triplet, the luminescence of the biphep complex originates from a metal-centered (MC) triplet which is presumably lowered by gold-gold interaction. The xantphos complex displays a dual phosphorescence. In this case, the emitting triplets are of the IL and MC type.  相似文献   

7.
Benzoylhydrazones and semicarbazones derived from 2,6-diacetylpyridine react with common dioxouranium(VI) compounds such as uranyl nitrate or [NBu4]2[UO2Cl4] to form air-stable complexes. 2,6-Diacetylpyridinebis(benzoylhydrazone) (H2L1), 2,6-diacetylpyridinebis(N4-phenylsemicarbazone) (H2L2) and the asymmetric proligand 2,6-diacetylpyridine(benzoylhydrazone)(N4-phenylsemicarbazone) (H2L3) give yellow products of the composition [UO2(L)]. The neutral compounds contain doubly deprotonated ligands and possess uranium atoms with distorted pentagonal-bipyramidal coordination spheres. The equatorial coordination spheres of the metal atoms can be extended by the addition of a monodentate ligand such as pyridine or DMSO. The uranium atoms in the resulting complexes have hexagonal-bipyramidal coordination environments with the oxo ligands in axial positions.X-ray diffraction studies on [UO2(L1)(DMSO)], [UO2(L2)], [UO2(L2)(DMSO)] and [UO2(L3)] show relatively short U-O bonds to the benzoylic oxygen atoms between 2.273(6) and 2.368(5) Å. This suggests a preference of these donor sites of the ligands over their imino and amine functionalities (U-N bond lengths: 2.502(7)-2.671(7) Å). The addition of a sixth ligand to the equatorial coordination sphere results in a lengthening of the metal-pyridine bonds.  相似文献   

8.
《Inorganica chimica acta》1988,150(2):279-285
Three new silver—tin complex salts with cis-1,2-bis(diphenylphosphino)ethylene have been synthesized. IR,31P and 119Sn NMR and conductivity data are reported and discussed together with the X-ray crystal structure of one of them, [Ag(cdppet)2][SnPh3(NO)3)2]. The silver atom is distorted tetrahedrally surrounded by the four phosphorus atoms of the two cdppet ligands. The tin atom is in a slightly distorted trigonal bipyramidal geometry with the phenyl carbon atoms in the equatorial plane and two oxygen atoms from monodentate nitrate groups at the apices.  相似文献   

9.
Solid complexes of lanthanide picrates with a new podand-type ligand, 2,2′-[(1,2-phenylene)bis(oxy)]bis(N-benzylacetamide) (L) have been prepared and characterized by elemental analysis, conductivity measurements, IR, electronic and 1H NMR spectroscopies. The crystal and molecular structures of the complex NdL(Pic)3 have been determined by single-crystal X-ray diffraction. The crystal structure shows that the Nd(III) ion is coordinated with four oxygen atoms of the ligand L and six oxygen atoms of three bidentate picrates. Furthermore, the NdL(Pic)3 complex units are linked by the intermolecular hydrogen bonds to form a three-dimensional (3-D) netlike supermolecule. Under excitation, Eu complex exhibited characteristic emissions. The lowest triplet state energy level of the ligand indicates that the triplet state energy level of the ligand matches better to the resonance level of Eu(III) than Tb(III) ion.  相似文献   

10.
The radical-scavenging capacities of ferrocenyl group and phenolic hydroxyl group in ferrocenyl chalcone were identified in this work. 1,1′-Diacetylferrocene was applied to condense with benzaldehyde, vanillin, and protocatechualdehyde to produce ferrocenyl chalcones, which were employed to interact with 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS+), 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. It was found that ferrocenyl chalcones as well as diacetylferrocene can trap these radicals effectively, and thus, concluded that both iron atom in ferrocene and phenolic hydroxyl group played the radical-scavenging role, and the radical-scavenging capacity of iron atom in ferrocene was even higher than that of phenolic hydroxyl group.  相似文献   

11.
The formation of uranium complexes of novel ligands belonging to phosphorylated 2-oxo-1,2-azaphospholane series, namely 2-ethoxy-1-diethoxyphosphoryl-2-oxo-1,2λ5-azaphospholane (1a) and both individual R,R- and R,S-diastereomers of the related 2-oxo-2-phenyl-1,2λ5-azaphospholanes 1b,c with different surrounding at the exocyclic phosphorus atom, has been studied. The structures of the complexes of ML composition obtained in the reaction with uranyl nitrate in 1:1 ratio were found to depend on the difference in donor properties of the oxygen atom of endo- and exocyclic phosphoryl groups. The ligand 1a possessing the greater difference, serves as O-monodentate one with metal-oxygen bonding via the endocyclic PO function while both isomers of 1b,c coordinate to uranyl cation in a O,O-bidentate fashion. In solutions the ML complexes reacted with air oxygen to afford (μ2-peroxo)-bridged uranium complexes [{UO2(L)NO3}22-O2)] which structures were confirmed by X-ray crystallography data.  相似文献   

12.
The phenol-based compartmental ligand Hpy2ald contains a tridentate amino arm and a weak donor aldehyde group at the 2 and at the 6 positions of the phenol ring, respectively. This ligand reacts with cobalt(II) perchlorate, cobalt(II) tetrafluoroborate and manganese(II) perchlorate, yielding dinuclear complexes, where two metal ions are doubly bridged by two deprotonated cresolate moieties. The coordination environment around the metal ions is then completed to a very distorted octahedron by three nitrogen donor atoms from the pendant amino arm and the oxygen atom of the aldehyde group. The crystal structures of the complexes, their spectroscopic and magnetic properties are reported.  相似文献   

13.
Copper(II) complexes of a new bis benzimidazole diamide ligand N-picolyl-N,N′-bis(2-methylbenzimidazolyl)hexanediamide [Pic-GBHA = L2] have been synthesized and characterized. One of the compound [Cu(L2)(NO3)2] has been structurally characterized. The copper atom is bound to two benzimidazolyl nitrogen atoms, two amide carbonyl oxygen atoms and a bidentate nitrate ion, resulting in a distorted octahedral geometry. EPR spectra obtained at low temperature indicate a tetragonal geometry in the solution state. Complexes display a quasi-reversible redox wave due to the Cu(II)/Cu(I) reduction process having fairly cathodic E1/2. These Cu(II) complexes were utilized to carry out oxidation of ditertbutylcatechol (DTBC) in methanol using molecular oxygen as the oxidant in. Low temperature EPR study of the oxidation reaction implicates the formation of an active copper species with fairly low A value. The presence of picolyl groups on the ligand also serve as a proton sponge giving 2-3 times higher rates of reaction in comparison to the non-picolylated ligand, implying a role of free basic groups in the pH control of enzymatic oxidation of catechols by catechol oxidase and tyrosinase.  相似文献   

14.
The reaction of triethylenetetramine, salicylaldehyde and benzaldehyde in 1:2:1 mole ratio in methanol at room temperature affords a novel μ-bis(tridentate) ligand H2L′ through the formation of an imidazolidine ring within the parent hexadentate precursor in a two step reaction. The ligand H2L′ reacts with Fe(ClO4)2 · 6H2O in aqueous methanol in the presence of triethylamine to form the mononuclear [FeIIIL](ClO4) complex, (where L2− is the anion of the parent hexadentate H2saltrien ligand) after the cleavage of the imidazolidine ring. The mononuclear complex has a structure with an N4O2 donor atom set of the hexadentate ligand forming a distorted octahedral coordination geometry around the metal atom as established from a crystal structure determination. The Fe-N(imine) distances are 1.934(10) and 1.948(9) Å, Fe-N(amine) distances are 2.062(8) and 2.076(9) Å and Fe-O(phenol) distances are 1.864(8) and 1.872(7) Å. The terminal oxygen donor atoms occupy cis positions and the remaining four nitrogen atoms (two cis amine and two trans imine) complete the coordination sphere. The mononuclear complex has a magnetic moment 1.89 μB corresponding to the low-spin 3d5 configuration. The UV-Vis spectrum of the end product, after the imidazolidine ring hydrolysis, is different from the spectrum of the initial reaction mixture containing the μ-bis(tridentate) ligand H2L′.  相似文献   

15.
《Inorganica chimica acta》1988,144(2):177-184
Various Cr, Mo and W carbonyl complexes of a tridentate ligand containing N and P as donor atoms, bis(2-(diphenylphosphino)ethyl)benzylamine (DPBA), have been synthesized. Reaction of M(CO)6 (M = Cr, Mo and W) with DPBA in a 1:1 mole ratio in toluene or xylene, resulted in the formation of facial and meridional complexes of the type [M(CO)3(DPBA)] (M = Cr, Mo and W). Interaction of Cr(CO)6 or Mo(CO)6 with DPBA and PPh3 in toluene yielded complexes of the composition [Cr(CO)3(DPBA)(PPh3)] and [Mo(CO)2(DPBA)(PPh3)], respectively. However reaction of W(CO)6 with DPBA and PPh3 yielded only [W(CO)3(DPBA)]. Reaction of Cr(CO)6 with DPBA and 1,2-bis(diphenylphosphino)ethane(diphos) in toluene for 24 h resulted in the formation of a mixed ligand complex, [Cr(CO)4(DPBA)(diphos)] where both the ligands coordinate to the metal atom through only one of their donor atoms. A unique binuclear complex of the composition [Mo(CO)2(DPBA)(diphos)]2 resulted, with the tridentate ligand DPBA acting as a bidentate bridging ligand, by the reaction of Mo(CO)6 with DPBA and diphos in refluxing xylene for 24 h. All the complexes are characterized by elemental analysis and infrared spectra. The 31P{1H} and 1H NMR spectral data of the complexes gave valuable information in elucidating the structures of the complexes. The ligand DPBA has found to behave in a triligate monometallic, biligate monometallic, monoligate monometallic and biligate bimetallic manner.  相似文献   

16.
Two dinuclear cobalt/copper compounds have been isolated from the reaction between N,N′-ethylenebis(salicylideniminato)cobalt(II), [Co(salen)], and copper(II) chloride in different conditions. The first one is a dinuclear cobalt(III)/copper(II) derivative, [Co(salen)Cl2Cu(EtOH)2Cl], 1, that have the cobalt atom six-coordinated to the four donor atoms of the salen ligand and to two chlorine atoms in a slightly distorted octahedral environment and the copper atom five-coordinated to the two bridging oxygen atoms of the salen ligand, two ethanol molecules and one extra chlorine atom. This compound is the only reported example of a cobalt/copper derivative with the cobalt maintaining the salen coordinative site, since the usual reaction takes place by a transmetalation process. This reaction is observed in the second derivative, [Cu(salen)CoCl2], 2, where the copper atom displaces the cobalt from the salen cavity. The copper atom adopts a square-planar coordinative environment, while the cobalt is tetrahedrically coordinated to the two bridging oxygen and two chlorine atoms. Both compounds present several intermolecular contacts that increase the dimensionality in the crystal and some of which can transmit magnetic interactions. The magnetic properties confirm the structural picture, with isolated copper(II) centres in 1, where the cobalt(III) is in the low spin form, and with antiferromagnetically coupled S = 1/2 and S = 3/2 centres in 2.  相似文献   

17.
Lead(II) complexes of S-methyldithiocarbazate (SMDTC), [Pb(SMDTC)(NO3)2] (1) and S-benzyldithiocarbazate (SBDTC), [Pb(SBDTC)(NO3)2] (2) have been synthesized for the first time and characterized by elemental analysis, IR and TGA techniques. The complexes were obtained by addition of the appropriate ligand to an aqueous ethanolic solution of lead(II) nitrate in 1:1 molar ratio. The X-ray crystal structure of complex 1 has been determined by single crystal X-ray diffractometry. In complex 1, lead(II) is in a nine coordinated sphere with seven oxygen atoms of the nitrate groups and thione sulfur, β-nitrogen of neutral bidentate NS chelating ligand. Three nitrate groups act as bidentate chelating whereas the fourth nitrate group is coordinating to the central lead(II) and at the same time it bridges with neighboring lead(II) atom. Coordination geometry of the central lead(II) atom has a tricapped trigonal prismatic arrangement with streochemically inactive lone pair. The lead atoms are linked into polymeric chains and these chains form twin polymeric ribbons linked through bridging oxygen atoms. The N-H?O hydrogen bond network between NSMDTC and Onitrate atom leads to self-assembled molecular conformation and stabilizes the crystal structure. The complex 2 with similar spectral and thermal behavior is expected to have a tricapped trigonal prismatic structure. The thermal behavior studies shows that the complexes start to decompose at relatively low temperature (ca. 110 °C) to give PbS residue.  相似文献   

18.
A series of [Cu(I)(2,2′-biquinoline)(L)](ClO4) complexes (L = bis(diphenylphosphino)methane (bppm), 1,2-bis(diphenylphosphino)ethane (bppe), 1,4-bis(diphenylphosphino)butane (bppb)) have been synthesized and characterized by elemental analysis, conductivity, ESI-mass, NMR and UV-Vis spectroscopies, cyclic voltammetry, X-ray diffraction ([Cu(I)(2,2′-biquinoline)(bppe)](ClO4)) and DFT calculations. These compounds are monometallic species in a distorted tetrahedral arrangement, in contrast with related compounds found as dinuclear according to diffraction studies. The spectroscopic properties are not directly correlated with the length of alkyl chain bridge between the bis-diphenylphosphine groups. In this way, the chemical shift of some 2,2′-biquinoline protons and the metal to ligand charge transfer (Cu to 2,2′-biquinoline) follows the order [Cu(2,2′-biquinoline)(bppm)](ClO4), [Cu(2,2′-biquinoline)(bppb)](ClO4), [Cu(2,2′-biquinoline)(bppe)](ClO4). The same dependence is followed by the potentials to Cu(II)/Cu(I) couple. These results are discussed in terms of inter-phosphorus alkane chain length and tetrahedral distortions on copper.  相似文献   

19.
The synthesis of new zirconium and hafnium mixed ligand phthalocyanine complexes PcM(β-ketoester)2, where M-Zr (IV), Hf (IV); Pc - the dianion of phthalocyanine, and β-ketoester - the out planed ligand, is reported. The obtained complexes are characterized by 1H NMR, IR, UV-Vis spectroscopy and cyclic voltammetry. 1H NMR and elemental analysis confirm the substitution of two Cl atoms for two β-ketoester fragments to the central atom of the macrocycle. The data of 1H NMR, UV-Vis spectroscopy have allowed us to conclude that two β-ketoester ligands are in the cis geometry to the phthalocyanine plane. X-ray crystallography for bis(isopropyl 3-oxobutanoato)hafnium(IV)phthalocyanine confirms this conclusion. The central macrocycle of the phthalocyanine ligand is not exactly planar (deviations from the least-square plane exceed 0.15 Å) and has the conformation of an essentially flattened crown. The Hf(1) atom is 1.349(3) above this least-square plane. Cyclic voltammetry investigation shows that the introduction of two β-ketoester ligands to the central atom of phthalocyanine complex leads to both chemical and electrochemical stabilization of the whole Pc system.  相似文献   

20.
The stable binaphthol-titanium ladder complexes have been successfully prepared by using bulky alkoxo ligands. From the secondary OR ligand (cyclohexyloxo, 2,4-dimethyl-3-pentyloxo or 2-adamantyloxo) and terially OR ligand (tert-butyloxo, 1-adamantyloxo), partial hydrolysis proceeded to give the μ3-oxo titanium complexes. The use of [Ti(BINOLato)(OEt)2]n made it possible to prepare the Ti(BINOLato)(OR)2 complexes using alcohols (ROH) of high boiling point (R = cyclohexyl, 2-adamantyl, 1-adamantyl). X-ray analyses of [(R)-1,1′-bi-2-naphtholato]bis(O-2,4-dimethyl-3-pentyloxo)titanium and [(R)-3,3′-dimethyl-1,1′-bi-2-naphtholato]bis(2-adamantyloxo)titanium showed a good agreement with the estimated ladder complexes. The catalytic activity of BINOL-Ti catalyst analogues, obtained by partial hydrolysis of Ti(BINOLato)(OR)2 with wet MS 4A was studied in asymmetric glyoxylate-ene reaction by two methods. Moderate to good chemical yields and enantioselectivities were obtained.  相似文献   

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