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1.
The reactions of oxovanadium(iv) salts with dimethylmalonate anions (H2Dmm — C3H6(COOH)2) and chelating N-donor ligands (2,2′:6′,2″-terpyridine (terpy), 2,2′-bipyridine (bpy)) led to the formation of new mononuclear heterochelate complexes [VO(Dmm)(terpy)]·4H2O (1) and [VO(Dmm)(bpy)(H2O)] (2). The structures of the synthesized compounds were determined by X-ray diffraction. The ESR spectra of the compounds at 293 and 100 K were analyzed and simulated. The photoluminescence properties were investigated.  相似文献   

2.
The hydrothermal reaction of Cd(II) salt with 5-[(2-methyl-1H-imidazol-1-yl)methyl]isophthalic acid (H2L) leads to the formation of a new complex [Cd(L)(H2O)] (1). While in the presence of 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) as auxiliary ligands, complexes [Cd(L)(bpy)]?H2O (2) and [Cd(L)(phen)]?2H2O (3) were obtained. Complexes 1–3 have been characterized by single crystal and powder X-ray diffractions, IR, and elemental and thermogravimetric analyzes. As a result, complex 1 exhibits twofold interpenetrated 3-D (10,3)-a architecture, 2 displays chain structure, and 3 shows uninodal 3-connected hcb network with (63) topology. The impact of auxiliary ligands on the structures of resultant complexes is discussed. Moreover, luminescence property of 1–3 was investigated.  相似文献   

3.
Vanadium(V) complexes with hydrazone-based ONO and ONN donor ligands that partly model active-site structures of vanadate-dependent haloperoxidases have been reported. On reaction with [VO(acac)2] (Hacac = acetylacetone) under nitrogen, these ligands generally provide oxovanadium(IV) complexes [VO(ONO)X] (X = solvent or nothing) and [VO(acac)(ONN)], respectively. Under aerobic conditions, these oxovanadium(IV) species undergo oxidation to give oxovanadium(V), dioxovanadium (V) or μ-oxobisoxovanadium(V) species depending upon the nature of the ligand. Anionic and neutral dioxovanadium(V) complexes slowly deoxygenate in methanol to give monooxo complexes [VO(OMe)(MeOH)(ONO)]. The anionic complexes [VO2(ONO)]- can also be convertedin situ on acidification to oxohydroxo complexes [VO(OH)(HONO)]+ and to peroxo complexes [VO(O2)(ONO)]-, and thus to the species assumed to be intermediates in the haloperoxidases activity of the enzymes. In the presence of catechol (H2cat) and benzohydroxamic acid (H2bha), oxovanadium (IV) complexes, [VO (acac)(ONN)] gave mixed-chelate oxovanadium(V) complexes [VO(cat)(ONN)] and [VO(bha)(ONN)] respectively. These complexes are not very stable in solution and slowly convert to the corresponding dioxo species [VO2(ONN)] as observed by51V NMR and electronic absorption spectroscopic studies.  相似文献   

4.
Six new μ-phthalato binuclear oxovanadium(IV) complexes, namely [(VO)2(PHTH)-(L)2]SO4 (L denotes 2,2′-bipyridine (bpy); 1,10-phenanthroline (phen); 4,4′-dimethyl-2,2′-bipyridine (Me2 bpy); 5-nitro-1,10-phenanthroline (NO2-phen); 5-chloro-1,10-phenanthroline (Cl-phen) and 5-methyl-1,10-phenanthroline (CH3-phen), where PHTH is the phthalate dianion), have been synthesized and characterized by elemental analyses, IR, electronic spectra, magnetic moments at room temperature and molar conductivity measurements. The temperature dependence of the magnetic susceptibility of complexes [(VO)2(PHTH)(phen)2]SO4 (1) and [(VO)2(PHTH)(CH3-phen)2]SO4 (2) was measured in 4—300 K range and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, ?=?2J?1·?2, giving the exchange integrals J=?12.8 cm?1 for 1 and J=?7.9 cm?l for 2. This indicates an antiferromagnetic spin-exchange interaction between the metal ions within each molecule.  相似文献   

5.
Two new CdII complexes, [Cd( ces )(phen)] ( 1 ) and {[Cd( ces )(bpy)(H2O)](H2O)}2 ( 2 ), were prepared by slow solvent evaporation methods from mixtures of cis‐epoxysuccinic acid and Cd(ClO4)2 · 6H2O in the presence of phen or bpy co‐ligand ( ces = cis‐epoxysuccinate, phen = 1,10‐phenanthroline, and bpy = 2,2′‐bipyridine). Single‐crystal X‐ray diffraction analyses show that complex 1 has a one‐dimensional (1D) helical chain that is further assembled into a two‐dimensional (2D) sheet, and then an overall three‐dimensional (3D) network by the interchain C–H ··· O hydrogen bonds. Complex 2 features a dinuclear structure, which is further interlinked into a 3D supramolecular network by the co‐effects of intermolecular C–H ··· O and C–H ··· π hydrogen bonds as well as π ··· π stacking interactions. The structural differences between 1 and 2 are attributable to the intervention of different 2,2′‐bipyridyl‐like co‐ligands. Moreover, 1 and 2 exhibit intense solid‐state luminescence at room temperature, which mainly originates from the intraligand π→π* transitions of aromatic co‐ligands.  相似文献   

6.
Four new complexes, [Zn(btca)(2,2′‐bpy)] ( 1 ), [Mn(btca)(2,2′‐bpy)] ( 2 ), [Co(btca)(phen)] ( 3 ), and [Cu(btca)(phen)] ( 4 ), (H2btca=benzotriazole‐5‐carboxylic acid, 2,2′‐bpy=2,2′‐bipyridine, phen=1,10‐phenanthroline), were successfully synthesized and characterized by elemental analysis, single crystal X‐ray diffraction, and IR spectroscopy. Complexes 1 – 4 crystallize in the orthorhombic system with space group of Pbca and show similar 2D layers, which are interlinked to supramolecular networks by π‐π stacking interactions. Furthermore, TGA curves show that complexes 1 – 4 have good thermal stability. Solid‐state fluorescent property of complex 1 was also investigated at room temperature.  相似文献   

7.
Four novel oxovanadium(IV) binuclear complexes have been synthesized, namely [(VO)2(IPHTA) (L)2SO4 (L denotes 2,2′-bipyridine (bpy); 1,10-phenanthroline (phen); 4,4′-dimethyl-2,2′-bipyridine (Me2bpy) and 5-nitro-1,10-phenanthroline (NO2-phen)), where IPHTA is the isophthalate dianon. Based on elemental analyses, molar conductivity measurements, IR and electronic spectra studies, it is proposed that these complexes have IPHTA-bridged structures and consist of two vanadium(IV) atoms in a square-pyramidal environment. The complexes [(VO)2(IPHTA)(Me2bpy)2]SO4 (1) and [(VO)2(IPHTA)(bpy)2]SO4 (2) were characterized by variable temperature magnetic susceptibility (4–300 K) and the data could be well fitted by the least-squares method to a susceptibility equation derived from the spin Hamiltonian operator, . The exchange integral, J, was found to be −26.8 cm−1 for (1) and −31.0 cm−1 for (2). These results are commensurate with antifferomagnetic interactions between two oxovanadium(IV) ions within each molecule. The influence of different terminal ligands on magnetic interactions between the metals of this kind of complexes is also discussed.  相似文献   

8.
Four new transition metal coordination polymers, [Co(bpndc)(phen)(H2O)]n ( 1 ), [Co3(bpndc)3(2,2′‐bpy)2]n·0.5n(i‐C3H7OH) ( 2 ), and [M(bpndc)(2,2′‐bpy)2]n (M = Zn, 3 ; Cu, 4 ; H2bpndc = benzophenone ‐4,4′‐dicarboxylic acid; phen = 1,10‐phenanthroline; 2,2′‐bpy = 2,2′‐bipyridine) have been synthesized by the hydrothermal reactions and characterized by single crystal X‐ray diffraction, elemental analysis, and IR spectrum. Because of the introduction of different terminal auxiliary ligands, bpndc ligands in complexes 1 and 2 adopt different coordination modes. In complex 1 , bpndc ligands act as tridentate ligand and bridge CoII ions into 1D double‐stranded chains; while complex 2 possesses 2D (4,4) grids, where bpndc ligands adopt tetradente and pentadentate modes. Two such grids interpenetrate to form a novel catenane‐like layer. Complexes 3 and 4 are isostructural. Bpndc ligands adopt tetradentate mode and bridge metal ions forming 1D helical chains.  相似文献   

9.
Four new coordination compounds, [Zn(dba)(bpy)]n (1), {[Zn(dba)(phen)]·2H2O}n (2), [Cd(dba)(bpy)(H2O)2] (3) and [Cd2(dba)2(phen)2]n (4) (H2dba = 2,5-dihydroxy-p-benzenediacetic acid, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline) have been prepared via solvothermal method and characterized by sin-gle-crystal X-ray diffraction, infrared spectroscopy, elemental analysis and powder X-ray diffraction. 1 and 2 possess 1D infinite chain structures. Complex 3 exhibits a mononuclear structure. Complex 4 owns bi...  相似文献   

10.
Two binary and two ternary mono‐oxovanadium (IV) complexes of acetylacetonate, curcumin and N ,N ′‐bis(2‐pyridyl)thiourea were synthesized. They were characterized using elemental analysis, infrared and UV–visible spectroscopies and magnetic and conductivity measurements. The formation constants K f were determined from spectrophotometric measurements. The catalytic potential of the VO complexes was investigated for the oxidation of 1‐octene by aqueous H2O2 in acetonitrile. They display high catalytic potential for the conversion of 1‐octene with low chemoselectivity to the epoxy product. The VO complexes exhibit good antibacterial and antimicrobial activities. The antioxidant activity of the VO complexes and their ligands was investigated. The VO complexes show high DNA affinity and DNA cleavage ability.  相似文献   

11.
Four new platinum(II) complexes [Pt(dpen)(bpy)](ClO4)2 ( 1 ) , [Pt(dpen)(phen)](ClO4)2 ( 2 ), [Pt(dpen)(dpq)](ClO4)2 ( 3 ) and [Pt(dpen)(dppz)](ClO4)2 ( 4 ) comprising of different N,N‐donor ligands, viz., 2,2′‐bipyridine (bpy), 1,l0‐phenanthroline (phen), dipyridoquinoxaline (dpq), dipyrido‐[3,2‐d:2¢,3¢‐f –phenazine] (dppz), and chiral ancillary ligand 1R,2R ‐1,2‐diphenylethylenediamine (dpen) have been synthesized and characterized. The interaction of these complexes 1–4 with calf‐thymus DNA (CT‐DNA) has been explored using absorption, circular dichroism spectral and cyclic voltammetric studies. The absorption spectrum of complex 4 with dppz ligand exhibits a major red shift with an overall hypochromic as well as a hyperchromic effect in the presence of DNA, other complexes ( 1 – 3 ) show only hypochromism. From these absorption spectral studies, the intercalative ability of the complexes follows the order as, 4  >  3  >  2  >  1 , which is further confirmed by CD and cyclic voltammetry measurements. CD spectral studies show that DNA becomes more A ‐like upon interaction with the complexes 1 & 2 but the complexes 3 & 4 bring about B ‐form to Z ‐ form DNA conformational transition. The DNA cleavage study of these Pt(II) complexes 1–4 carried out by gel electrophoresis revealed that complexes 1–4 can cleave super coiled (SC) pUC18 DNA efficiently into open circular form (form II) under hydrolytic and oxidative conditions.  相似文献   

12.
Oxidative addition of 2‐phenylethylbromide (PhCH2CH2Br) to dimethylplatinum(II) complexes [PtMe2(NN)] ( 1a , NN = 2,2′‐bipyridine (bpy); 1b , NN = 1,10‐phenanthroline (phen)) afforded the new organoplatinum(IV) complexes [PtMe2(Br)(PhCH2CH2)(bpy)], as a mixture of trans ( 2a ) and cis ( 3a ) isomers, and [PtMe2(Br)(PhCH2CH2)(phen)], as a mixture of trans ( 2b ) and cis ( 3b ) isomers, respectively. The new Pt(IV) complexes were readily characterized using multinuclear (1H and 13C) NMR spectroscopy and elemental microanalysis. The crystal structure of 2a was further determined using X‐ray crystallography indicating an octahedral geometry around the platinum centre. A comparison of reactivity of RCH2Br reagents (R = CH3, Ph or PhCH2) in their oxidative addition reactions with complex 1a , with an emphasis on the effects of the R groups of alkyl halides, was also conducted using density functional theory.  相似文献   

13.
A novel ligand 3‐(1H‐imidazo[4,5‐f][1,10]phenanthrolin‐2‐yl)‐4H‐1‐benzopyran‐4‐one (ipbp) and its ruthenium(II) complexes [Ru(bpy)2(ipbp)]2+ ( 1 ) and [Ru(ipbp)(phen)2]2+ ( 2 ) (bpy=2,2′‐bipyridine, phen=1,10‐phenanthroline) were synthesized and characterized by elemental analysis and mass, 1H‐NMR, and electronic‐absorption spectroscopy. The electrochemical behavior of the complexes was studied by cyclic voltammetry. The DNA‐binding behavior of the complexes was investigated by spectroscopic methods and viscosity measurements. The results indicate that complexes 1 and 2 bind with calf‐thymus DNA in an intercalative mode. In addition, 1 and 2 promote cleavage of plasmid pBR 322 DNA from the supercoil form I to the open circular form II upon irradiation.  相似文献   

14.
The role of ancillary ligands, namely imidazole (im), pyridine (py), 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) in the assembly of copper(II) dipicolinate complexes are presented. Mononuclear complexes are observed in the case of monodentate ligands. The mononuclear complex [Cu(im)3L]·4H2O (1) (L = dipicolinate anion) has a distorted octahedral structure with Z′ = 2, whereas [CuL(py)(H2O)]·2H2O (2) adopts distorted square pyramidal geometry. The bidentate ligands bpy and phen favor the formation of dinuclear complexes. The dinuclear complex [CuL(bpy)(μ-L)Cu(bpy)(H2O)]·9H2O (3) has one carbonyl oxygen atom of a carboxylate group of dipicolinate acting as a bridging ligand to the copper site that is devoid of a coordinated water molecule. The complex has an angle of 83.55° between the plane of L and bpy attached to one copper site, whereas it has an angle of 78.13° between the plane L and bpy attached to the other copper site. A 1,10-phenanthroline containing dinuclear copper(II) dipicolinate complex, [Cu(phen)(H2O)(μ-L)Cu(phen)2][CuL2]·12H2O (4), has been structurally characterized. It has an unusual carboxylate bridge.  相似文献   

15.
Reactions of aquapentachloroplatinic acid, (H3O)[PtCl5(H2O)]·2(18C6)·6H2O ( 1 ) (18C6 = 18‐crown‐6), and H2[PtCl6]·6H2O ( 2 ) with heterocyclic N, N donors (2, 2′‐bipyridine, bpy; 4, 4′‐di‐tert‐butyl‐2, 2′‐bipyridine, tBu2bpy; 1, 10‐phenanthroline, phen; 4, 7‐diphenyl‐1, 10‐phenanthroline, Ph2phen; 2, 2′‐bipyrimidine, bpym) afforded with ligand substitution platinum(IV) complexes [PtCl4(N∩N)] (N∩N = bpy, 3a ; tBu2bpy, 3b ; Ph2phen, 5 ; bpym, 7 ) and/or with protonation of N, N donor yielding (R2phenH)2[PtCl6] (R = H, 4a ; Ph, 4b ) and (bpymH)+ ( 8 ). With UV irradiation Ph2phen and bpym reacted with reduction yielding platinum(II) complexes [PtCl2(N∩N)] (N∩N = Ph2phen, 6 ; bpym, 9 ). Identities of all complexes were established by microanalysis as well as by NMR (1H, 13C, 195Pt) and IR spectroscopic investigations. Molecular structures of [PtCl4(bpym)]·MeOH ( 7 ) and [PtCl2(Ph2phen)] ( 6 ) were determined by X‐ray diffraction analyses. Differences in reactivity of bpy/bpym and phen ligands are discussed in terms of calculated structures of complexes [PtCl5(N∩N)] with monodentately bound N, N ligands (N∩N = bpy, 10a ; phen, 10b ; bpym, 10c ).  相似文献   

16.
Six complexes, [VO(L1-H)2]?·?5H2O (1), [VO(OH)(L2,3?H)(H2O)]?·?H2O (2,3), [VO(OH)(L4,5?H)(H2O)]?·?H2O (4,5), [VO(OH)(L6?H)(H2O)]?·?H2O (6), were prepared by reacting different derivatives of 5-phenylazo-6-aminouracil ligands with VOSO4?·?5H2O. The infrared and 1H NMR spectra of the complexes have been assigned. Thermogravimetric analyses (TG, DTG) were also carried out. The data agree quite well with the proposed structures and show that the complexes were finally decomposed to the corresponding divanadium pentoxide. The ligands and their vanadyl complexes were screened for antimicrobial activities by the agar-well diffusion technique using DMSO as solvent. The minimum inhibitory concentration (MIC) values for 14 and 6 were calculated at 30°C for 24–48?h. The activity data show that the complexes are more potent antimicrobials than the parent ligands.  相似文献   

17.
Novel mononuclear mixed-ligand oxovanadium(IV) complex [VO(PMFP)(Bipy)]ClO4 was prepared by the condensation of VOSO4 · 5H2O with ligands 1-phenyl-3-methyl-4-formyl-2-pyrazolin-5one (PMFP) and 2,2′-bipyridyl (Bipy). The corresponding Schiff bases were prepared by the condensation of [VO(PMFP)(Bipy)]ClO4 with ethylenediamine, ethanolamine, and glycine. All the compounds have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, 1H NMR, FT-IR, ESR, electronic spectra, and mass spectrometry. Electronic spectra and magnetic susceptibility measurements indicate distorted octahedral stereochemistry of the oxovanadium(IV) complexes. Thermal stability, kinetic order, heat capacity, and activation energy of thermal degradation of these complexes were determined by TGA and DSC. The presence of one coordinate water molecule is suggested from the IR and TGA studies. Hamiltonian and bonding parameters were found from ESR spectra, indicating that the metal-ligand bonding is partial covalent. Antibacterial screening is reported for the ligand and complexes of oxovanadium(IV). The text was submitted by the authors in English.  相似文献   

18.
Five oxovanadium(IV) dinuclear complexes described by the overall formula [(VO)2(IA)L2SO4, where IA repents the dianion of iodanilic acid and L denotes 2, 2′-bipyridine (bpy); 4,4′-dimethy12,2′-bipyridine (Meo-bpy); 1,10-phenanthroline (phen); 4,7-diphenyl-l, 10-phenanthroline (Ph2-phen) and 5-nitro-1, 10-phenanthroline (NO2-phen), have been synthesized and characterized by elemental analyses, molar conductivity and roomtemperature magnetic moment measurements, IR and electronic spectral studies. It is proposed that these complexes have IA-bridged structures and consist of two oxovanadium(IV) ions each in a square pyramidal environment. The complexes (VO)2(IA) (bpy)2]SO4, (1) and[(VO)2( IA) (phen)2 ]SO4 (2) were further characterized by variable temperature (4.2–300 K) magnetic susceptibility measurements and the observed data were fitted to the modified Bleaney-Bowers equation by the least-squares method, giving the exchange integral J = - 2.15 m?1 for 1 and J = - 9.88 cm?1 for 2. This result indicates that there is a weak antiferromagnetic spin-exchange interaction between the two VO2+ ions within each molecule.  相似文献   

19.
Two new mixed ligand complexes of copper(II) with acetylacetonate (acac), 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) belonging to the class of cytotoxic and antineoplastic compounds known as CASIOPEINAS® were synthesized and structurally characterized. Crystals of both complexes [Cu(acac)(bpy)(H2O)]NO3 · H2O (1), [Cu(acac)(phen)Br] (2) contain square pyramidal Cu(II) complex species. In frozen solution both compounds give well resolved EPR spectra with very similar parameters.  相似文献   

20.
Diorganotin (IV) complexes SnR2X2 (R = Me, Ph; X = Cl, NCS) form a series of versatile complexes when react with bidentate substituted pyridyl ligands. The reaction of dimethyltin dichloride with 5,5′‐dimethyl‐2,2′‐bipyridine (5,5′‐Me2bpy) resulted in the formation of [SnMe2Cl2(5,5′‐Me2bpy)] ( 1 ). Moreover, the reaction of SnMe2(NSC)2 with 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine (bu2bpy), 1,10‐phenanthroline (phen) and 4,7‐diphenyl‐1,10‐phenanthroline (bphen) affords the hexa‐coordinated complexes [SnMe2(NCS)2(bu2bpy)] ( 2 ), [SnMe2(NCS)2(phen)] ( 3 ) and [SnMe2(NCS)2(bphen)] ( 4 ), respectively. The resulting complexes have been characterized using elemental analysis, IR, multinuclear NMR (1H, 13C, 119Sn) and DEPT‐135° NMR spectroscopy. On the other hand, the reaction of diphenyltin dichloride with 2,2′‐biquinoline (biq) and 4,7‐phenantroline (4,7‐phen) led to the formation of polymeric complexes of [SnPh2Cl2(4,7‐phen)]n ( 5 ) and [SnPh2Cl2(biq)]n ( 6 ). The NMR spectra, however, reveal the ligand lability in solution and suggest a coordination number of 5 . The X‐ray crystal structures of complexes [SnMe2Cl2(5,5′‐Me2bpy)] ( 1 ), [SnMe2(NCS)2(bu2bpy)] ( 2 ) and [SnMe2(NCS)2(bphen)] ( 4 ) have been determined which reveal that the geometry around the tin atom is distorted octahedral with trans‐[SnMe2] configuration. Interestingly, the crystal structure of (H2biq)2[SnPh2Cl4]?2CHCl3 ( 7 ) was characterized by X‐ray crystallography from a chloroform solution of [SnPh2Cl2(biq)]n ( 6 ) indicating the formation of doubly protonated [H2biq]+ and [Ph2SnCl4]2? which are stabilized by a network of hydrogen bonds with a feature of trans‐[SnPh2]. The 3D Hirshfeld surface analysis and 2D fingerprint maps were used for quantitative mapping out of the intermolecular interactions for 1 , 2 , 4 and 7 which show the presence of π‐π and hydrogen bonding interactions which are associated between donor and acceptor atoms (N, S, Cl) in the solid state.  相似文献   

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