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1.
A pair of structurally similar dioxomolybdenum(VI) complexes with general formula [MoO2(L)(MeOH)] (L = L1 = N’-(3,5-dibromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide for I, L = L2 = N’-(3,5-dibromo-2-hydroxybenzylidene)-2-methylbenzohydrazide for II), have been prepared and characterized by elemental analysis, IR spectra, and single crystal X-ray determination (CIF files CCDC nos. 917823 (I) and 917824 (II)). The hydrazone ligands coordinate to the Mo atoms through phenolate oxygen, imine nitrogen, and enolic oxygen atoms. The Mo atom in each complex is six-coordinated in an octahedral geometry. The crystals of the complexes are stabilized by hydrogen bonds. The complexes and the ligands were assayed for antibacterial activities against three Gram-positive bacterial strains (B. subtilis, S. aureus, and S. faecalis) and three Gram-negative bacterial strains (E. coli, P. aeruginosa, and E. cloacae) by MTT method. As a result, the complexes showed effective antimicrobial activity against the microorganisms tested.  相似文献   

2.
A series of dioxomolybdenum(VI) complexes with similar hydrazone ligands have been prepared, specifically [MoO2L1(MeOH)] (1), [MoO2L2(MeOH)] (2) and [MoO2L3(MeOH)] (3), where L1, L2 and L3 are the dianionic forms of 2-chloro-N′-(2-hydroxybenzylidene)benzohydrazide, 2-chloro-N′-(2-hydroxy-5-methylbenzylidene)benzohydrazide and N′-(3-bromo-5-chloro-2-hydroxybenzylidene)-2-chlorobenzohydrazide, respectively. The complexes were characterized by physicochemical and spectroscopic methods and also by single-crystal X-ray determination. The hydrazone ligands coordinate to the Mo atoms through their phenolate O, imine N and enolic O atoms. The Mo atoms are six-coordinated in octahedral geometries. The complexes show high catalytic activities and selectivities in the epoxidation of cyclohexene with tert-butylhydroperoxide as primary oxidant.  相似文献   

3.
The preparation of Mo(VI) hydrazone complexes, cis-[MoO2L1(CH3OH)] (I) and cis-[MoO2L2(CH3OH)] (II), derived from N'-(3-bromo-2-hydroxybenzylidene)-2-chlorobenzohydrazide (H2L1) and N'-(3-bromo-2-hydroxybenzylidene)-4-bromobenzohydrazide (H2L2), respectively, is reported. The complexes were characterized by elemental analyses, infrared and electronic spectroscopy, and single crystal structure analysis (CIF files ССDС nos. 1426875 (I), 1426871 (II)). The Mo atoms are coordinated by two cis terminal oxygen, ONO from the hydrazone ligand, and methanol oxygen. Even though the hydrazone ligands and the coordination sphere in both complexes are similar, the unit cell dimensions and the space groups are different. Complex I crystallized as orthorhombic space group Pca21 with unit cell dimensions a = 27.887(2), b = 8.0137(7), c = 15.544(1) Å, V = 3473.8(5) Å3, Z = 8, R 1 = 0.0450, wR 2 = 0.0539. Complex II crystallized as triclinic space group P1, with unit cell dimensions a = 8.2124(4), b = 8.5807(5), c = 12.9845(8) Å, α = 83.366(2)°, β = 79.201(2)°, γ = 80.482(2)°, V = 883.03(9) Å3, Z = 2, R 1 = 0.0278, wR 2 = 0.0569. The complexes were tested as catalyst for the oxidation of olefins, and showed effective activity.  相似文献   

4.
Two Mo(VI) aroylhydrazone complexes, cis-[MoO2(L1)(CH3OH)] (I) and cis-[MoO2(L2)(CH3OH)] (II), derived from 2-bromo-N'-(3,5-dibromo-2-hydroxybenzylidene)benzohydrazide (H2L1) and 2-bromo-N'-(2-hydroxy-4-methoxybenzylidene)benzohydrazide (H2L2), respectively, are reported. The complexes were characterized by elemental analyses, infrared and electronic spectroscopy, and single crystal structure analysis (CIF files CCDC nos. 1443679 (I) and 1443678 (II)). The Mo atoms are coordinated by two cis terminal oxygen, ONO from the aroylhydrazone ligand, and methanol oxygen. Complex I crystallized as monoclinic space group P21/c with unit cell dimensions a = 8.075(2), b = 13.905(1), c = 16.448(1) Å, β = 91.282(2)°, V = 1846.5(4) Å3, Z = 4, R 1 = 0.0859, wR 2 = 0.2066. Complex II crystallized as triclinic space group P \(\overline 1 \), with unit cell dimensions a = 8.0824(6), b = 10.5919(8), c = 10.7697(8), α = 96.432(2)°, β = 97.438(2)°, γ = 103.119(2)°, V = 880.8(1) Å3, Z = 2, R 1 = 0.0271, wR 2 = 0.0571. The complexes were tested as catalyst for the oxidation of olefins and showed effective activity.  相似文献   

5.
Fifteen new complexes of transition metals were designed using three Schiff base ligands and aldol condensation of 2,3-diaminopyridine with 5-R-2-hydroxybenzaldehyde (R = F, Cl, Br) in the 1:2 molar ratio. The tetradentate ligands N,N′-bis(5-R-2-hydroxybenzaldehyde) pyridine were acquired with the common formula H2[(5-R-sal)2py] and characterized by IR, UV–Vis spectra, 1H-NMR and elemental analysis. These ligands produce 1:1 complexes M[(5-R-sal)2py] with Fe(III), Ni(II), Co(III), V(IV) and U(VI) metal ions. The electronic property and nature of complexes were identified by IR, UV–Vis spectra, elemental analysis, X-ray crystallography and cyclic voltammetric methods. The catalytic activity of complexes for epoxidation of styrene with UHP as primary oxidant at minimal temperature (10 °C) has been planned. The spectral data of the ligands and their complexes are deliberate in connection with the structural changes which happen due to complex preparation. The electrochemical outcome has good conformability with what suggested for electronic interaction among metal center and ligand by the UV–Vis and IR measurements.  相似文献   

6.
Complexes of NiII with new ligands N′,N′′-bis(3-carboxy-1-oxoprop-2-enyl), 2-Amino-N-arylbenzamidine (C21H17N3O6), N′,N′′-bis(3-carboxy-1-oxopropanyl) 2-Amino-N-arylbenzamidine (C21H21N3O6) and N′,N′′-bis(3-carboxy-1- oxophenelenyl) 2-Amino-N-arylbenzamidine (C29H21N3O6) have been synthesized and characterized by elemental analyses, vibrational spectra, electronic spectra, TOF-mass spectra, magnetic susceptibility measurements, thermal studies and X-ray powder diffraction studies. Vibrational spectra indicate coordination of amide and carboxylate oxygen of the ligands along with two water molecules giving a MO6 weak field octahedral chromophore. Electronic spectra and magnetic susceptibility measurements reveal octahedral geometry for NiII complexes. The elemental analyses and mass spectral data have justified the ML complexes. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redfern method, which confirm first order kinetics. The crystal data: C21H19N3O8 Ni is orthorhombic, space group Pmmm, a = b = 9.015360(Å), c = 10.554430(Å), V = 572.11A3; C21H23N3O8Ni is monoclinic, space group P2/m, a = 15.08206(Å), b = 5.358276(Å), c = 9.898351(Å), V = 671.58A3; C29H23N3O8Ni is tetragonal, space group P4/m, a = b = 6.328104(Å), c = 9.82213(Å), V = 393.33A3. Molecular structures of the complexes have been optimized by MM2 calculations and supported octahedral arrangements around Nickel(II) ions.  相似文献   

7.
Two new dioxomolybdenum(VI) complexes, [MoO2L1(MeOH)] (I) and [MoO2L2] (II), where L1 and L2 are the anionic forms of N'-(2-hydroxy-3,5-di-tert-butylbenzylidene)-4-methoxybenzohydrazide and 2-amino-N'-(2-hydroxy-3,5-di-tert-butylbenzylidene)benzohydrazide, respectively, have been synthesized and characterized by elemental analysis, FT-IR spectra, and single crystal X-ray determination (CF files CCDC nos. 1448089 (I), 1487063 (II)). The crystal of I is monoclinic: space group P21/n, a = 7.353(1), b = 24.758(3), c = 13.891(2) Å, β = 101.013(2)°, V = 2482.3(6) Å3, Z = 4, R 1 = 0.0848, wR 2 = 0.2050. The crystal of II is monoclinic: space group P21/c, a = 6.752(1), b = 16.947(1), c = 19.510(1) Å, β = 96.891(2)°, V = 2216.5(4) Å3, Z = 4, R 1 = 0.0670, wR 2 = 0.1638. The Mo atom in complex I is in octahedral coordination, with three donor atoms of the hydrazone ligand, two oxo groups, and one methanol O atom. The Mo atom in complex II is in square pyramidal coordination, with three donor atoms of the hydrazone ligand, and two oxo groups. The complexes have interesting catalytic properties for sulfoxidation reactions.  相似文献   

8.
The structural features of 39 mononuclear octahedral d 2-rhenium(V) monooxo complexes (I–ХХХIХ) with oxygen atoms of bidentate-chelating (O,O) acido ligands (Lig) are considered. In 21 complexes (I–ХХI), the O(lig) atoms are both in trans and cis positions to oxo ligands. In the other 18 complexes (XXI–XXXIX), both O(lig) atoms are in cis positions to the O(oxo) ligands.  相似文献   

9.
A pair of Mo(VI) complexes, [MoO2L1(MeOH)] (1) and [MoO2L2(MeOH)] (2), where L1 and L2 are the dianions of 2-amino-N’-(3-bromo-5-chloro-2-hydroxybenzylidene)benzohydrazide (H2L1) and 2-amino-N’-(3,5-dibromo-2-hydroxybenzylidene)benzohydrazide (H2L2), respectively, have been prepared and characterized by physico-chemical methods and single-crystal X-ray diffraction. The Mo atom in each complex is coordinated by the phenolate oxygen, imino nitrogen and enolate oxygen of the hydrazone ligand, together with a methanol ligand and two oxo groups, giving a distorted octahedral geometry. The complexes proved to be effective catalysts for the oxidation of various olefins.  相似文献   

10.
The structural features of 38 mononuclear d 2-Re(V) octahedral monooxo complexes (I–XXXVIII) with oxygen atoms of bidentate-chelating (O, P) ligands (L n ) are considered. The atoms O(L n ) are mostly in trans positions to O(oxo) ligands. In three compounds of general formula [ReO(Lmono)(L n )2] (XXXVI–XXXVIII), the O atoms of two L n ligands occupy both trans and cis positions to oxo ligands. In one complex, namely, in [ReO(L n )(L tri 11 )], n = 3 (XXXV), the atom O(L3) is in the cis position to the oxo ligand; the trans position to O(oxo) is occupied by the atom O(L tri 11 ).  相似文献   

11.
Polyisoprene with relatively high content of 1,2/3,4 structure was synthesized using a novel catalyst system composed of MoO2Cl2 supported by phosphorus ligand and Al(OPhCH3)(i-Bu)2 as co-catalyst. The effects of phosphites, phosphates and phosphoric acid as ligands were investigated in the coordination polymerization of isoprene in the chosen catalyst system. The studied ligands significantly affected the catalytic activity of the Mo–Al catalytic active center without significant effect on the stereoselectivity. Mo(VI)-based catalyst system was proved to be highly effective in the polymerization of isoprene even at low [Al]/[Mo] ratio (10), affording polyisoprene with 1,2- and 3,4-% structural units in the range of 44.6–52.5%, high molecular weights Mn ~ 105, and relatively broad molecular weight distributions (Mw/Mn = 3.0–4.4). The effect of molar ratio of phosphorous ligand to Mo-catalyst on catalyst activity of isoprene polymerization was discussed, and the structures of Mo–phosphite complexes were preliminarily studied by IR.  相似文献   

12.
Two methanol coordinated zinc(II) complexes, [Zn(L1)(MeOH)] (I) and [Zn(L2)(MeOH)] (II), where L1 and L2 are the dianionic form of N,N'-bis(5-fluorosalicylidene)ethane-1,2-diamine and N,N'-bis(5-fluorosalicylidene)propane-1,2-diamine, respectively, have been synthesized and characterized by physical chemical methods and single crystal X-ray diffraction (CIF files CCDC nos. 950907 (I) and 950908 (II)). Crystallographic data for I: triclinic, P \(\bar 1\), a = 8.8765(8), b = 9.6577(9), c = 10.5117(9) Å, α = 114.590(2)°, β = 91.648(3)°, γ = 97.114(3)°, V = 809.87(13) Å3, Z = 2, R 1 = 0.0307, wR 2 = 0.0698. Crystallographic data for II: orthorhombic, Pca21, a = 22.946(2), b = 7.6942(7), c = 9.6234(8) Å, V = 1699.0(2) Å3, Z = 4, R 1 = 0.0320, wR 2 = 0.0676. X-ray crystal structural study indicated that the coordination environment around each zinc(II) atom in the complexes is a five-coordinated distorted pyramid in which the apical position is occupied by a methanol oxygen atom, and the basal plane is defined by the nitrogen and oxygen donor atoms of the Schiff base ligand. The antibacterial activities of the complexes were assayed.  相似文献   

13.
9-Substituted 1,2-bis(diphenylphosphanyl)-o-carboranes were synthesized from the corresponding 9-R-o-carboranes (R = I, i-Pr, SMe), and their complexes with chromium, molybdenum, and palladium were obtained. The coordination chemical shifts calculated from the 31P NMR spectra of the complexes and free ligands showed that the substituent at B9 of carborane affects the strength of the ligand-to-metal binding, but the latter is determined to a greater extent by the nature of the metal and its ligand environment.  相似文献   

14.
The complexes [Ni(L1)(pyc)2]·2H2O (1) (L1 = C-meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane; Hpyc = pyrazinecarboxylic acid) and [Cu(L2)(H-cpdc)] (2) (L2 = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane; H2-cpdc = cyclopropanedicarboxylic acid) have been synthesized and structurally characterized. The crystal structure of complex 1 shows a distorted octahedral coordination geometry around the nickel(II) center, with four secondary amines in the equatorial positions and two nitrogen atoms of the pyc? ligands in the trans positions. In complex 2, the coordination environment around the copper(II) center is a Jahn–Teller distorted octahedron with four Cu–N bonds and two axial Cu–O bonds. The electronic spectra, electrochemical and TGA behavior of the complexes are significantly affected by the nature of the axial pyc? and H-cpdc? ligands.  相似文献   

15.
New dioxomolybdenum(VI) complex [MoO2(L)(CH3OH)], where L is the dianionic form of N'- (3-bromo-5-chloro-2-hydroxybenzylidene)-4-nitrobenzohydrazide (H2L), was prepared and characterized by IR and UV-Vis spectra, as well as single crystal X-ray diffraction (CIF file ССDС no. 1567063). The complex crystallizes as the monoclinic space group P21/c with unit cell dimensions a = 13.8471(10), b = 7.5618(6), c = 17.9445(12) Å, β = 90.107(2)°, V = 1878.9(2) Å3, Z = 4, R1 = 0.0821, wR2 = 0.0907, GOOF = 1.024. X-ray analysis indicates that the complex is a dioxomolybdenum(VI) species with the Mo atom in octahedral coordination. The catalytic oxidation property of the complex with tert-butylhydroperoxide in CH2Cl2 was studied.  相似文献   

16.
Two cis-dioxomolybdenum(VI) complexes [MoO2L] (L: L 1, 2 and L: L 2, 3) in a phenol-based sterically encumbered N2O2 ligand environment have been synthesized, and their crystallographic characterizations are reported. The orange crystals of 2 are monoclinic, space group P21/a with unit cell dimensions as a=16.2407(17) Å, b=7.2857(8) Å, c=18.400(2) Å, β=98.002(9)°, Z=4, and d cal=1.486 g cm?3. The light orange crystals of 3, however, are orthorhombic, space group, Pbcn, with unit cell dimensions a=8.3110(12) Å, b=12.637(3) Å, c=34.673(5) Å, Z=4, and d cal=1.187 g cm?3. The structures were refined by a full-matrix least-squares procedure on F 2 to a final R=0.046 (0.055 for 3) using 4944 (3677) all independent data. In both the cases, the Mo atom exists in a distorted octahedral geometry defined by a N2O4 donor set, which features a cis-Mo(–O)2 and a trans-Mo(OPh)2 arrangement. Compound 2 undergoes a quasireversible one-electron reduction at ?1.3 V vs Ag/AgCl reference due to MoVIO2/MoVO2 electron transfer and thus providing a rare example of steric solution to the comproportionation–dimerization problem encountered frequently in the development of valid biomimetic models for the active sites of oxomolybdenum enzymes.  相似文献   

17.
Novel Cu(II), Co(II), Ni(II), and Zn(II) complexes of 5-methyl-2-phenyl-4-[(4-phenylazo)anilinemethylylidene]- 2,4-dihydro-3H-pyrazole-3-thione and 5-methyl-4-[4-methyl-2-(4-methylphenylazo)anilinemethylylidene]- 2-phenyl-2,4-dihydro-3H-pyrazole-3-thione, i.e. ligands containing the phenylazo group in the ortho and para positions of the aniline fragment, were synthesized by the chemical and electrochemical methods. The complexes and ligands were characterized by IR, 1H NMR, X-ray absorption spectroscopy and magnetochemistry. The azo group of the ligands is not involved in coordination to the metal.  相似文献   

18.
The crystal structures of two polymorphs of molybdenyl salicylidene-2-furfuryliminate [MoO2(L1)2] have been solved by X-ray diffraction. Both complexes crystallize in centrosymmetric and non-centrosymmetric space groups (P21/c and Р21, respectively) of monoclinic system and have similar structures and close geometric parameters. The Мо atoms have a distorted octahedral coordination to two terminal oxo ligands in cis-positions to each other and two pairs of the oxygen atoms (cis- to О(oxo)) and the nitrogen atoms (trans- to О(oxo)) of two bidentate chelate ligands (L1).  相似文献   

19.
The stability constants of complexes derived from tetraphenylporphyrinatozinc(II) and various ligands in chloroform at 25°C were proposed as nucleophilicity/basicity parameters of the latter, which reflect the effects of electronic and steric factors. Supernucleophilicity of heteroaromatic N-oxides in reactions with electrophiles was interpreted in terms of sp 2sp 3 rehybridization of the N-oxide oxygen atom.  相似文献   

20.
Cisplatin is an anticancer drug widely used in the treatment of a wide range of solid tumours (head and neck, lung, bladder etc.), testicular and ovarian cancers. Because of its severe toxicity profile and spontaneous development of drug resistance in tumours, a number of Pt(II) complexes have been synthesised and tested for anti-tumour activity. Some of the investigations have focused on using ligands bearing donor atoms other than N (e.g., S, P, O). Two new mixed Pt(II) complexes of the general formula cis-[Pt(NH3)LCl2] where L is 3-thiolanespiro-5-hydantoin and 4-thio-1H-tetrahydropyranspiro-5-hydantom were synthesised. The complexes were studied by elemental analysis, melting points, IR and 1H NMR spectra. The hybrid DFT calculations were used for optimisation of the structure geometries of the ligands III, IV and their Pt(II) complexes V and VI. The structural parameters so calculated, such as bond lengths and angles, are in good agreement with the experimental data for similar hydantoins and their platinum complexes. The results showed that the geometries of complexes V and VI are plane square and the bounding of ligands III and IV with platinum ions is effected by the sulphur atom from the cyclic ring. The complexes thus obtained were chemically examined in comparison with previously synthesised and published complexes of the general formula cis-[PtL2Cl2] (VII and VIII) with the same ligands. The new compounds V and VI, as well as the previously investigated complexes (VII and VIII), were analysed for cytotoxicity in vitro on SKW-3 and HL-60 human tumour cell lines. The results showed that all the complexes exerted concentration-dependent anti-proliferative activity.  相似文献   

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