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1.
A series of monooxo-Mo(IV,V) and dioxo-Mo(VI) complexes of the "soft" tripodal ligand, sodium tris(mercaptoimidazolyl)borate (NaTm(Me)), have been synthesized as potential oxygen atom transfer (OAT) models for sulfite oxidase. Complexes have been characterized by X-ray crystallography, cyclic voltammetry, and EPR, where appropriate. Oxygen atom transfer kinetics of Tm(Me)MoO(2)Cl, both stoichiometric and catalytic, have been studied by a combination of UV-vis and (31)P NMR spectroscopies under a variety of conditions. OAT rates are consistent with previously established relationships between redox potential/reactivity and mechanistic studies. The analysis of these complexes as potential structural and functional analogues of relevance to molybdoenzymes is further discussed. 相似文献
2.
《Journal of Inorganic and Nuclear Chemistry》1981,43(11):2919-2923
The behavior of neptunium(VI), -(V) and -(IV) in carbonate-bicarbonate buffers (1 M) has been examined electrochemically and spectroscopically. Np(VI) undergoes a one-electron quasi-reversible reduction to Np(V) at +0.22 V vs SSCE Np(V) is reduced irreversibly to Np(IV) at ca. −1.8 V. Although Np(V) is readily oxidized to Np(VI), no oxidation of Np(IV) was observed. Spectroscopic results indicate that the Np(VI)-(V) reaction involves one reactant and one product. The spectrum of Np(IV) in 1 M carbonate-bicarbonate has been quantitatively analyzed. Comparisons to results for uranium under similar conditions are presented. 相似文献
3.
Sahin M Koca A Ozdemir N Dinçer M Büyükgüngör O Bal-Demirci T Ulküseven B 《Dalton transactions (Cambridge, England : 2003)》2010,39(42):10228-10237
The stable uranyl complexes, [UO(2)(L)C(9)H(19)OH], were obtained from 3,5-dichlorosalicyl-(L(I)) and salicyl-aldehyde-S-propyl-thiosemicarbazones (L(II)) with substituted-salicylaldehyde in nonyl alcohol. The structures of the complexes have been characterized by elemental analysis, IR, (1)H NMR, conductivity, magnetic moment measurements, cyclic voltammetry, thermal gravimetric analysis and single crystal X-ray diffraction technique. The U(VI) centre is seven-coordinated in a distorted pentagonal bipyramidal geometry. The relative orientations of the nonyl alcohol and S-propyl group in the title complexes are completely different due to different crystal packing. Electrochemical behaviors of the thiosemicarbazone ligands and the uranyl complexes were studied using cyclic voltammetry and square wave voltammetry. Redox processes of the compounds are significantly influenced by the central metal ions and the nature of substituents on the thiosemicarbazones, which are important factors in controlling the redox properties. In situ spectroelectrochemical studies were employed to determine the colors and spectra of electro-generated species of the complexes. 相似文献
4.
Two equivalents of the unsymmetrical Schiff base ligand (L(tBu))(-) (4-tert-butyl phenyl(pyrrolato-2-ylmethylene)amine) and MoCl(2)(NtBu)O(dme) (dme = 1,2-dimethoxyethane) gave a single stereoisomer of a mixed imido/oxido Mo(VI) complex 2(tBu). The stereochemistry of 2(tBu) was elucidated using X-ray diffraction, NMR spectroscopy, and DFT calculations. The complex is active in an oxygen atom transfer (OAT) reaction to trimethyl phosphane. The putative intermediate five-coordinate Mo(IV) imido complex coordinates a PMe(3) ligand, giving the six-coordinate imido phosphane Mo(IV) complex 5(tBu). The stereochemistry of 5(tBu) is different from that of 2(tBu) as shown by NMR spectroscopy, DFT calculations, and X-ray diffraction. Single-electron oxidation of 5(tBu) with ferrocenium hexafluorophosphate gave the stable cationic imido phosphane Mo(V) complex [5(tBu)](+) as the PF(6)(-) salt. EPR spectra of [5(tBu)](PF(6)) confirmed the presence of PMe(3) in the coordination sphere. Single-crystal X-ray diffraction analysis of [5(tBu)](PF(6)) revealed that electron transfer occurred under retention of the stereochemical configuration. The rate of OAT, the outcome of the electron transfer reaction, and the stabilities of the imido complexes presented here differ dramatically from those of analogous oxido complexes. 相似文献
5.
Millar AJ Doonan CJ Smith PD Nemykin VN Basu P Young CG 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(11):3255-3267
Intermediates in the oxygen atom transfer from Mo(VI) to P(III), [Tp(iPr)MoOX(OPR3)] (Tp(iPr) = hydrotris(3-isopropylpyrazol-1-yl)borate; X = Cl-, phenolates, thiolates), have been isolated from the reactions of [Tp(iPr)MoO2X] with phosphines (PEt3, PMePh2, PPh3). The green, diamagnetic oxomolybdenum(IV) complexes possess local C(1) symmetry (by NMR spectroscopy) and exhibit IR bands assigned to nu(Mo==O) (approximately 950 cm(-1)) and nu(P==O) (1140-1083 cm(-1)) vibrations. The X-ray crystal structures of [Tp(iPr)MoOX(OPEt3)] (X = OC6H4-2-sBu, SnBu), [Tp(iPr)MoO(OPh)(OPMePh2)], and [Tp(iPr)MoOCl(OPPh3)] have been determined. The monomeric complexes exhibit distorted octahedral geometries, with coordination spheres composed of tridentate fac-Tp(iPr) and mutually cis monodentate terminal oxo, phosphoryl (phosphine oxide), and monoanionic X ligands. The electronic structures and stabilities of the complexes have been probed by computational methods, with the three-dimensional energy surfaces confirming the existence of a low-energy steric pocket that restricts the conformational freedom of the phosphoryl ligand and inhibits complete oxygen atom transfer. The reactivity of the complexes is also briefly described. 相似文献
6.
Jos S. Casas Eduardo E. Castellano Javier Ellena María S. García‐Tasende Agustín Snchez Jos Sordo Carmen Taboada María J. Vidarte 《应用有机金属化学》2003,17(12):940-944
The reaction of dichloroethylphenyltin(IV), Ph(Et)SnCl2, with phenanthroline monohydrate (phen·H2O) in chloroform, in 1:1 mole ratio, afforded [Ph(Et)SnCl2(phen)]. The crystal structures of dichloroethylphenyltin(IV) and its phenanthroline adduct were studied by X‐ray diffraction. In Ph(Et)SnCl2 the tin atom is in a distorted tetrahedral environment, the distortion probably being imposed by weak intermolecular Sn· · ·Cl interactions. In [Ph(Et)SnCl2(phen)] the tin atom is in an octahedral trans‐C2, cis‐Cl2, N2 environment and weak intermolecular C–H· · ·Cl interactions connect the molecules throughout the lattice. Spectroscopic studies in solution (1H, 13C and 119Sn NMR) were also carried out; the 1H and 13C NMR data in dimethylsulfoxide suggest that [Ph(Et)SnCl2(phen)] remains at least partially undissociated in this solvent. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
7.
Reaction of guaiazulene (8) with 2,3-dihydroxybenzaldehyde (9) in methanol in the presence of hexafluorophosphoric acid (i.e., 65% aqueous solution) at 25 °C for 2 h gives (3-guaiazulenyl)(2,3-dihydroxyphenyl)methylium hexafluorophosphate (13) in 86% yield. Similarly, reaction of 8 with 2-hydroxy-3-methoxybenzaldehyde (10) [or 3,4-dihydroxybenzaldehyde (11) or 4-hydroxy-3-methoxybenzaldehyde (12)] under the same reaction conditions as for 9 affords the corresponding monocarbenium ion compound 14 (63% yield) [or 15 (43% yield) or 16 (77% yield)], respectively, each product of which is stabilized by 3-guaiazulenyl and dihydroxyphenyl (or hydroxymethoxyphenyl) groups. A facile preparation and crystal structures as well as spectroscopic, chemical, and electrochemical properties of 13-16, possessing two interesting resonance structures, respectively, i.e., a protonated o- (or p-) benzoquinonemethide form and a 3-guaiazulenylium ion form, in a solution of acetonitrile and further, in a single crystal, are reported. 相似文献
8.
Liu T Wang M Shi Z Cui H Dong W Chen J Akermark B Sun L 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(18):4474-4479
Complex [[(mu-SCH2)2N(4-NO2C6H4)]Fe2(CO)6] (4) was prepared by the reaction of the dianionic intermediate [(mu-S)2Fe2(CO)6](2-) and N,N-bis(chloromethyl)-4-nitroaniline as a biomimetic model of the active site of Fe-only hydrogenase. The reduction of 4 by Pd-C/H2 under a neutral condition afforded complex [[(mu-SCH2)2N(4-NH2C6H4)]Fe2(CO)6] (5) in 67 % yield. Both complexes were characterized by IR, 1H and 13C NMR spectroscopy and MS spectrometry. The molecular structure of 4, as determined by X-ray analysis, has a butterfly 2Fe2S core and the aryl group on the bridged-N atom slants to the Fe(2) site. Cyclic voltammograms of 4 and 5 were studied to evaluate their redox properties. It was found that complex 4 catalyzed electrochemical proton reduction in the presence of acetic acid. A plausible mechanism of the electrocatalytic proton reduction is discussed. 相似文献
9.
The reaction of [Pt2Me4(μ-SMe2)2] with ligands 4-C6H5C6H4CHNCH2CH2NMe2 (1a) and 2-C6H5C6H4CHNCH2CH2NMe2 (1b) carried out in acetone at room temperature produced compounds [PtMe2{4-C6H5C6H4CHNCH2CH2NMe2}] (2a) and [PtMe2{2-C6H5C6H4CHNCH2CH2NMe2}] (2b), respectively, in which the imines act as bidentate [N,N′] ligands. Cyclometallated [C,N,N′] compounds [PtMe{4-C6H5C6H3CHNCH2CH2NMe2}] (3a) and [PtMe{2-C6H5C6H3CHNCH2CH2NMe2}] (3b), were obtained by refluxing toluene solutions of compounds 2a or 2b. Reaction of [Pt2Me4(μ-SMe2)2] with ligands 4-C6H5C6H4CHNCH2Ph (1c) and 2-C6H5C6H4CHNCH2Ph (1d) produced compounds [PtMe{4-C6H5C6H3CHNCH2Ph}SMe2] (5c) and [PtMe{2-C6H5C6H3CHNCH2Ph}SMe2] (5d) containing a [C,N] ligand, from which triphenylphosphine derivatives 6c and 6d were also prepared. In all cases, metallation took place to yield five-membered endo-metallacycles and formation of seven-membered or of exo-metallacycles was not observed. The reactions of 3a, 3b, 6c and 6d with methyl iodide were studied in acetone and gave the corresponding cyclometallated platinum (IV) compounds. All compounds were characterised by NMR spectroscopy and compounds 3b, 4a, 6c and 6d were also characterised crystallographically. 相似文献
10.
A tris(N-pyrrolidinyl)phosphine (P(NC4H8)3) monosubstituted complex, [(μ-pdt)Fe2(CO)5P(NC4H8)3] (2) was synthesized as a functional model of the hydrogen-producing capability of the iron hydrogenase active site. The structure was fully characterized by X-ray crystallography. IR and electrochemical studies have indicated that the P(NC4H8)3 ligand has better electron-donating ability than that of those phosphine ligands, such as PMe3, PTA (1,3,5-triaza-7-phosphaadamantane), PMe2Ph PPh3, and P(OEt)3. The electrocatalytic activity of 2 was recorded in CH3CN in the absence and presence of weak acid, HOAc. The cathodic shift of potential at −1.98 V and the dependence of current on acid concentration have indicated that complex 2 can catalyze the reduction of protons to hydrogen at its Fe0FeI level in the presence of HOAc. IR spectroelectrochemical experiments are conducted during the reduction of 2 under nitrogen and carbon monoxide, respectively. The formation of a bridging CO group during the reduction of 2 at −1.98 V has been identified using IR spectroelectrochemical techniques, and an electrocatalytic mechanism of 2 consistent with the spectroscopic and electrochemical results is proposed. 相似文献
11.
Yu Chen WenChao Xu JunFeng Kou XuHui Wei BoLe Yu Hui Chao LiangNian Ji 《中国科学:化学(英文版)》2010,53(10):2099-2105
Three Ru(II) complexes [Ru(bpy)2(1-IQTNH)](ClO4)2 (1), [Ru(bpy)2(2-QTNH)](ClO4)2 (2) and [Ru(bpy)2(3-IQTNH)](ClO4)2 (3) (bpy = 2,2′-bipyridine, 1-IQTNH = 6-(isoquinolin-1-yl)-1,3,5-triazine- 2,4-diamine, 2-QTNH = 6-(quinolin-2-yl)-1,3,5-triazine- 2,4-diamine, 3-IQTNH = 6-(isoquinolin-3-yl)-1,3,5-triazine-2,4-diamine) have been synthesized and characterized by elemental analysis, 1H NMR spectroscopy, electrospray ionization mass spectrometry and X-ray crystallography. The electrochemical and spectroscopic properties of the complexes differ from those of [Ru(bpy)3]2+ owing to the structural differences between the ligands and their complexes. 相似文献
12.
《Journal of Coordination Chemistry》2012,65(7):1224-1237
Two new cobalt(II) complexes, [Co(L3)2]·CH3OH·CH3COCH3 (1) (HL3 = 1-(2-{[(E)-3,5-dichloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime) and Co(L4)2 (2) (HL4 = 1-(2-{[(E)-3,5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), have been synthesized via complexation of Co(II) acetate tetrahydrate with HL1 and HL2. HL1, HL2, and their corresponding Co(II) complexes were characterized by IR, 1H NMR spectra, as well as by elemental analysis and UV–Vis spectroscopy, respectively. The crystal structures of the complexes have been determined by single-crystal X-ray diffraction. 1 and 2 display that extensive hydrogen bonds and C–X···π bonding interactions construct the 1-D infinite chain [Co(L3)2]·CH3OH·CH3COCH3 and Co(L4)2 into 2-D supramolecular frameworks. The electrochemical properties of two Co(II) complexes were also investigated by cyclic voltammetry. 相似文献
13.
Reduction of trans-[OsL2(O)2] (1) (L-=[N(i-Pr2PS)2]-) with hydrazine hydrate afforded a dinitrogen complex 2, possibly "[OsL2(N2)(solv)]" (solv=H2O or THF), which reacted with RCN, R'NC, and SO2 to give trans-[OsL2(RCN)2] (R=Ph (3), 4-tolyl (4), 4-t-BuC6H4 (5)), trans-[OsL2(R'NC)2] (R'=2,6-Me2C6H3 (xyl) (6), t-Bu (7)), and [Os(L)2(SO2)(H2O)] (8) complexes, respectively. Protonation of compounds 2, 3, and 6 with HBF4 led to formation of dicationic trans-[Os(LH)2(N2)(H2O)][BF4]2 (9), trans-[Os(LH)2(PhCN)2][BF4]2 (10), and trans-[Os(LH)2(xylNC)2][BF4]2 (11), respectively. Treatment of 1 with phenylhydrazine and SnCl2 afforded trans-[OsL2(N2Ph)2] (12) and trans-[OsL2Cl2] (13), respectively. Air oxidation of compound 2 in hexane/MeOH gave the dimethoxy complex trans-[OsL2(OMe)2] (14), which in CH2Cl2 solution was readily air oxidized to 1. Compound 1 is capable of catalyzing aerobic oxidation of PPh3, possibly via an Os(IV) intermediate. The formal potentials for the Os-L complexes have been determined by cyclic voltammetry. The solid-state structures of compounds 4, 6, cis-8, 13, and 14 have been established by X-ray crystallography. 相似文献
14.
Synthesis of seven complexes containing oxazoline ([(L(1))(2)V=O] (4), [(L(1))(2)MoO(2)] (5), [(L(1))(2)UO(2)] (6); HL(1) (1) [HL(1) = 2-(4',4'-dimethyl-3'-4'-dihydroxazol-2'-yl)phenol]), chiral oxazoline ([(L(2))(2)UO(2)] (7); HL(2) (2) [HL(2) = (4'R)-2-(4'-ethyl-3'4'-dihyroxazol-2'-yl)phenol]), and oxazine ([(L(3))(2)V=O] (8), [(L(3))(2)Mn(CH(3)COO(-))] (9), [(L(3))(2)Co] (10); HL(3) (3) [HL(3) = 2-(5,6-dihydro-4H-1,3-oxazolinyl)phenol]) and their characterization by various techniques such as UV-vis, IR, and EPR spectroscopy, mass spectrometry, cyclic voltammetry, and elemental analysis are reported. The novel oxazine (3) and complexes 4, 5, 8 and 9 were also characterized by X-ray crystallography. Oxazine 3 crystallizes in the monoclinic system with the P2(1)/n space group, complexes 4 and 9 crystallize in the monoclinic system with the P2(1)/c space group, and complexes 5 and 8 crystallize in the orthorhombic system with the C222(1) space group and the P2(1)2(1)2(1) chiral space group, respectively. The representative synthetic procedure involves the reaction of metal acetate or acetylacetonate derivatives with corresponding ligand in ethanol. Addition of Mn(OAc)(2).4H(2)O to an ethanol solution of 3 gave the unexpected complex Mn(L(3))(2).(CH(3)COO(-)) (9) where the acetate group is coordinated with the metal center in a bidentate fashion. The catalytic activity of complexes 4-9 for oxidation of styrene with tert-butyl hydroperoxide was tested. In all cases, benzaldehyde formed exclusively as the oxidation product. 相似文献
15.
Maryam Hasanzadeh Mehdi Salehi Maciej Kubicki Seyyed Mohammad Shahcheragh Grzegorz Dutkiewicz Mikołaj Pyziak Ali Khaleghian 《Transition Metal Chemistry》2014,39(6):623-632
New complexes of cobalt(III) with the tridentate and tetradentate Schiff base ligands: 3-methoxy-2-{(Z)[(2-hydroxyphenyl)imino]methyl}phenol (H2L1), 4-[(2-hydroxyphenyl)imino]-2-pentanone (H2L2); and 2-((E)-1-(2-((E)-1-(2-hydroxy-4,5-dimethylphenyl)ethylideneamino)ethylimino)ethyl)-4,5 dimethylphenol (H2L3), namely [CoIII(L1)(N-MeIm)3]PF6 (1), [CoIII(L1)(py)3]ClO4 (2), [Co(L1)(py)3][Co(L1)2] (3) and [CoIII(L2)(N-MeIm)3]PF6 (4) and [Co(L3)(N-MeIm)2]PF6 (5), were synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structures of the complexes were determined by X-ray crystallography. In each of these complexes, the cobalt(III) centre has a slightly distorted octahedral environment, utilizing all available coordination centres of the ligands. The complexes were also screened for in vitro antibacterial activities against four human pathogenic bacteria, and their minimum inhibitory concentrations indicated good antibacterial activities. 相似文献
16.
《Comptes Rendus Chimie》2015,18(2):137-148
Cancer has become a leading cause of death worldwide, which is responsible for 7.6 million cancer deaths according to GLOBOCAN survey conducted in 2008. The exploration of cis-platin analogues (carboplatin, lobaplatin, nedaplatin, oxaliplatin) and their incorporation to the treatment of cancer patients has further led interest in exploring metal-based anticancer drugs. The current study describes the synthesis of two new tetra-coordinated mono- and tetranuclear organotin(IV) carboxylate complexes and their in vitro anticancer studies. Each one of the complexes (1–2) has been characterized by analytical (micro- and gravimetric analysis) and spectroscopic (FTIR, 1H, 13C, 119Sn-NMR) techniques. Furthermore, molecular structures of 1 and 2 were elucidated using X-ray crystallography. The characterization data showed that the coordination took place via oxygen atoms from the carboxylate anions to generate 1 as an organodistannoxane dimer and 2 as a mononuclear complex. Exceptionally, the NMR spectroscopic and X-ray crystallographic study showed that acetone molecules also took part in crystallizing 2. Both complexes were tested against three cancerous (colon cancer HCT 116, breast cancer MCF 7, leukemia K562) and one non-cancerous (3T3-L1) cell lines. Both complexes showed same IC50 value (0.2 μM) against HCT 116, whereas for the other two cancer cell lines (MCF 7 and K562) and a normal cell line (3T3-L1), 2 showed results better than 1. Importantly, the complexes showed exceptional activity against MCF 7 and K562 cell lines and the IC50 values were calculated in nanomoles (MCF 7, IC50s = 86.5 and 53.4 nM; K 562, IC50s = 22.9 and 49.6 nM for 1 and 2, respectively). Both, 1 and 2, showed IC50 values many times better than the standard drugs (5-FU, Tamoxifen, betulinic acid and cis-platin) used. Compared to cancerous cell lines, the complexes showed mild toxicity against normal cells (3T3-L1). Overall, two remained relatively effective. 相似文献
17.
The syntheses, characterization, crystal structures, and photophysical and electrochemical properties of two dinuclear and two polymeric Ag(I) complexes with three polypyridyl ligands, 2,3-di-2-pyridylquinoxaline (L(1)), 2,3-di-2-pyridyl-5,8-dimethoxyquinoxaline (L(2)), and 2,3,7,8-tetrakis(2-pyridyl)pyrazino[2,3-g] quinoxaline (L(3)), are described. The structures of the two boxlike dinuclear complexes with L(1) and L(2) and two chemically the same but differently crystallized one-dimensional zigzag chain coordination polymers also consisting of boxlike dinuclear subunits have been elucidated by X-ray analysis. [AgL(1)(CH(3)CN)](2)-(BF(4))(2).2CHCl(3) (1): monoclinic, C2/c; a = 28.631(2), b = 12.2259(11), c = 14.3058(12) A; beta = 99.180(2) degrees; Z = 4. [AgL(2)(CH(3)CN)(2)](2)(ClO(4))(2) (2): triclinic, P1; a = 12.3398(2), b = 13.750(2), c = 14.326(7) A; alpha = 83.494(3), beta = 74.631(3), gamma = 76.422(3) degrees; Z = 4. [[Ag(2)L(3)(NO(3))(2)].CH(3)CN](infinity) (3a): monoclinic, P2(1)/c; a = 9.5836(8), b = 13.4691(12), c = 14.0423(12) A; beta = 107.753(2) degrees; Z = 4. [Ag(2)L(3)()(NO(3))(2)](infinity) (3b): monoclinic, P2(1)/c; a = 8.4689(6), b = 16.0447(12), c = 11.7307(8) A; beta = 102.051(1) degrees; Z = 2. The structures of the dinuclear complexes 1 and 2 are similar to each other, with the two intramolecular Ag(I) centers of each complex being spanned by two ligands thus forming a unique boxlike cyclic dimer. In 1, each Ag(I) center is four-coordinated by three nitrogen atoms of two L(1) ligands and a CH(3)CN nitrogen donor, taking a distorted tetrahedral coordination geometry. The coordination environment of Ag(I) in 2 is similar to that in 1, except the formation of an additional weak coordination bond with the oxygen atom of the methoxy group of L(2). The structures of 3a,b are very similar to each other, except for the stacking patterns in the crystal lattices, and the cyclic boxlike dinuclear unit, which is similar to the structure of 1, constitutes the fundamental building block to form the one-dimensional zigzag chain structures due to the "end-on" nature of L(3). 1-3 exhibit metal-perturbed intraligand transitions in solution in 360-390 nm regions. Cyclic voltammetric studies of these complexes show the presence of reduction peak at approximately -0.5 V vs Fc(+/0). In the solid state at 77 K, they exhibit broad emission that may be assignable to originate from the metal-perturbed intraligand transitions. 相似文献
18.
《Journal of Coordination Chemistry》2012,65(15):2497-2510
Reactions of fresh M(OH)2 (M = Zn2+, Cd2+) precipitate and (RS)-2-methylglutaric acid (H2MGL), 2,2′-bipyridine (bipy), or 1,10-phenanthroline (phen) in aqueous solution at 50°C afforded four new metal–organic complexes [Zn2(bipy)2(H2O)2(MGL)2] (1), [Zn2(phen)2(H2O)(MGL)2] (2), [Cd(bipy)(H2O)(MGL)] · 3H2O (3), and [Cd(phen)(H2O)(MGL)] · 2H2O (4), which were characterized by single crystal X-ray diffraction, IR spectra, TG/DTA analysis as well as fluorescence spectra. In 1, the [Zn(bipy)(H2O)]2+ moieties are linked by R- and S-2-methylglutarate anions to build up the centrosymmetric dinuclear [Zn2(bipy)2(H2O)2(MGL)2] molecules. In 2, the 1-D ribbon-like chains [Zn2(phen)2(H2O)(MGL)2] n can be visualized as from centrosymmetric dinuclear [Zn2(phen)2(H2O)2(MGL)2] units sharing common aqua ligands. Both 3 and 4 exhibit 1-D chains resulting from [Cd(bipy)(H2O)]2+ and [Cd(phen)(H2O)]2+, respectively, bridged alternately by R- and S-2-methylglutarate anions in bis-chelating fashion. The intermolecular and interchain π···π stacking interactions form supramolecular assemblies in 1 and 1-D chains in 2–4 into 2-D layers. The hydrogen bonded lattice H2O molecules are sandwiched between 2-D layers in 3 and 4. Fluorescence spectra of 1–4 exhibit LLCT π → π* transitions. 相似文献
19.
Abedien Zabardasti Sayed Asad Shangaie 《Journal of the Iranian Chemical Society》2016,13(10):1875-1886
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
20.
Masato SasakiMasaru Nakamura Takayuki UriuHideko Takekuma Toshie MinematsuMasakuni Yoshihara Shin-ichi Takekuma 《Tetrahedron》2003,59(4):505-516
Reaction of guaiazulene (1) with p-dimethylaminobenzaldehyde in methanol in the presence of tetrafluoroboric acid gives the title monocarbocation compound, [4-(dimethylamino)phenyl]-3-guaiazulenylmethylium tetrafluoroborate (2), in 90% yield. The title investigations of compound 2 compared with those of two other monocarbocations stabilized by a 3-guaiazulenyl group (i.e. phenyl-3-guaiazulenylmethyl and [4-(isopropyl)phenyl]-3-guaiazulenylmethyl cations) are reported. 相似文献