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1.
Jadwiga Szyd owska Adam Kr wczy ski Urszula Pietrasik Agnieszka Rogowska 《Liquid crystals》2005,32(5):651-658
Mesogenic tetradentate cis-enaminoketone Ni(II), Cu(II) and VO(II) complexes with rod-like and disc-like molecular shapes were synthesized. In these compounds some of the alkyl chains were perfluorinated. Replacing the alkyl chains by fluorinated chains stabilizes the columnar hexagonal Colh phase whereas lamellar phases are destroyed. 相似文献
2.
Duncan W. Bruce Bertrand Donnio Daniel Guillon Benoit Heinrich Mohammed Ibn-elhaj 《Liquid crystals》1995,19(4):537-539
Reaction of 3,4-dialkoxystilbazoles (n-3,4-OPhVPy) with silver dodecylsulphate (AgDOS) leads to complexes of the formula [Ag(n-3,4-OPhVPy)2][DOS]. These complexes are polycatenar liquid crystals and show mesophases which are characteristic of this structural type, namely, hexagonal, columnar and cubic. On cooling, some of the materials do not crystallize, but form stable glasses instead. All the mesophases have been fully characterized by small angle X-ray diffraction. 相似文献
3.
Steven M. Schultz Gerald Kehr Roland Fröhlich Gerhard Erker Nadia Kapernaum Constanze Hägele 《Liquid crystals》2013,40(8):919-926
A series of 2‐(4‐n‐alkylphenyl)indenes (3) with different alkyl substituents (CH3 to C10H21) were synthesized and systematically characterized using differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction compared with 2‐phenylindene (3a). Depending on the alkyl chain length, highly ordered crystal‐smectic E mesophases were observed and confirmed by X‐ray diffraction for the derivatives 3h–3k with heptyl to decyl chains (n = 6?9). For 3f with a pentyl side chain (n = 4), an X‐ray crystal structure analysis was carried out. 相似文献
4.
Joaquí n Barber Raquel Gim nez N lida Gimeno Mercedes Marcos Maria Del Carmen Pina Jos Luis Serrano 《Liquid crystals》2003,30(6):651-661
Copper and palladium complexes of new salicylaldimines derived from 3,4,5-tridecyloxyaniline, 2,3,4-tridecyloxyaniline and 4-decyloxyaniline have been synthesized and characterized. All the ligands bear four or more aliphatic chains with the aim of inducing columnar mesophases at low temperatures. In particular, metal complexes derived from 4-(3,4,5-tridecyloxybenzoyloxy)-salicyliden-3,4,5-tridecyloxyaninile display rectangular columnar mesophases at (or near) room temperature. These mesophase assignments have been confirmed by X-ray diffraction. A significant decrease of the melting points of the compounds is observed in the tridecyloxyaniline derivatives compared with those of similar complexes derived from mono- or di-decyloxyaniline. 相似文献
5.
Fuentealba M Garland MT Carrillo D Manzur C Hamon JR Saillard JY 《Dalton transactions (Cambridge, England : 2003)》2008,(1):77-86
The electronic communication between two redox centres through a Schiff base complex has been investigated in a series of ethylenediimine-bis(1-ferrocenyl-1,3-butanedionate) complexes of Zn(II) 1, Cu(II) 2, Ni(II) 3 and Co(II) 4. Cyclic voltammetry experiments of 1 and 2 exhibit a unique two-electron reversible oxidation wave, whereas in the case of 3 and 4 two and three one-electron oxidation processes are, respectively, observed. These results suggest some electronic interaction between the iron atoms of the ferrocenyl groups. DFT calculations carried out on model complexes show that for all the studied compounds the removal of the first two electrons corresponds to the oxidation processes of the iron centres in the weakly coupled ferrocenyl termini. The electronic communication between the two iron centres increases on going from 1 to 4. Finally, a re-indexation of the bands observed in the UV-Visible spectra has been carried out using TDDFT calculations. 相似文献
6.
Zn(II) and Mn(II) organometallic complexes I and II were first used to catalyze the cyanosilylation reaction, and good catalytic results (24–99 %) were achieved. The catalytic activity of the complexes was determined by 1H NMR. 相似文献
7.
JOAQUÍN BARBERA´ RAQUEL GIME´NEZ NE´LIDA GIMENO MERCEDES MARCOS MARIA DEL CARMEN PINA JOSE´ LUIS SERRANO 《Liquid crystals》2013,40(6):651-661
Copper and palladium complexes of new salicylaldimines derived from 3,4,5-tridecyloxyaniline, 2,3,4-tridecyloxyaniline and 4-decyloxyaniline have been synthesized and characterized. All the ligands bear four or more aliphatic chains with the aim of inducing columnar mesophases at low temperatures. In particular, metal complexes derived from 4-(3,4,5-tridecyloxybenzoyloxy)-salicyliden-3,4,5-tridecyloxyaninile display rectangular columnar mesophases at (or near) room temperature. These mesophase assignments have been confirmed by X-ray diffraction. A significant decrease of the melting points of the compounds is observed in the tridecyloxyaniline derivatives compared with those of similar complexes derived from mono- or di-decyloxyaniline. 相似文献
8.
M. Y. Tang J. Y. Liu W. Q. Chen Y. Yang S. Ren 《Russian Journal of Coordination Chemistry》2014,40(6):419-423
Two new cyano-bridged Cu(II)-Fe(II) binuclear complexes, [Cu(L1)Fe(CN)5(NO)] (I) [L1 = 1,3,6,8,11,14-hexaazatricyclo[12.2.1.18,11]octadecane and [Cu(L2)Fe(CN)5(NO)] · 2H2O (II) L2 = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.16,9]octadecane, have been assembled and structurally characterized by spectroscopy and X-ray crystallography. Complex I crystallizes in the monoclinic crystalline system of space group P21/c, while complex II crystallizes in the monoclinic crystalline system of space group P21/n. These two complexes assume a binuclear structure in which the Fe2+ ion is in an octahedron environment and the Cu2+ ion is in a square-prism geometry environment. 相似文献
9.
Edelsbacher Philipp Redhammer Gnther Monkowius Uwe 《Monatshefte für Chemie / Chemical Monthly》2020,151(4):543-547
Monatshefte für Chemie - Chemical Monthly - Four members of a new series of paddle-wheel copper(II) complexes bearing cyclobutanecarboxylate as bridging ligand with pyridine derived ligands in... 相似文献
10.
Tang JA Ellis BD Warren TH Hanna JV Macdonald CL Schurko RW 《Journal of the American Chemical Society》2007,129(43):13049-13065
Solid-state 63Cu and 65Cu NMR experiments have been conducted on a series of inorganic and organometallic copper(I) complexes possessing a variety of spherically asymmetric two-, three-, and four-coordinate Cu coordination environments. Variations in structure and symmetry, and corresponding changes in the electric field gradient (EFG) tensors, yield 63/65Cu quadrupolar coupling constants (CQ) ranging from 22.0 to 71.0 MHz for spherically asymmetric Cu sites. These large quadrupolar interactions result in spectra featuring quadrupolar-dominated central transition patterns with breadths ranging from 760 kHz to 6.7 MHz. Accordingly, Hahn-echo and/or QCPMG pulse sequences were applied in a frequency-stepped manner to rapidly acquire high S/N powder patterns. Significant copper chemical shielding anisotropies (CSAs) are also observed in some cases, ranging from 1000 to 1500 ppm. 31P CP/MAS NMR spectra for complexes featuring 63/65Cu-31P spin pairs exhibit residual dipolar coupling and are simulated to determine both the sign of CQ and the EFG tensor orientations relative to the Cu-P bond axes. X-ray crystallographic data and theoretical (Hartree-Fock and density functional theory) calculations of 63/65Cu EFG and CS tensors are utilized to examine the relationships between NMR interaction tensor parameters, the magnitudes and orientations of the principal components, and molecular structure and symmetry. 相似文献
11.
Kretz T Bats JW Losi S Wolf B Lerner HW Lang M Zanello P Wagner M 《Dalton transactions (Cambridge, England : 2003)》2006,(41):4914-4921
Cationic dinuclear Cu(II) complexes 3 and 4 have been prepared using the novel hydroquinone-based imine chelators 2,5-((i)Pr(2)NCH(2)CH(2)N[double bond, length as m-dash]CH)(2)-1,4-(OH)(2)-C(6)H(2) (1) and 2,5-(pyCH(2)CH(2)N[double bond, length as m-dash]CH)(2)-1,4-(OH)(2)-C(6)H(2) (2), respectively (py = 2-pyridyl). X-Ray quality crystals of both complexes were grown from their DMF solutions. The sterically more encumbered compound crystallizes in the form of discrete dinuclear entities with Cu(II) centres in a distorted square-planar ligand environment (one coordination site is occupied by a DMF molecule). The pyridyl derivative 4 features dinuclear hydroquinone-bridged subunits similar to 3. However, the Cu(II) ions are now six-coordinate with two DMF molecules at an axial and an equatorial position of a Jahn-Teller-distorted octahedron. Moreover, the dinuclear subunits are no longer isolated but linked with each other via bridging hydroquinone oxygen atoms which occupy the second apical position of each octahedron. The structure suggests that the magnetic properties of the resulting coordination polymer of 4 could be described by a model valid for dimerized spin chains. As a result of this analysis the antiferromagnetic coupling constants J(1)/k(B) = 9.9 K (intradimer) and J(2)/k(B) = 0.9 K (interdimer) are obtained. Both in 3 and in 4, the hydroquinone --> semiquinone transition of the central bridging unit (E degrees ' = + 0.57 V, 3; E degrees ' = + 0.51 V, 4; DMF; vs. SCE) displays features of chemical reversibility. In the case of , reduction of Cu(II) centres requires a peak potential of E(p) = - 0.42 V. 相似文献
12.
Susmita Mandal Ratan Sadhukhan Utpal Ghosh Soumik Mandal Manan Saha Ray J. Butcher 《Journal of Coordination Chemistry》2016,69(10):1618-1634
Reaction of Cu(II) nitrate with a new pyrazole-based Schiff base ligand, 5-methyl-3-formylpyrazole-N-(2′-methylphenoxy)methyleneimine (MPzOA), afforded two types of Cu(II) complexes at different reaction temperatures, [Cu(MPzOA)(NO3)]2 (1) and [Cu(3,7,11,15-tetramethylporphyrin)(H2O)](NO3)2 (2), reported together with a Ni(II) complex, [Ni(MPzOA)2(H2O)2]Br2 (3). The compounds are characterized by single crystal X-ray structure analyses along with several physico-chemical and spectral parameters. Complex 1 is authenticated as a bis(μ-pyrazolato)dicopper(II), while 2 is a porphyrinogen and 3 is a distorted octahedral complex. Structural analyses of the complexes reveal that 1 crystallized in monoclinic P21/n space group while 2 and 3 crystallized in monoclinic C2/c space group. DNA-binding studies of the complexes have shown that the complexes interact with CT-DNA. DNA-cleavage studies with plasmid DNA have shown that 1 and 2 induce extensive DNA cleavage in the presence of H2O2 as an additive, whereas there is no change in degradation of super-coiled DNA by 3 in the presence of additive. The antimicrobial studies of the complexes against Escherichia coli DH5α bacteria strain indicated that all the complexes were capable of killing E. coli with different LD50 values. 相似文献
13.
Michito Shiotsuka Takafumi Toda Kenta Matsubara Yuki Itou Takuto Hashimoto 《Transition Metal Chemistry》2013,38(8):913-922
A novel Pt(II) organometallic complex with 4-(4-ethynyl-phenylethynyl)-pyridine (DEBPy-H), namely [Pt(dppp)(DEBPy)2] (dppp = 1,3-bis-(diphenylphosphino)-propane), has been prepared by two synthetic routes. The DEBPy-H ligand was prepared by a shorter synthetic pathway and in higher yield than the method of previous reports. New Pt(II) organometallic complexes with DEBPy-H and four bidentate ligands [Pt(L–L)(DEBPy)2] (L–L = 1,2-bis-(diphenylphosphino)-benzene, bis-(dicyclohexyl)-ethane, 4,4′-dimethyl-2,2′-bipyridine, or 5,5′-dimethyl-2,2′-bipyridine) have also been prepared. These five Pt(II) complexes have two pyridyl units as an available coordination site that can operate as a metalloligand in nanoscale tectonics. A supramolecular complex of a tetranuclear metallocycle, [Pt(dppp)(DEBPy)2]2[Pt(dppp)]2(OTf)4, was synthesized from [Pt(dppp)(DEBPy)2] and [Pt(dppp)(OTf)2] as a corner connection through coordination-driven self-assembly. This supramolecular Pt(II) complex exists as a tetranuclear structure of the square type according to the interpretation of the ESI-mass and NMR spectra in solution. Five Pt(II) organometallics demonstrated the formation of similar tetranuclear metallocycles with [Pt(dppp)(OTf)2], as indicated by their ESI-mass and UV–vis spectra in solution. 相似文献
14.
A new series of binuclear copper(II) complexes were synthesised and studied by magnetic, spectral, ESR and cyclic voltammetry methods. The μeff values per copper atom correspond to the values observed for mononuclear copper(II) complexes. ESR spectral data in solution indicate weak interactions resulting from the electron delocalisation through the ligand system. Two nearly reversible red-ox couples are identified at 0.50 V and 0.75 V vs SCE. They correspond to Cu(II)αCu(III) red-ox processes, successively occurring at the two copper sites in the binuclear complexes. 相似文献
15.
The reactions of LiC6H4CH2NMe2 with MnI2 and CrCl2 in tetrahydrofuran gave the air-sensitive, paramagnetic complexes Li2(THF)2MX2(C6H4CH2NMe2)2. The solvated lithium halide may be removed from these complexes to give M(C6H4CH2NMe2)2 as paramagnetic organometallic complexes. Similarly the reactions of LiCH2C6H4NMe2 with CrCl2 and MnI2 gave M(CH2C6H4NMe2)2 whose magnetic moments and molecular weight measurements indicate that association occurs in solution. The X-ray crystal structure of Mn(CH2C6H4NMe2)2 was determined. The molecule is dimeric, containing one bridging and one terminal CH2C6H4NMe2 ligand per metal. The bridging ligand is bonded to both manganese atoms through a common CH2 group. One manganese atom has a bidentate CH2C6H4NMe2 ligand while the other manganese atom has a monodentate o-dimethylaminobenzyl ligand. 相似文献
16.
Verdejo B Blasco S García-España E Lloret F Gaviña P Soriano C Tatay S Jiménez HR Doménech A Latorre J 《Dalton transactions (Cambridge, England : 2003)》2007,(41):4726-4737
The dinuclear Cu2+ and Zn2+ as well as the mixed Cu2+-Zn2+ complexes of a 5,5'-pentaazaterpyridinophane ligand (L) are able to incorporate imidazolate (Im-) as a bridging ligand. The crystal structure of [Cu(2)L(Im)(Br)(H2O)](CF(3)SO(3))(2).3H2O (1) shows one copper coordinated by the three pyridine nitrogens of the terpyridine unit, one nitrogen of the imidazolate bridge (Im-) and one bromide anion occupying the axial position of a distorted square pyramid. The second copper atom is coordinated by the remaining imidazolate nitrogen, the three secondary nitrogens at the centre of the polyamine bridge and one water molecule that occupies the axial position. Magnetic measurements have been performed in the 2.0-300.0 K temperature range. Experimental data could be satisfactorily reproduced by using an isotropic exchange model H = -JS(1)S(2) with J = -52.3 cm(-1) and g = 2.09. Potentiometric studies have provided details of the speciation and stability constants for the mixed Cu2+-L-HIm, Zn2+-L-HIm (HIm = imidazole) and Cu2+-Zn2+-L-HIm systems. The apparent stability constant obtained at pH = 9 for the addition of imidazole to the dinuclear Cu2+ complexes is one of the highest so far reported (log K = 7.5). UV-Vis spectroscopy and paramagnetic NMR data show that imidazole coordinates to the Cu2+ ions as a bridging imidazolate ligand from pH 5 to 10. Electrochemical reduction of the Cu2+-Zn2+-L complex occurs in two successive one-electron per copper ion quasi-reversible steps. The formal potential of the Cu2+-Zn2+-L/Cu+-Zn2+-L couple is close to that of SOD. The IC50 values measured at pH 7.8 by means of the nitro blue tetrazolium method show significant SOD activity for the dinuclear Cu2+ complexes (IC50 = 2.5 microM) and moderate activity for the Cu2+-Zn2+ mixed systems (IC50 = 30 microM). 相似文献
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19.
《Journal of organometallic chemistry》1990,395(2):C35-C38
The reactions of K[HB(pz)3] (pz = pyrazol-1-yl) with the coordinatively unsaturated σ-vinyl complexes [Ru(CRCHR)Cl(CO)(PPh3)2] (R = H, Me, C6H5) proceed with loss of a chloride and a phosphine ligand to provide the compounds [Ru(CRCHR)(CO)(PPh3){HB(pz)3}] in high yield. Similar treatment of the complex [Ru(C6H4Me-4)Cl(CO)(PPh3)2] leads to the related σ-aryl derivative [Ru(C6H4Me-4)(CO)(PPh3){HB(pz)3}] whilst the complex [RuClH(CO)(PPh3)3] treated successively with diphenylbutadiyne and K[HB(pz)3] provides the unusual derivative [Ru{C(CCPh)CHPh}(CO)(PPh3){HB(pz)3}]. 相似文献
20.
Chen J Russo R Chao W Margerum LD Malachowski MR White R Thawley Z Thayer A Rheingold AL Zakharov LN 《Dalton transactions (Cambridge, England : 2003)》2007,(24):2571-2579
A series of biphenyl-based N(3)O ligands, 2, 4, 6, and 8 were synthesized and their Cu(II) complexes prepared. These complexes were characterized by a combination of elemental analysis, FAB-MS, UV-vis spectroscopy and electrochemistry. The structure of [Cu(N(3)O-mpy-NO2)Cl2], 12 [N(3)O-mpy = 2-(3-pyridylmethylimino)-2'-(2-methylaminophenol)biphenyl], was solved and showed that the ligand coordinates through the three nitrogens with the phenol oxygen uncoordinated. Titration of azide anion into solutions of the complexes in methanol resulted in the appearance of a new band between 485-495 nm at the expense of the starting peak at 380 nm. Cyclic voltammetry studies indicated that the complexes undergo quasi-reversible one-electron reductions in acetonitrile at potentials between 0.13-0.58 V vs. Ag/AgCl. The complexes were found to be weakly active for the oxidation of di-tert-butyl catechol (DTBC). 相似文献