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1.
Palladium–biscarbene complexes derived from N,N′-bis(1,2,4-triazol-1-yl)methane, which bear an alkyl chain functionalized with a hydroxyl group, have been synthesized ([Pd(L1)Br2] (6) and [Pd(L1)I2] (7) [L1 = 1,1′-(3-hydroxypropylidene)bis(4-butyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene)]). Each product is obtained as a non-equimolecular mixture of two conformers. The hydroxyl group has been replaced by bromide and methanesulphonate and ( [Pd(L2)Br2] [L2 = 1,1′-(3-bromopropylidene)bis(4-butyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene)] (9)) and ([Pd(L3)Br2] [L3 = 1,1′-(3-methanesulphonyloxypropylidene)-bis(4-butyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene)] (10)) were obtained, respectively, as mixtures of conformers. All compounds consist of a six-membered metallacyclic structure in a boat conformation. Major conformers present the functionalized chain in the axial position, while in minor conformers it is located in the equatorial position.  相似文献   

2.
The interaction between the zwitterionic buffers (3-[N-bis(2-hydroxyethyl)amino]-2-hydroxy propane sulfonic acid, N-(2-actamido)-2-aminoethane sulfonic acid, and 3-[(1,1-dimethyl-2-hydroxyethyl)amino]-2-hydroxy propane sulfonic acid) with some divalent transition metal ions (CuII, NiII, CoII, ZnII, and MnII) were studied at different temperatures (298.15 to 328.15) K at ionic strength I = 0.1 mol · dm−3 NaNO3 and in the presence of 10%, 30%, and 50% (w/w) dioxene by using potentiometry. The thermodynamic stability constants were calculated as well as the free energy change for the 1:1 binary complexation. The protonation constants of the zwitterionic buffers were also determined potentiometrically under the above conditions.  相似文献   

3.
The precursor [FeIII(L)Cl] (LH2 = N,N′-bis(2′-hydroxy-benzyliden)-1,6-diamino-3-azahexane) has been prepared and Mössbauer spectroscopy assigned a high-spin (S = 5/2) state at room temperature. The precursor is combined with the bridging units [SbV(X)6]? (X = CN?, NCS?) to yield star-shaped heptanuclear clusters [(LFeIII–X)6SbV]Cl5. The star-shaped compounds are in general high-spin systems at room temperature. On cooling to 20 K some of the iron(III) centers switch to the low-spin state as indicated by Mössbauer spectroscopy, i.e. multiple electronic transitions. While the cyano-bridged complex performs a multiple spin transition the thiocyanate-compound shows no significant population at both temperatures.  相似文献   

4.
《Polyhedron》2007,26(9-11):1773-1775
The spin density distribution of the paramagnetic [nBu4N]2[Cu(dana)] dana = N,N′-(naphthalene-2,3-diyl)-bis(oxamato) has been derived from angular dependent electron paramagnetic resonance measurements at room temperature. The results indicate a noticeable spin density transfer from the central metal to the coordinated N and O atoms. Quantum chemical studies using density functional theory reinforce the results.  相似文献   

5.
The coordination of heterocyclic thiourea ligands (L = N-(2-pyridyl)-N′-phenylthiourea (1), N-(2-pyridyl)-N′-methylthiourea (2), N-(3-pyridyl)-N′-phenylthiourea (3), N-(3-pyridyl)-N′-methylthiourea (4), N-(4-pyridyl)-N′-phenylthiourea (5), N-(2-pyrimidyl)-N′-phenylthiourea (6), N-(2-pyrimidyl)-N′-methylthiourea (7), N-(2-thiazolyl)-N′-methylthiourea (8), N-(2-benzothiazolyl)-N′-methylthiourea (9), N,N′-bis(2-pyridyl)thiourea (10) and N,N′-bis(3-pyridyl)thiourea (11)) with CuX (X = Cl, Br, I, NO3) has been investigated. CuX:L product stoichiometries of 1:1–1:5 were found, with 1:1 being most common. X-ray structures of four 3-coordinate mononuclear CuXL2 complexes (CuCl(6)2, CuCl(7)2, CuBr(6)2, and CuBr(9)2) are reported. In contrast, CuBr(1)2 is a 1D sulfur-bridged polymer. CuIL structures (L = 7, 8) are 1D chains with corner-sharing Cu2(μ-I)2 and Cu2(μ-S)2 units, and CuCl(10) is a 2D network having μ-Cl and N-/S-bridging L. Two [CuL2]NO3 structures are reported: a mononuclear 4-coordinate copper complex with chelating ligands (L = 10) and a 1D link-chain with N-/S-bridging L (L = 3). Two ligand oxidative cyclizations were encountered during crystallization. CuI crystallized with 6 to produce zigzag ladder polymer [(CuI)2(12)]·½CH3CN (12 = N-(pyrimidin-2-yl)benzo[d]thiazol-2-amine) and CuNO3 crystallized with 10 to form [Cu2(NO3)(13)2(MeCN)]NO3 (13 = dipyridyltetraazathiapentalene).  相似文献   

6.
Two substituted N-acylthioureas and the respective Ni(II) and Cu(II) complexes were synthesized, namely: N,N-di-n-butyl-N′-thenoylthiourea (Hnbtu); N,N-di-iso-butyl-N′-thenoylthiourea (Hibtu); bis[N,N-di-n-butyl-N′-thenoylthioureato]nickel(II), [Ni(nbtu)2]; bis[N,N-di-n-butyl-N′-thenoylthioureato]copper(II), [Cu(nbtu)2]; bis[N,N-di-iso-butyl-N′-thenoylthioureato]nickel(II), [Ni(ibtu)2]; bis[N,N-di-iso-butyl-N′-thenoylthioureato]copper(II), [Cu(ibtu)2]. The standard (p° = 0.1 MPa) molar enthalpies of formation and sublimation of the two N-acylthioureas were measured, at T = 298.15 K, by rotating-bomb combustion calorimetry and Calvet microcalorimetry, respectively. The standard (p° = 0.1 MPa) molar enthalpies of formation of the Ni(II) and Cu(II) complexes were determined, at T = 298.15 K, by high precision solution–reaction calorimetry. From the results obtained, the enthalpies of hypothetical metal–ligand and metal–metal exchange reactions, in the gaseous phase, were derived, thus allowing a discussion of the gaseous phase energetic difference between the complexation of Ni(II) and Cu(II) to 1,3-ligand systems with (S,O) ligator atoms.  相似文献   

7.
The complexes with long alkyl chains {[Fe(C16-trz)3](ClO4)2}n (1), [Fe(C15-BPT)2(NCS)2] (2), [Fe(C16-salen)Cl] (3), [Fe(C16-salmmen)Cl] (4), K[Fe(C16-salen)(CN)2] (5), K[Fe(C16-salmmen)(CN)2] (6), Na[Fe(C16-salmmen)(CN)2] (7), [Mn(C16-salen)Cl] (8), [Ni(C16-salen)] (9), [Cu(C16-salen)] (10) were synthesized (C16-trz = 4-hexadecyl-1,2,4-triazole, C15-BPT = N-(3,5-di-2-pyridinyl-4H-1,2,4-triazol-4-yl)-hexadecanecarboxamide, C16-salen = N,N-bis[4-(hexadecyloxy)salicylidene]ethylenediamine, C16-salmmen = N,N′-bis[4-(hexadecyloxy)salicylidene]-1,2-diaminopropane). Langmuir–Blodgett (LB) films of compounds 110 were prepared (Scheme 1). The transfers of the molecules from onto the gas–water surface to glass substrate were confirmed by UV–Vis spectra. The second harmonic generation (SHG) were estimated for the LB films formed by the metal complexes. The SHG was observed for the complexes with the long alkyl chains in LB film. The order of the intensity for the SHG related with the number of unpaired d electrons or the d electron configurations.  相似文献   

8.
F. Renz  St. Jung  M. Klein  M. Menzel  A.F. Thünemann 《Polyhedron》2009,28(9-10):1818-1821
The precursor [FeIII(L)Cl] (LH2 = N,N′-bis(2′-hydroxy-benzyliden)-1,6-diamino-3-N-hexane is a high-spin (S = 5/2) complex. This precursor is combined with the bridging units [SnIV(X)4] (X = CN?, NCS?) to yield star-shaped pentanuclear clusters, [(LFeIII–X)4Sn]Cl4. For X = CN? the 57Fe-Mössbauer data show a multiple spin transition between iron(III) in the high-spin and low-spin state, while the 119mSn-Mössbauer data indicate a valence tautomerism between Sn(IV) and Sn(II). Changing the bridging unit from X = CN? to X = NCS? turns the switchability off.  相似文献   

9.
The novel branched chain-type nitridosilicates Ce5Si3N9 and La5Si3N9 have been synthesized in a radio-frequency furnace starting from the respective metals and silicon diimide Si(NH)2 at 1625 °C for La5Si3N9 and 1650 °C for Ce5Si3N9, respectively. The structure of Ce5Si3N9 has been determined by single-crystal X-ray diffraction (Ce5Si3N9, Cmca (no. 64), a = 10.567(2) Å, b = 11.329(2) Å, c = 15.865(3) Å, V = 1899.3 Å3, Z = 8, R1 = 0.0391, 1480 independent reflections, 90 refined parameters). The structure of isotypic La5Si3N9 has been refined by the Rietveld method, starting from single-crystal data of Ce5Si3N9 (La5Si3N9, Cmca (no. 64), a = 10.647(4) Å, b = 11.414(4) Å, c = 16.030(5) Å, V = 1948.1 Å3, Z = 8, RP = 0.0348, RF2 = 0.0533). Both compounds are built up of alternating Q2- and Q3-type corner sharing SiN4 tetrahedra with additional corner sharing Q1-units attached to the Q3-tetrahedra pointing alternately in opposing directions. These zipper-like chains are intertwined in both directions perpendicular to the chain itself to form a three-dimensionally interlocked structure with the rare-earth ions situated between the chains. Magnetic measurements resulted in a ferromagnetic ground state with a magnetic moment in agreement with Ce3+.  相似文献   

10.
Interactions of dithioether ligands L2, L4 and L5 (L2 = 1,3-bis(4-(3-pyridyl) pyrimidin-2-ylthio) propane; L4 = 1,3-bis[4-(3-pyridyl) pyrimidinyl thiomethyl]benzene; L5 = 1,4-bis[4-(3-pyridyl)pyrimidinylthiomethyl] benzene) with Mn(II) ions and NH4SCN in an analogous way led to the formation of two discrete mononuclear complexes and a one-dimensional chain, respectively, which may be attributed to the different flexibility and positional isomerism of the ligands.  相似文献   

11.
《Tetrahedron: Asymmetry》2005,16(21):3520-3526
The [RuII(D4-Por1)(CO)(MeOH)] (D4-H2Por1 = tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanoanthracen-9-yl]porphyrin) complex 1 is an effective catalyst for asymmetric hydroxylation of aromatic hydrocarbons with 2,6-dichloropyridine N-oxide (Cl2pyNO) as terminal oxidant. Up to 76% ee was achieved for the catalytic hydroxylation of 4-ethyltoluene, 1,1-diethylindan and benzylcyclopropane. Both electron-donating and -withdrawing substituents were found to accelerate the catalytic oxidation reaction, and a large primary H/D kinetic isotope effect (kH/kD = 11 at 298 K) was observed for the catalytic ethylbenzene-d10 oxidation. A mechanism involving rate-limiting hydrogen atom abstraction by reactive oxoruthenium species is postulated.  相似文献   

12.
《Polyhedron》2007,26(9-11):2325-2329
The precursors [Fe(III)(5XL)Cl] (5XLH2 = N,N′-bis(1-hydroxy-2-benzyliden)-1,6-diamino-3-X-hexane, X = N,S) are high-spin (S = 5/2) complexes. This precursors are combined with the bridging unit [(NC)5Fe(II)-CN-Co(III)(CN)5]6− to yield star-shaped dodecanuclear clusters, [(5XLFe(III)-NC)5Fe(II)-CN-Co(III)(CN-Fe(III)5XL)5]Cl4. The star-shaped compounds are high-spin systems at room temperature. On cooling to 20 K some of the iron(III) centers in the N-star switch to the low-spin state as proven by Mössbauer spectroscopy, i.e. multiple electronic transitions, while the S-star remains in the high-spin state.  相似文献   

13.
《Comptes Rendus Chimie》2007,10(8):721-730
The cationic tetra-coordinated 16 electron complex [Ir(trop2dach)]+OTf (1) where (OTf = CF3SO3) and the neutral amine amido complex [Ir(trop2dach-1H)] (2) were isolated and structurally characterized. The NH function in 1 is easily deprotonated (pKaDMSO = 10.5) to yield the amino amido complex [Ir(trop2dach-1H)] (2), which is deprotonated at pKaDMSO = 19.6 to the anionic di(amido) iridate [Ir(trop2dach-2H)] (3); [(R,R)-top2dach stands for the tetrachelating diamino diolefin ligand (R,R)-N,N′-bis(5H-dibenzo[a,d]cyclohepten-5-yl)-1,2-diaminocyclohexane; (R,R)-top2dach-1H and (R,R)-top2dach-2H indicate the mono and double deprotonated form]. Complex 3 is easily oxidized by 1,4-benzoquinone (BQ) to the neutral iridium aminyl radical complex [Ir(trop2dach-2H)] (4). In combination with BQ as hydrogen acceptor and catalytic amounts of base, 4 serves as catalyst in the highly efficient dehydrogenation of functionalized primary alcohols to the corresponding aldehydes, RCH2OH + BQ  RCHO + H2BQ (H2BQ = catechol). Alcohols like geraniol and retinol are rapidly converted to geranial and retinal, while the conversion of sterically hindered alcohols like lavandulol is slower and the primary product, lavandulal, isomerizes to isolavandulal in a classical base-catalyzed reaction.  相似文献   

14.
3-(2-Chloroquinolin-3-yl)-1,5-bis(3,4,5-trimethoxy-phenyl)-pentane-2,4-dione derivatives 3a–b were conveniently synthesized in excellent yields (82% each) by tandem Knoevenagel condensation reactions of 2-chloro-3-carbaldehyde-quinoline 1ab with 3,4,5-trimethoxy acetophenone, followed by a base catalyzed Michael addition, such as DBU (1,8-diazabicyclo[5,4,0]undec-7-ene) with or without solvent. The reactions of 3a–b with Pd(dba)2 in the presence of PPh3 (1:2) in degassed acetone provided the dinuclear palladium complexes {Pd(C,N-2-C9H4N–CH–[–CH2CO(3,4,5-(OMe-)3–C6H2-]2–3-R-6)Cl(PPh3)}2 [(R = H (4a), R = OMe (4b)] in moderate yields (38% and 43%), which in turn reacted with an excess of isonitrile XyNC (Xy = 2,6-Me2C6H3) to give the corresponding palladacycles 5ab in moderate yields (45% and 43%). The palladacycles 5ab were also obtained in similar yields (32% and 33%) via a one-pot oxidative addition reaction of 3a-b with isonitrile XyNC:Pd(dba)2 (4:1). The products were characterized by satisfactory elemental analysis and spectral studies (IR, 1H, and 31P NMR). The crystal structure of 5a was determined by X-ray crystallography diffraction studies.  相似文献   

15.
The syntheses of two novel platinum(IV) complexes of formula [PtX2(S,S-eddp)]·nH2O (S,S-eddp = ethylenediamine-N,N′-di-S,S-2-propanoate ion, X = chlorido (1) or bromido (2), n = 4, 0) are reported. The complexes have been obtained by direct reaction of corresponding potassium hexahalogenidoplatinate(IV) with neutralized ethylenediamine-N,N′-di-S,S-2-propanoic acid (H2-S,S-eddp). The complexes were characterized by elemental analysis, infrared, 1H and 13C NMR spectroscopy. The spectroscopically predicted geometrical configurations of the obtained complexes were confirmed by X-ray analyses of the crystal structures of the s-cis-[Pt(S,S-eddp)Cl2]·4H2O and uns-cis-[Pt(S,S-eddp)Br2]. These complexes displayed significantly lower in vitro cytotoxicity in comparison to cisplatin.  相似文献   

16.
A cyclometalated iridium(III) complex containing 2-(9,9-diethylfluoren-2-yl)pyridine [Ir(Flpy)3] was prepared and used in the fabrication of both yellow and white organic light-emitting diodes (OLEDs). A hole-blocking material has been used as a hole barrier layer in-between different emission layers, helping the formation of the hole limitation region. With the proper position of a hole barrier layer and the construction of a four-emission-layer structure involving the use of [Ir(Flpy)3], the resulting WOLED shows sound device performance as well as very stable color even at high luminances. Such WOLEDs have been demonstrated to reveal superior white light color stability/efficiency trade-off optimization. The Commission Internationale de L’Eclairage (CIE) coordinate differences Δx and Δy are confined to ±0.015 when the luminance increases from 13 to 14806 cd/m2. The color rendering index (CRI) of the device is also very good, which varies only from 86 to 87 by changing from the normal direction to 80° off-normal at 12 V. The peak electrophosphorescence efficiency can reach as high as 24.6 cd/A at 168 cd/m2and it can still be kept at 17.2 cd/A at 10834 cd/m2. Such outstanding performance renders this all-phosphor WOLED very attractive as a white light source for illumination applications, which typically demand high efficiency, high CRI, and stable color in high brightness work conditions.  相似文献   

17.
《Polyhedron》2007,26(9-11):2330-2334
The precursors [Fe(III)(SYL)Cl] (SYLH2) = N,N′-bis(1-hydroxy-Y-2-benzyliden)-1,6-diamino-3-thiohexane, (Y = H, 3EtO, 5Me) are high-spin (S = 5/2) complexes. The precursors are combined with [Fe(II)(CN)6]4− and [Co(III)(CN)6]3− to yield star-shaped heptanuclear clusters, [Fe(II)(CN–Fe(III)SYL)6]Cl2 and [Co(III)(CN–Fe(III)SYL)6]Cl3. The star-shaped compounds are high-spin (HS) systems at room temperature. On cooling to 20 K some of the iron(III) centers perform some HS–HS transition.  相似文献   

18.
The single crystal analysis of the as-prepared 8,16-dimesityltetraceno[2,1,12,11-opqra]tetracene (DMTA) suggests that the parent bistetracene backbone is almost in a plane without any intermolecular p-stacking interaction. The fabricated devices based on DMTA as an emitter exhibit a maximum brightness of 632 cd/m2 at 14.7 V with the CIE coordinate of (0.623, 0.349).  相似文献   

19.
The preparation and magnetic properties of three Fe(II)–bis-Schiff base complexes, [Fe2(L1)2(4,4′-bpy)] · MeOH (1), [Fe(L2)(EtOH)] (2) and [Fe(L3)(MeOH)] (3) (L1 = N,N′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine; L2 = N,N′-bis(salicylidene)-1,2-phenylenediamine; L3 = N,N′-bis(5-Cl-salicylidene)-1,2-phenylenediamine; 4,4′-bpy = 4,4′-bipyridine) are reported. X-ray single crystal structure analyses for 13 reveal that 1 shows a dinuclear Fe(II)–bis-Schiff base complex bridged by 4,4′-bpy, while 2 and 3 show mononuclear structures. Molecular packing of 2 shows a uniform one-dimensional chain structure through hydrogen bonds and Fe?π interaction and that of 3 indicates significant π–π interaction to form a dimmer structure. The χTT plots of 13 show all ferromagnetic interaction at low temperature. The origin of the ferromagnetic interaction observed in 2 is tentatively ascribed to the dimer formation through Fe?π interaction at low temperature.  相似文献   

20.
The reaction of [Cp1CoI2]2 (1b) with 2 equiv of NaNCNH affords the 16-membered macrocyclic NCNH-bridged tetracobalt(III) complex [Cp1CoI(μ2-NCNH-N,N′)]4 (2b), while that with 2 equiv of Na2NCN yields the C3-elongated cubane-like NCN-bridged tetracobalt(III) complex [Cp1Co(μ3-NCN-N,N,N′)3(CoCp1)33-NCN-N,N,N)] (4b). Treatment of [Cp1RhCl2]2 (1c) with 2 equiv of NaNCNH gives the C3-elongated cubane-like tetrarhodium(III) complex [Cp1Rh(μ3-NCN-N,N,N′)3(RhCp1)33-NCN-N,N,N)] (4c) via the macrocyclic complex [Cp1RhCl(μ2-NCNH-N,N′)]4 (2c). On the other hand, the reaction of [Cp1CoCl]2 (7) with Na2NCN affords the anionic bis(NCN)-capped tricobalt(II) complex Na[(Cp1Co)33-NCN-N,N,N)2] (6). The molecular structures of complexes 2b · CH2Cl2 and 4c · 2C6H6 have been confirmed by X-ray analyses. The electrochemical properties of these types of NCN-bridged group 9 metal complexes have also been examined.  相似文献   

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