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Nicolas Bréfuel Isabelle Vang Sergiu Shova Françoise Dahan Jean-Pierre Costes Jean-Pierre Tuchagues 《Polyhedron》2007
The synthesis and characterization of new symmetrical FeII complexes, [FeLA(NCS)2] (1), and [FeLBx(NCS)2] (2–4), are reported (LA is the tetradentate Schiff base N,N′-bis(1-pyridin-2-ylethylidene)-2,2-dimethylpropane-1,3-diamine, and LBx stands for the family of tetradentate Schiff bases N,N′-bis[(2-R-1H-imidazol-4-yl)methylene]-2,2-dimethylpropane-1,3-diamine, with: R = H for LB1 in 2, R = Me for LB2 in 3, and R = Ph for LB3 in 4). Single-crystal X-ray structures have been determined for 1 (low-spin state at 293 K), 2 (high-spin (HS) state at 200 K), and 3 (HS state at 180 K). These complexes remain in the same spin-state over the whole temperature range [80–400 K]. The dissymmetrical tetradentate Schiff base ligands LCx, N-[(2-R2-1H-imidazol-4-yl)methylene]-N′-(1-pyridin-2-ylethylidene)-2,2-R1-propane-1,3-diamine (R1 = H, Me; R2 = H, Me, Ph), containing both pyridine and imidazole rings were obtained as their [FeLCx(NCS)2] complexes, 5–10, through reaction of the isolated aminal type ligands 2-methyl-2-pyridin-2-ylhexahydropyrimidine (R1 = H, 5–7) or 2,5,5-trimethyl-2-pyridin-2-ylhexahydropyrimidine (R1 = Me, 8–10) with imidazole-4-carboxaldehyde (R2 = H: 5, 8), 2-methylimidazole-4-carboxaldehyde (R2 = Me: 6, 9), and 2-phenyl-imidazole-4-carboxaldehyde (R2 = Ph: 7, 10) in the presence of iron(II) thiocyanate. Together with the single-crystal X-ray structures of 7 and 9, variable-temperature magnetic susceptibility and Mössbauer studies of 5–10 showed that it is possible to tune the spin crossover properties in the [FeLCx(NCS)2] series by changing the 2-imidazole and/or C2-propylene susbtituent of LCx. 相似文献
3.
Two neutral ligands, L1 · 2H2O and L2 · H2O, and seven complexes, [Cu(pmb)2(L1)] (1), [Cu(pmb)2(L2)] (2), [Cu(Ac)2(L2)] · 4H2O (3), [Cu(4-aba)2(L2)] (4), [Ag(4-ts)(L1)(H2O)] (5), [Ag2(epes)2(L1)] · 2H2O (6), [Ag(1,5-nds)0.5(L2)] · 0.5C2H5OH · H2O (7) [where L1 = 1,1′-(1,4-butanediyl)bis(2-methylbenzimidazole); L2 = 1,1′-(1,4-butanediyl)bis(2-ethylbenzimidazole), pmb = p-methoxybenzoate anion; Ac = acetate anion; 4-aba = 4-aminobenzoate anion; 4-ts = p-toluenesulfonate anion; epes = N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonate) anion; 1,5-nds = 1,5-naphthalenedisulfonate anion], have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The L1 and L2 ligands in compounds 1–7 act as bridging ligands, linking metal ions into chain structures. The chains in compounds 3, 4 and 6 interlace with each other by hydrogen bonds to generate 3D supramolecular structures. In compound 5, π–π interactions between adjacent L1 ligands hold the chains to a supramolecular layer. In compound 7, the sulfonate anions act as counterions in the framework. The thermal stabilities of 3, 6 and 7, and the luminescent properties for 5–7 in the solid states are also discussed. 相似文献
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5.
The reactions of Cu(ClO4)2·6H2O with 6-(benzylamino)purine derivatives in a stoichiometric 1:2 metal-to-ligand ratio led to the formation of penta-coordinated dinuclear complexes of the formula [Cu2(μ-L1–8)4(ClO4)2](ClO4)2·nsolv, where L1 = 6-(2-fluorobenzylamino)purine (complex 1), L2 = 6-(3-fluorobenzylamino)purine (2), L3 = 6-(4-fluorobenzylamino)purine (3), L4 = 6-(2-chlorobenzylamino)purine (4), L5 = 6-(3-chlorobenzylamino)purine (5), L6 = 6-(4-chlorobenzylamino)purine (6), L7 = 6-(3-methoxybenzylamino)purine (7) and L8 = 6-(4-methoxybenzylamino)purine (8); n = 0–4 and solv = H2O, EtOH or MeOH. All the complexes have been fully characterized by elemental analysis, FTIR, UV–Vis and EPR spectroscopy, and by magnetic and conductivity measurements. Variable temperature (80–300 K) magnetic susceptibility data of 1–8 showed the presence of a strong antiferromagnetic exchange interaction between two Cu(II) (S = 1/2) atoms with J ranging from −150.0(1) to −160.3(2) cm−1. The compound 6·4EtOH·H2O was structurally characterized by single crystal X-ray analysis. The Cu?Cu separation has been found to be 2.9092(8) Å. The antiradical activity of the prepared compounds was tested by in vitro SOD-mimic assay with IC50 in the range 8.67–41.45 μM. The results of an in vivo antidiabetic activity assay were inconclusive and the glycaemia in pre-treated animals did not differ significantly from the positive control. 相似文献
6.
A series of mixed ligand cadmium(II) complexes having 3,5-dimethylpyrazole and aromatic carboxylate are structurally characterized. The effect of substituent on aromatic ring and also the effect of composition on co-ordination behavior of these complexes are ascertained. Hydrogen bonded self-assembled mononuclear complexes are obtained from composition [Cd(L)2(La)2] where La = 3,5-dimethylpyrazole L = R–C6H4COO– [R = H (1), 2-Cl (2), 4-OH (3), 2-OH (4)]. The cadmium complex (5) having composition [Cd(L)2(La)(H2O)] (L = 2-NO2–C6H4COO–) is tetra-nuclear. The complex has eight and six co-ordination around cadmium and self-assembles through hydrogen bonding leading to form extended chain structure. The four complexes (1–4) have six co-ordinated trigonal prismatic geometry around cadmium ions. Cadmium complexes having composition [Cd(L)2(La)] such as R = 4-NO2 (6), 4-Cl (7), and 1-naphthoate complex (8) are co-ordination polymers with seven co-ordination geometry around cadmium. In these co-ordination polymers different Cd–Cd distances are observed for alternate pair of cadmium ions. For example in the case of the co-ordination polymer of 4-nitro-benzoate complex the Cd–Cd distance between alternate pairs are 4.138 Å, and 3.748 Å. The 1-naphthoate complex having pyridine has composition [Cd(L)2(Lb)2](H2O)] (9) where Lb = pyridine and L = 1-naphthoate has seven co-ordination with a distorted pentagonal bipyramid geometry. 相似文献
7.
Chiral and achiral p-tert-butyl-calix[4]arene bisphosphites (L1–L3) have been synthesized by the reaction of p-tert-butyl-calix[4]arene and the phosphorodichloridites, ROPCl2 [R = (1S,2R,5R)-(+)-iso-menthyl (L1), (1R,2S,5R)-(−)-menthyl (L2) or C6H4But-4 (L3)]. These bisphosphites function as chelating ligands in palladium(II) and platinum(II) complexes which are formed in good yields by the reaction of PdCl2(PhCN)2, MCl2(COD) (M = Pd or Pt) or PdMeCl(COD) with the respective calix[4]arene bisphosphite. Single crystal X-ray diffraction studies performed on the complexes [PdCl2(L1)], [PdCl2(L2)], [PdCl2(L3)] and [PtCl2(L3)] reveal a near square planar geometry around the metal with the two chloride ligands in a cis disposition. The crystal packing in the complexes [PdCl2(L1)] and [PdCl2(L2)], which crystallize in the chiral (P6122) space group, shows different hydrophobic channels with intermolecular C–H?Cl hydrogen bonding. The complexes [PdCl2(L3)] and [PtCl2(L3)] are isostructural and the molecules in the crystal lattice are linked by intermolecular C–H?Cl and C–H?O hydrogen bonds. 相似文献
8.
Dipanwita Das 《Journal of organometallic chemistry》2010,695(7):955-2564
1-(Phenylselenomethyl)-1H-benzotriazole (L1) and 1-(4-methoxyphenyltelluromethyl)-1H-benzotriazole (L2) have been synthesized by reacting 1-(chloromethyl)-1H-benzotriazole with in situ generated nucleophiles PhSe− and ArTe−, respectively. The complexes of L1 and L2 with Pd(II) and Ru(II)(η6-p-cymene) have been synthesized. Proton, carbon-13, Se-77 and/or Te-125 NMR spectra authenticate both the ligands and their complexes. The single crystal structures of L1, L2 and [RuCl(η6-p-cymene)(L)][PF6] (L = L1: 3, L = L2: 4) have been solved. The Ru-Se and Ru-Te bond lengths have been found 2.4801(11) and 2.6183(10) Å, respectively. The palladium complexes, [PdCl2(L)] (L = L1: 1, L = L2: 2) have been explored for Heck and Suzuki-Miyaura C-C coupling reactions. The TON values are upto 95,000. The Ru-complexes have been found promising for catalytic oxidation of alcohols (TON ∼ 7.8-9.4 × 104). The complexes of telluroether ligands are as efficient catalysts as those of selenoether ones and in fact better for catalytic oxidation. 相似文献
9.
Two mononuclear and one dinuclear copper(II) complexes, containing neutral tetradentate NSSN type ligands, of formulation [CuII(L1)Cl]ClO4 (1), [CuII(L2)Cl]ClO4 (2) and [CuII2(L3)2Cl2](ClO4)2 (3) were synthesized and isolated in pure form [where L1 = 1,2-bis(2-pyridylmethylthio)ethane, L2 = 1,3-bis(2-pyridylmethylthio)propane and L3 = 1,4-bis(2-pyridylmethylthio)butane]. All these green colored copper(II) complexes were characterized by physicochemical and spectroscopic methods. The dinuclear copper(II) complex 3 changed to a colorless dinuclear copper(I) species of formula [CuI2(L3)2](ClO4)2,0.5H2O (4) in dimethylformamide even in the presence of air at ambient temperature, while complexes 1 and 2 showed no change under similar conditions. The solid-state structures of complexes 1, 2 and 4 were established by X-ray crystallography. The geometry about the copper in complexes 1 and 2 is trigonal bipyramidal whereas the coordination environment about the copper(I) in dinuclear complex 4 is distorted tetrahedral. 相似文献
10.
Sumanta Kumar Padhi Dipankar Saha Rojalin Sahu Japyesan Subramanian Vadivelu Manivannan 《Polyhedron》2008
Three complexes of composition [CrL(X)3], where L = 4′-(2-pyridyl)-2,2′:6′,2″-terpyridine and X = Cl−, N3−, NCS− are synthesized. They are characterized by IR, UV–Vis, fluorescence, EPR spectroscopic, and X-ray crystallographic studies. Structural studies reveal that the Cr(III) ion is coordinated by three N atoms of L in a meridional fashion. The three anions occupy the other three coordination sites completing the mer-N3Cl3 (1) and mer-N3N3 (2 and 3), distorted octahedral geometry. The Cr–N2 has a shorter length than the Cr–N1 and Cr–N3 distances and the order Cr–N(NCS−) < Cr–N(N3−) < Cr–Cl is observed. They exhibit some of the d–d transitions in the visible and intra-ligand transitions in the UV regions. The lowest energy d–d transition follows the trend [CrLCl3] < [CrL(N3)3] < [CrL(NCS)3] consistent with the spectrochemical series. In DMF, they exhibit fluorescence having π → π∗ character. All the complexes show a rhombic splitting as well as zero-field splitting (zfs) in X-band EPR spectra at 77 K. 相似文献
11.
The reactions of the polydentate ligand 1,4-bis(4,5-dihydro-2-oxazolyl)benzene (L) with AgX (X = CH3COO−, ClO4− and CF3SO3−) afforded the complexes [Ag2(L)(CH3COO)2]∞ (1), [Ag2(L)3(ClO4)2]∞ (2), and [Ag(L)(CF3SO3)]∞ (3), whereas the reaction of L with Ag2SO4 in MeOH/H2O system afforded {[Ag2(L)3(H2O)3][SO4] · 9H2O}∞ (4). The EA and IR have been recorded and all the complexes have been structurally characterized by X-ray crystallography, confirming that complexes 1–4 are two-dimensional coordination polymeric frameworks. The bidentate L ligands in complexes 3 and 4 adopt both the syn and anti conformation and those in 1 and 2 adopt the anti conformation only. The anions CH3CO2− in complex 1 bridge the Ag(I) atoms in η1, η2, μ3-coordination mode forming a 1-D zig-zag –[Ag(CH3COO)]n– chains, while the anions ClO4−, CF3SO3− and SO42− in complexes 2–4 are not coordinated to the Ag(I) atoms, but all of them play an important roles in linking cationic 2-D frameworks into 3-D supramolecular structures. 相似文献
12.
Structural diversity in the self-assembly of Ag(I) complexes containing 2-amino-5-halopyrimidine 总被引:1,自引:0,他引:1
Chia-Jun WuChih-Yuan Lin Pei-Chi ChengChun-Wei Yeh Jhy-Der Chen Ju-Chun Wang 《Polyhedron》2011,30(13):2260-2267
A series of Ag(I) complexes containing the 2-amino-5-halopyrimidine ligands have been synthesized and their structures characterized by X-ray crystallography. The isomorphous complexes Ag(L-Cl)2(CF3SO3) (L-Cl = 2-amino-5-chloropyrimidine), 1, and Ag(L-Br)2(CF3SO3) (L-Br = 2-amino-5-bromopyrimidine), 2, are mononuclear, while [Ag(L-Br)(CF3SO3)]6·6C4H10O, 3, and [Ag(L-I)(CF3SO3)]6 (L-I = 2-amino-5-iodopyrimidine), 4, show cyclic self-assembly of six Ag(Ι) atoms and six L-X ligands, resulting in 24-membered metallocycles. The complex [Ag(L-I)(CF3SO3)]∞, 5, forms 1D zigzag chains which are linked through C-I?Ag and Ag?O interactions to form a 3D structure. The tetranuclear complexes [Ag(L-X)(NO3)]4 [X = Cl, 6; Br, 7] form 16-membered metallocycles, while [Ag(L-X)(ClO4)]∞ [X = Cl, 8; Br, 9] exhibit helical chains. The different structure of 5 from 1 and 2 appears to be due to the stronger nucleophilic character of the iodine atom. In these complexes, the relatively smaller NO3− anions lead to the formation of tetranuclear metallocycles and the larger CF3SO3− anions support the hexanuclear metallocycles, whereas the ClO4− anions induce the helical chains. 相似文献
13.
José Luis Serrano Luis García José Pérez Eduardo Pérez Joaquín García Gregorio Sánchez Gregorio López Ian J.S. Fairlamb Malva Liu 《Polyhedron》2008
The dinuclear hydroxo complex [{Pd(μ-OH)(Phox)}2] (I) (Phox = 2-(2-oxazolinyl)phenyl) reacts in a 1:2 molar ratio with several imidate ligands to yield new cyclometallated palladium complexes [{Pd(μ-NCO)(Phox)}2] containing asymmetric imidate –NCO– bridging units. [–NCO– = succinimidate (succ) (1), phtalimidate (phtal) (2), maleimidate (mal) (3), 2,3-dibromomaleimidate (2,3-diBrmal) (4) and glutarimidate (glut) (5)]. The reaction of these complexes with tertiary phosphines provides novel mononuclear N-bonded imidate derivatives of the general formula [Pd(imidate)(Phox)(PR3)] [R = Ph (a), 4-F–C6H4 (b) or CH2CH2CN (c)]. The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, FAB, 1H, 13C and 31P). The single-crystal structures of compounds 4, 4a and 5a have been established. 相似文献
14.
Two new copper(II) complexes with aminothioether ligands, [Cu(L1)(ClO4)](ClO4) · 0.5H2O (1) and [Cu(L2)(H2O)](ClO4)2 · H2O (2) (L1 = 2-benzyl-1,3-bis(aminoethylthio)propane and L2 = 2-(4-butylbenzyl)-1,3-bis(aminoethylthio)propane), have been synthesized and characterized. The single crystal X-ray diffraction analysis reveals that both 1 and 2 adopt distorted square pyramidal geometries. The binding modes of both complexes with calf thymus DNA were investigated by UV–Vis and CD spectroscopies. The results show that both complexes mainly adopt an electrostatic attraction binding mode with DNA and the binding constants are (1.62 ± 0.02) × 103 and (2.02 ± 0.02) × 103 M−1, respectively. Both complexes are able to cleave pBR322 plasmid DNA efficiently in the presence of ascorbic acid and the activity of 2 is higher than that of 1. The DNA cleavage by 1 and 2 were inhibited strongly in the presence of DMSO and tert-butyl alcohol, which suggests that hydroxyl radicals are the reactive oxygen species for the cleavage. 相似文献
15.
The platinum(II) complex [PtMe2(bpy)] (bpy = 2,2′-bipyridine) reacted with a large excess of dihaloalkanes X(CH2)nX (n = 1, X = Cl; n = 4, X = Br) to form the platinum(IV) complexes [PtMe2X{(CH2)nX}(bpy)] (n = 1, X = Cl, 1a; n = 4, X = Br, 1b). The reaction of complexes 1a and 1b with SnBr2 resulted in insertion of SnBr2 into Pt–X (X = Cl, Br) bond to afford the trihalostannyl complexes [PtMe2(SnBr2X){(CH2)nX}(bpy)] (n = 1, X = Cl, 2a; n = 4, X = Br, 2b). The synthesis of such trihalostannylplatinum(IV) complexes is reported for the first time. The complex 2a was decomposed in CH2Cl2 solution and single crystals of [PtBr2(bpy)] (3a) were obtained. The X-ray structure determination of 3a revealed a new polymorphic form of [PtBr2(bpy)]. The molecules undergo a remarkable stacking along the b-axis to form a zigzag Pt?Pt?Pt chain containing both short (3.799 Å) and long (5.175 Å) Pt?Pt separations through the crystal. The crystal structure is compared to that of the yellow modification of [PtBr2(bpy)]. 相似文献
16.
Fatima Zohra Chiboub Fellah Jean-Pierre Costes Carine Duhayon Jean-Claude Daran Jean-Pierre Tuchagues 《Polyhedron》2010
The synthesis of two mononuclear precursor copper complexes, [(HL2)2Cu], 1, and [(HL3)2Cu]·H2O, 2, and three dinuclear Cu–Ln complexes, [(HL1)2Cu(CH3CN)2Gd(NO3)3], 3, [(HL3)2CuGd(NO3)3]·2(H2O), 4, and [(HL3)2CuTb(NO3)3]·2(H2O), 5, based on the ligands H2L1 (4-bromo-2-[1-(5-bromo-2-hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol), H2L2 (2-(1H-benzimidazol-2-yl)-4-bromo-6-methoxyphenol) and H2L3 (2-(1H-benzimidazol-2-yl)-6-methoxyphenol) are described in this contribution. The X-ray crystal structures of H2L2, 1, 3, 4, and 5 have been solved. The novel ligand H2L2 crystallizes with two independent molecules in the asymmetric unit; several intermolecular hydrogen contacts connect alternate independent H2L2 molecules into chains developing along c. In complex 1, two (HL2)− ligands chelate the copper ion through their imidazolyl nitrogen and phenoxo oxygen atoms, in a relative head to tail arrangement. The molecular structure of 3 is similar to those of the previously reported Cu–Ln complexes of H2L1. In the isostructural complexes 4 and 5, two HL3 ligands sandwich one Cu2+ ion through their N,O sites and one Ln3+ ion through their O2 site, implying a relative head to head arrangement, at variance with the relative head to tail arrangement of HL2 in the mononuclear copper precursor 1. The magnetic properties of 1, 3, 4, and 5 have been investigated. Extended intermolecular antiferromagnetic interactions operate in complex 1 ((JChain = −0.8(1) cm−1). Ferromagnetic interactions between Gd (S = 7/2) and Cu (S = 1/2) centers operate in complexes 3 and 4, leading to an S = 4 ground state (JCuGd = 7.2(2) cm−1 for 3 and JCuGd = 6.5(2) cm−1 for 4). Depopulation of the Tb Stark levels, preclude obtaining reliable information on the presence and sign of the Cu–Tb interaction in 5. These new complexes are complementary to those previously reported: the Cu–O2–Gd core is planar while deformations are borne by the ligands at variance with previous examples where the constraints were located at the Cu–O2–Gd core. The presence of two independent ligands in the Cu,Gd coordination spheres confers a degree of freedom greater than that allowed by a unique tetradentate ligand. As a result, the strength of the magnetic interaction is not solely related to the dihedral angle between the CuOO and GdOO planes in the central core. 相似文献
17.
Shota Niibayashi 《Journal of organometallic chemistry》2005,690(2):276-285
A series of titanocene(III) alkoxides L2Ti(III)OR where L = Cp, R = Et(1b), tBu(1a), 2,6-Me2C6H3(1c), 2,6-tBu2-4-Me-C6H2(1d), or L = Cp*, R = Me(2e), tBu(2a), Ph(2f) was synthesized and subjected to reaction with [CpM(CO)3]2 [M = Mo, W], [CpRu(CO)2]2, and Co2(CO)8. The Ti(III) precursors 1a, 1c, 2a, 2e, and 2f reacted with [CpM(CO)3]2 [M = Mo, W] to form heterobimetallic complexes L2Ti(OR)(μ-OC)(CO)2MCp [M = Mo, W], of which Ti and M are linked by an isocarbonyl bridge. Reactions of these Ti(III) complexes with Co2(CO)8 resulted in formation of Ti-Co1 heterobimetallic complexes, from 2a, 2e, or 2f, or Ti-Co3 tetrametallic complexes, Cp2Ti(OtBu)(μ-OC)Co3(CO)9 from 1a, 1b, or 1c. The products were characterized by NMR, IR, and X-ray crystallography. Reaction mechanisms were proposed from these results, in particular, from steric/electronic effects of titanium alkoxides. 相似文献
18.
Ta-Pin Tsai Yen-Tsang Huang Umasankar Ray Yin-Jui Chang Pei-Chi Cheng Chia-Jun Wu Jhy-Der Chen Ju-Chun Wang 《Polyhedron》2010
The syntheses and structures of a series of metal complexes, namely Cu2Cl4(L1)(DMSO)2·2DMSO (L1 = N,N′-bis(2-pyridinyl)-1,4-benzenedicarboxamide), 1; {[Cu(L2)1.5(DMF)2][ClO4]2·3DMF}∞ (L2 = N,N′-bis(3-pyridinyl)-1,4-benzenedicarboxamide), 2; {[Cd(NO3)2(L3)]·2DMF}∞ (L3 = N,N′-bis-(2-pyrimidinyl)-1,4-benzenedicarboxamide), 3; {[HgBr2(L3)]·H2O}∞, 4, and {[Na(L3)2][Hg2X5]·2DMF}∞ (X = Br, 5; I, 6) are reported. All the complexes have been characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. Complex 1 is dinuclear and the molecules are interlinked through S?S interactions. In 2, the Cu(II) ions are linked through the L2 ligands to form 1-D ladder-like chains with 60-membered metallocycles, whereas complexes 3 and 4 form 1-D zigzag chains. In complexes 5 and 6, the Na(I) ions are linked by the L3 ligands to form 2-D layer structures in which the [Hg2X5]− anions are in the cavities. The L2 ligand acts only as a bridging ligand, while L1 and L3 show both chelating and bridging bonding modes. The L1 ligand in 1 adopts a trans-anti conformation and the L2 ligand in 2 adopts both the cis-syn and trans-anti conformations, whereas the L3 ligands in 3–6 adopt the trans conformation. 相似文献
19.
The synthesis, structure, spectroscopic and electro-spectrochemical properties of sterically constrained Schiff-base ligands (LnH) (n = 1, 2, and 3) (L = N-[m-(methylmercapto)aniline]-3,5-di-t-butylsalicylaldimine, m = 4, 3, and 2 positions, respectively) and their copper(II) complexes [Cu(Ln)2] are described. Three new dissymmetric bidentate salicylaldimine ligands containing a donor set of ONNO were prepared by reaction of different primary amine with 3,5-di-t-butyl-2-hydroxybenzaldehyde (3,5-DTB). The copper(II) metal complexes of these ligands were synthesized by treating an methanolic solution of the appropriate ligand with an equimolar amount of Cu(Ac)2 · H2O. The ligands and their copper complexes were characterized by FT-IR, UV–Vis, 1H and 13C NMR and elemental analysis methods in addition to magnetic susceptibility, molar conductivity, and spectroelectrochemical techniques. Analytical data reveal that copper(II) metal complexes possess 1:2 metal–ligand ratios. On the basis of molar conductance, the copper(II) metal complexes could be formulated as [Cu(Ln)2] due to their non-electrolytic nature in dimethylforamide (DMF). The room temperature magnetic moments of [Cu(Ln)2] complexes are in the range of 1.82–1.90 B.M which are typical for mononuclear of Cu(II) compounds with a S = 1/2 spin state. The complexes did not indicate antiferromagnetic coupling of spin at this temperature. Electrochemical and thin-layer spectroelectrochemical studies of the ligands and complexes were comparatively studied in the same experimental conditions. The results revealed that all ligands displayed irreversible reduction processes and the cathodic peak potential values of (L3H) are shifted towards negative potential values compared to those of (L1H) and (L2H). It is attributed to the weak-electron-donating methyl sulfanyl group substituted on the ortho (m = 2) position of benzene ring. Additionally, all copper complexes showed one quasi-reversible one-electron reduction process in the scan rates of 0.025–0.50 V s−1, which are assigned to simple metal-based one-electron processes; [Cu(2+)(Ln)2] + e− → [Cu(1+)(Ln)2]−. The spectral changes corresponding to the ligands and complexes during the applied potential in a thin-layer cell confirmed the ligand and metal-based reduction processes, respectively. 相似文献
20.
The quinolinylcyclopalladated complexes 3a–b were synthesised in good yields (81% and 77%) by the insertion reaction of the prepared dinuclear palladium complexes [Pd(C,N-2-C9H4N-CHO-3-R-6)Cl(PPh3)]2 [(R = H (2a), R = OMe (2b)] with isonitrile XyNC (Xy = 2,6-Me2C6H3). The cyclopalladated complexes 3a–b were also obtained in low yields (39% and 33.5%) via a one pot oxidative addition reaction of quinoline chloride 1a–b with isonitrile XyNC:Pd(dba)2 (4:1). The reactions of 3a–b with Tl(TfO) (TfO = triflate, CF3SO3) in the presence of H2O or EtOH causes depalladation reactions of the complexes to provide the corresponding organic compounds 4a–b, 5a–b and 6a–b in yields (41%, 27% and 18–19%). The products were characterized by satisfactory elemental analyses and spectral studies (IR, 1H, 13C and 31P NMR). The crystal structures of 2a, 3a and 3b were determined by X-ray diffraction studies. 相似文献