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1.
Paolo Sgarbossa Alessandro Scarso Armando J.L. Pombeiro 《Inorganica chimica acta》2008,361(11):3247-3253
The electrochemical behavior of the Pt(II)-based Baeyer-Villiger catalysts of the general formulae [Pt(μ-OH)(P∩P)]2(BF4)2 (P∩P = dppe (1a), 2Fdppe (1 b), 4Fdppe (1c), dfppe (1d), dmpe (1e), depe (1f), dippe (1g), dtbpe (1h)) and [Pt(OH2)2(P∩P)](OTf)2 (P∩P = dppe (2a), 2Fdppe (2b), 4Fdppe (2c), dfppe (2d)) is reported. They exhibit irreversible reduction processes whose potentials reflect the Lewis acidity of the metal centres, showing (for the aromatic diphosphine complexes) overall relations with the number of fluorine atoms, with JPt-P, with the ν(CN) coordination shift of a ligand isocyanide probe and with the catalytic activity. Single-crystal X-ray diffraction analyses were carried out for [Pt(μ-OH)(4Fdppe)]2(BF4)2 (1c) and [Pt(μ-OH) (dippe)]2(BF4)2 (1g). 相似文献
2.
Three kinds of crystalline compounds containing the nitrosylpentaamminechromium complexes [Cr(NO)(NH3)5]2+(A) were obtained: chloride ACl2 (red-orange), chloride perchlorate ACl(ClO4) (brown), and perchlorate A(ClO4)2 (green). The cause of the color change of the complex A with the change of outer sphere anions was sought using X-ray structural data of ACl2, ACl(ClO4), and A(ClO4)2. Crystal data: ACl2, orthorhombic, space group Cmcm, a=10.0236 (9) Å, b=9.098 (3) Å, c=10.357(1) Å, V=944.5 (5) Å3, Z=4; ACl(ClO4), tetragonal, space group P4/nmm, a=7.6986 (8) Å, c=9.9566(8) Å, V=590.1 (1) Å3,Z=2; A(ClO4)2, orthorhombic, space group Pnma, a=15.760 (2) Å, b=11.480(2) Å, c=7.920 (2) Å, V=1432.9 (4) Å3, Z=4. The complex cation in ACl2 has a distorted octahedral structure with a linear CrNO moiety. The short CrN (nitrosyl) distance of 1.692 (7) Å indicates the presence of multiple bonding between the chromium atom and the nitrogen atom in the nitrosyl group. The interatomic distances and angles within the complex cations hardly change with the change of the counter anions, while the distances between the complex cations in each crystal increase in the order ACl2<ACl(ClO4)<A(ClO4)2. The bulky perchlorate anions seems to separate the complex cations, while smaller chloride anions are not large enough to separate them. The distance (3.213(5) Å) between O(NO) and N(NH3 in the adjacent complex cation) is rather short in the crystal of ACl2, and there are six hydrogen bonds, where the NO group is surrounded by four NH3 ligands. The distance (4.002(5) Å) between O(NO) and N(NH3) is much longer in the crystal of A(ClO4)2, indicating the presence of no hydrogen bonding. In the crystal of ACl(ClO4) the distance (3.452(4) Å) between O(NO) and N(NH3) is in between those of ACl2 and A(ClO4)2. The presence of hydrogen bonding between O(NO) and N(NH3 in the adjacent complex cation) seems to cause the color change with the change of outer sphere anions. 相似文献
3.
Using a phosphorus based Mannich condensation reaction the new pyridylphosphines {5-Ph2PCH2N(H)}C5H3(2-Cl)N (1-Cl) and {2-Ph2PCH2N(H)}C5H3(5-Br)N (1-Br) have been synthesised in good yields (60% and 88%, respectively) from Ph2PCH2OH and the appropriate aminopyridine. The ligands 1-Cl and 1-Br display variable coordination modes depending on the choice of late transition-metal complex used. Hence P-monodentate coordination has been observed for the mononuclear complexes AuCl(1-Cl) (2), AuCl(1-Br) (3), RuCl2(p-cymene)(1-Cl) (4), RuCl2(p-cymene)(1-Br) (5), RhCl2(Cp∗)(1-Cl) (6), RhCl2(Cp∗)(1-Br) (7), IrCl2(Cp∗)(1-Cl) (8), IrCl2(Cp∗)(1′-Cl) (8′), IrCl2(Cp∗)(1-Br) (9), cis-/trans-PdCl2(1-Cl)2 (10), cis-/trans-PdCl2(1-Br)2 (11), cis-PtCl2(1-Cl)2 (12) and cis-PtCl2(1-Br)2 (13). Reaction of Pd(Me)Cl(cod) (cod = cycloocta-1,5-diene) with either 1 equiv. of 1-Br or the known pyridylphosphines 1′-Cl, 1-OH or 1-H gave the P/N-chelate complexes Pd(Me)Cl(1-Br-1-H) (14)-(17). All new compounds have been fully characterised by spectroscopic and analytical methods. Furthermore the structures of 4, 5, 10 and 16 · (CH3)2SO have been elucidated by single crystal X-ray crystallography. A crystal structure of the dinuclear metallocycle trans,trans-[PdCl2{μ-P/N-{Ph2PCH2N(H)}C5H4N}]2 · CHCl3, 18 · CHCl3, has also been determined. Here 1-H bridges, using both P and pyridyl N donors, two dichloropalladium centres affording a 12-membered ring with the PdCl2 units adopting a head-to-tail arrangement. 相似文献
4.
Biswarup Chakraborty 《Inorganica chimica acta》2011,378(1):231-238
The syntheses and structural characterization of four cobalt(II)-salicylate complexes, [(TPA)CoII(HSA)](ClO4) (1), [(isoBPMEN)CoII(HSA)](BPh4) (2), [(TPzA)CoII(HSA)](ClO4) (3) and [(6Me3TPA)CoII(HSA)](BPh4) (4) [TPA = tris(2-pyridylmethyl)amine, isoBPMEN = N1,N1-dimethyl-N2,N2-bis(2-pyridylmethyl)ethane-1,2-diamine, TPzA = tris((3,5-dimethyl-1H-pyrazole-1-yl)methyl)amine and 6Me3TPA = tris(6-methyl-2-pyridylmethyl)amine] are described. While 2, 3 and 4 are unreactive towards dioxygen, 1 reacts slowly with molecular oxygen to a cobalt(III)-salicylate complex, [(TPA)CoIII(SA)](ClO4) (1a). Two different crystalline forms, 1a and 1a·4H2O were isolated depending upon the condition of oxidation and crystallization. The solid-state structures of cobalt(III)-salicylate unit in both 1a and 1a·4H2O show a six-coordinate distorted octahedral coordination geometry at the cobalt(III) center ligated by the tetradentate ligand (TPA) where the dianionic salicylate (SA) binds in a bidentate fashion through one carboxylate and one phenolate oxygen. The hydrated form 1a·4H2O reveals a hexameric water cluster formation in the inorganic lattice host. The complex cation and the perchlorate counterion are involved in stabilizing the (H2O)6 cluster in a rare ‘pentamer planar+1’ conformation. A one-dimensional water tape consisting of edge-shared water hexamers is observed. The water tape represents a subunit of ice structure. 相似文献
5.
Rojalin Sahu 《Inorganica chimica acta》2010,363(14):4008-4016
Four new hetero-bimetallic Co3+-Na+ and Co3+-K+ coordination polymers having the molecular formulae [Na(H2O)Co(L)(N3)3]n (1), [Na2Co(L)(N3)3(H2O)5][Co(L)(N3)3] (2), K[Co(L)(NCS)3]·H2O (3) and K[Co(L)2][Co(NCS)4]·0.5H2O (4), were synthesized. Compounds 1-4 were characterized by single crystal X-ray diffraction, IR, UV-Vis, and thermogravimetric methods. These bimetallic systems have EE, EO azide bridge (1, 2) as well as bent (1, 2, 3) and linear (1, 4) aquo bridges. Important features observed among them were: a Z-shaped and diamond-shaped Co2Na2 clusters in 1, a centrosymmetric double ladder like polymer based on Na4 cluster in 2, and a linear KOK core having paddle-wheel structure in 4. 相似文献
6.
The dinuclear bis(6-X-pyridin-2-olato) ruthenium complexes [Ru2(μ-XpyO)2(CO)4(PPh3)2] (X = Cl (4B) and Br (5B)), [Ru2(μ-XpyO)2(CO)4(CH3CN)2] (X = Cl (6B), Br (7B) and F (8B)) and [Ru2(μ-ClpyO)2(CO)4(PhCN)2] (9B) were prepared from the corresponding tetranuclear coordination dimers [Ru2(μ-XpyO)2(CO)4]2 (1: X = Cl; 2: X = Br) and [Ru2(μ-FpyO)2(CO)6]2 (3) by treatment with an excess of triphenylphosphane, acetonitrile and benzonitrile, respectively. In the solid state, complexes 4B-9B all have a head-to-tail arrangement of the two pyridonate ligands, as evidenced by X-ray crystal structure analyses of 4B, 6B and 9B, in contrast to the head-to-head arrangement in the precursors 1-3. A temperature- and solvent-dependent equilibrium between the yellow head-to-tail complexes and the red head-to-head complexes 4A-7A and 9A, bearing an axial ligand only at the O,O-substituted ruthenium atom, exists in solution and was studied by NMR spectroscopy. Full 1H and 13C NMR assignments were made in each case. Treatment of 1 and 2 with the N-heterocyclic carbene (NHC) 1-butyl-3-methylimidazolin-2-ylidene provided the complexes [Ru2(μ-XpyO)2(CO)4(NHC)], X = Cl (11A) or Br (12A). An XRD analysis revealed the head-to-head arrangement of the pyridonate ligands and axial coordination of the carbene ligand at the O,O-substituted ruthenium atom. The conversion of 11A and 12A into the corresponding head-to-tail complexes was not possible. 相似文献
7.
Polynuclear self-assembly molecules of general formula [{Pd(en)}x(ligand)y](NO3)2x (A) undergo ligand exchange reaction when heated in DMSO. A mixture of [Pdm(ligand)n](NO3)2m (B) and [Pd(en)2](NO3)2 (C) is generated in this process. The binuclear compound (A) containing a bidentate, non-chelating ligand 1,4-bis(4′-pyridylmethyl)-2,3,5,6-tetrafluorobenzene, is subjected to ligand exchange where upon the compound (A) remains in a dynamic equilibrium with the mixture of ensuing (B) and (C). Combination of separately prepared (B) and (C) also generates (A), thus equilibrium of (A) with (B) and (C) is again observed. We predict [{Pd(bpy)}x(ligand)y](NO3)2x (A′) where 2,2′-bipyridyl (bpy) is the cis-protecting group would not probably undergo ligand exchange. The idea was conceived from the fact that (bpy) is more rigid compared to (en) moreover one of the expected products in the event of ligand exchange [Pd(bpy)2](NO3)2 (C′) is not really very stable unlike (C). In fact, when (A′) is heated in DMSO no ligand exchange is observed at all. More interestingly combination of (B) and (C′) generated (A′) smoothly. Mononuclear complexes obtained from the ligand 4-phenylpyridine are also used for similar study for comparison. It is suggested that (bpy) could serve as a better cis-protecting group for Pd(II)-based self-assembly coordination cage compounds particularly when dissolution of the assemblies in polar solvents and heating of the resultant solution is required. 相似文献
8.
Andrey I. Poddel'sky Vladimir K. Cherkasov Georgy K. Fukin Michael P. Bubnov Ludmila G. Abakumova Gleb A. Abakumov 《Inorganica chimica acta》2004,357(12):3632-3640
New square planar CoII(ISQ-iPr)2 (1), CoII(ISQ-Me)2 (2) and five-coordinate CoIII(ISQ-Me)2Cl cobalt complexes (3) (ISQ-iPr=4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-iminobenzosemiquinonate radical-anion, ISQ-Me=4,6-di-tert-butyl-N-(2,6-di-methylphenyl)-o-iminobenzosemiquinonate radical-anion) have been prepared using different methods. Complexes 1-3 have been characterized by IR, UV-Vis, EPR spectroscopy. Molecular structures of 1 and 3 were determined using X-ray crystallography. It has been established from variable-temperature magnetic susceptibility measurements and X-band EPR spectroscopy that 1 and 2 possess an S=1/2 ground state. In the complex molecules the unpaired electrons of o-iminobenzosemiquinonate radical ligands (Srad=1/2) are strongly coupled antiferromagnetically. The sterical hindrances of N-aryl in o-iminobenzosemiquinonate ligands prevent the formation of a hexacoordinate species. 相似文献
9.
A series of coordination polymers have been prepared by the combination of flexible ligand 1,1′-biphenyl-2,2′-dicarboxylic acid (H2dpa) and different types of nitrogen-containing ligands, with various metal ions such as Co(II), Zn(II) and Cd(II). The single-crystal structure analyses reveal that the above complexes possess different structure features with the introduction of different nitrogen-containing ligands. When auxiliary linear ligand 4,4′-bipyridine (4,4′-bpy) is introduced, two-dimensional layered complex, [Co2(dpa)2(4,4′-bpy)2(H2O)]n (1) is formed. Whereas if chelating ligand, 1,10-phenanthroline (1,10′-phen) and 2,2′-bipyridine (2,2′-bpy) are introduced, one-dimensional complex [Zn(dpa)(1,10′-phen)]n (2) and discrete complexes [Co2(dpa)2(2,2′-bpy)2(H2O)2] (3), [Co3(dpa)3(1,10′-phen)6(H2O)2] (4), [Cd(dpa)(1,10′-phen)2][(H2dpa)2(H2O)2] (5) are synthesized. To our interest, 1 and 2 crystallize in homochiral spacegroup. Furthermore, the magnetic property of complex 1 and the fluorescent properties of complexes 2 and 5 are studied. 相似文献
10.
The synthesis and characterisation of eight new octahedral PtIV complexes of the type trans,trans,trans-[Pt(N3)2(OH)2(NH3)(Am)] where Am = methylamine (2), ethylamine (4), thiazole (6), 2-picoline (8), 3-picoline (10), 4-picoline (12), cyclohexylamine (14), and quinoline (16) are reported, including the X-ray crystal structures of complexes 2, 8, and 14 as well as that of two of the precursor PtII complexes (trans-[Pt(N3)2(NH3)(methylamine)] (1) and trans-[Pt(N3)2(NH3)(cyclohexylamine)] (13)). Irradiation with UVA light rapidly induces loss in intensity of the azide-to-PtIV charge-transfer bands and gives rise to photoreduction of platinum. These complexes have potential for use as photoactivated anticancer agents. 相似文献
11.
The lithium β-diketiminate (1c, [Li{N(2,6-iPr2C6H3)C(Ph)CHC(tBu)NH}]2 represented as (LiL)2) reacted with 3d-metal (II) chlorides to afford the corresponding compounds (2-7). All metal compounds were fully characterized by elemental, spectroscopic analyses and the single-crystal X-ray diffraction. The coordination geometries around the metals are shown to be tetrahedral within the trinuclear Co2Li compound (2), planar in ML2 (M = Co, 3), pseudo-tetrahedral conformation in the ML2 with M as Mn (4), Fe (5) or Zn (6), and square planar in the dinickel compound (7). Indicated by the trimetallic Co2Li compound 2, a six-membered ring is constructed of three metal atoms and three bridged chlorides as a twisted conformation. An inversion center is present in the centroid of the Ni2Cl2 four-membered ring within compound 7. The plausible mechanism of forming ML2 was proposed through the chloro-bridged multinuclear compounds on the basis of isolated intermediates of trinuclear (2) and dinuclearic (7) compounds. Upon treatment with methylaluminoxane (MAO), the nickel compound 7 possessed good activity towards ethylene oligomerization, whereas the other metal compounds showed moderate activities towards ethylene polymerization. 相似文献
12.
Gerard A. van Albada Wen Tian Fu Ilpo Mutikainen Jan Reedijk 《Inorganica chimica acta》2009,362(12):4422-3393
Using the ligand 1,4,5-triazanaphthalene (abbreviated as tan) in combination with Cu(II) salts, three mononuclear compounds, Cu(tan)2Cl2 (1), Cu(tan)2Br2 (3), Cu(tan)2(NO3)2 (5) and three polynuclear compounds, [Cu(tan)Cl2]n (2), [Cu(tan)Br2]n (4), [Cu(tan)(NO3)2]n (6) have been synthesized and characterized by UV-Vis, EPR, FTIR and Far-FTIR spectroscopies. The crystal structures of compounds 1, 3, 5 and 6 are reported, as well as that of the dioxane adduct of compound 4, [Cu(tan)Br2(C4H8O2)](C4H8O2) (4A).The structure of (2) was solved by X-ray powder diffraction. The coordination geometry around the Cu(II) atoms is tetrahedral for (1) and (3), square-pyramidal for (4A) and distorted octahedral for (5) and (6). Magnetic susceptibility measurements on the polynuclear compounds revealed weak antiferromagnetic interactions between the Cu(II) atoms with interaction constants (J) of J = −9.1 and −10.5 cm−1, for 4 and 6, respectively. For compound 2 two options for possible interactions were considered, with interaction constants which vary for Jrung −22.0 to −13.5 cm−1 and Jrail −19.6 to −17.0 cm−1. These figures are discussed in the light of relevant structural parameters and literature. 相似文献
13.
Silvia Melnic Charles Simmons Tatiana Chiriac Valeriu Rudic 《Inorganica chimica acta》2011,373(1):167-172
New trinuclear iron(III) furoates with the general formula [Fe3O(α-fur)6(R-OH)3]X, where α-fur C4H3OCOO, R = CH3 (1), C2H5 (2), n-C3H7 (3), n-C4H9 (4), X = NO3− (1-4); [Fe3O(α-Fur)6(DMF)(CH3OH)2]NO3 (5); [Fe3O(α-Fur)6(H2O)(CH3OH)2]Cl (6); [Fe2MO(α-Fur)6(L)(H2O)2], where L = THF (7-9), DMF (10-12), M = Mn2+ (7, 10), Co2+ (8, 11), Ni2+ (9, 12) and [Fe2MO(α-Fur)6(3Cl-Py)3], where M = Mn2+ (13), Co2+ (14), Ni2+ (15); have been prepared and investigated by Mössbauer and IR spectroscopy. The X-ray crystal structure for the 1·2CH3OH complex indicates that it crystallizes in the monoclinic crystal system (P21/n) and has a structure typical of μ3-O-bridged trinuclear iron(III) compounds. Coordination compounds 1, 4, 7, 8 can be used as regulators of the biochemical composition of cyanobacterium Spirulina platensis biomass. The supplementation of these compounds, in concentrations exceeding 5-10 mg/l, increases the content of iron, amino acids, peptides and carbohydrates in Spirulina. 相似文献
14.
Seven copper complexes [Cu(L1)I2] (1), [Cu2(L1)2I2]2[Cu2(μ-I)2I2] (2), [Cu(L2)I2] (3), [Cu2(L2)(μ-I)I(PPh3)] (4), [Cu4(L2)2(μ-I)2I2] (5), {[Cu(L2)I]2[Cu2(μ-I)2I2]}n (6) and [Cu2(L2)(μ-I)2]n (7) have been prepared by reactions of ligands: 4′-(2-pyridyl)-2,2′:6′,2″-terpyridine (L1) and 4′-(3-pyridyl)-2,2′:6′,2″-terpyridine (L2) with CuI in hydrothermal conditions, respectively. By alternating the oxidations states of the metal centers, increasing stoichiometric metal/ligand ratio and introducing a second ligand, the compounds, were successfully developed from mononuclear (1 and 3) to multinuclear (2, 4 and 5) and polymers (6 and 7). The synthesis of these compounds may provide an approach for the construction of coordination compounds of 4′-pyridyl terpyridine with different nuclearity. 相似文献
15.
R.M. Medina M.L. Marcos F. Benito S. Delgado M.J. Macazaga 《Inorganica chimica acta》2004,357(7):2069-2080
The preparation and characterisation of the complexes [Co2(CO)4(PMe3)2][Co2(CO)6](Me3SiC2C2SiMe3) (4), [Co2(CO)4(dppm)][Co2(CO)6](Me3SiC2C2H) (5), [Co2(CO)4(dppa)][Co2(CO)6](Me3SiC2C2SiMe3) (6), [Co2(CO)4(dppm)]2[Co2(CO)6](Me3SiC2CCC2C2SiMe3) (7) and [{SiMe3(Co2(CO)4(dppm))C2}2(HCC)(1,3,5-C6H3)] (8) are described. An electrochemical study of the complexes 5-8 and of the related [Co2(CO)4(dppm)]2(Me3SiC2(CC)2C2SiMe3) (1), [Co2(CO)4(dppa)]2(Me3SiC2C2SiMe3) (2) and [{SiMe3(Co2(CO)4(dppm))C2}(HCC)2(1,3,5-C6H3)] (3) is presented by means of the cyclic and square-wave voltammetry techniques. Crystals of 8 suitable for single-crystal X-ray diffraction were grown and the molecular structure of this compound is discussed. 相似文献
16.
A series of Ru(II) polypyridyl complexes [Ru(bpy)2(ptdb)](ClO4)2 (1), [Ru(bpy)2(ptda)](ClO4)2 (2) and [Ru(bpy)2(ptdp)](ClO4)2 (3) with asymmetric intercalative ligands have been synthesized and characterized by EA, mass spectra, 1H NMR and cyclic voltammetry. The crystal structure of complex 1 has been determined. The DNA-binding properties of the complexes were investigated by absorption titration, luminescence spectroscopy and viscosity measurements. The experimental results suggest that all these complexes bind to DNA in an intercalation mode. The results also show that the order of DNA-binding affinities (A) of this series of complexes is A(1) < A(2) < A(3). It is further confirmed that a ligand planarity of the complexes is a very important factor in affecting the DNA-binding behaviors of such complexes. Theoretical studies for these complexes were also carried out with the density functional theory (DFT) method. The trend in the DNA-binding affinities of this series of complexes can be reasonably explained by the synthetical considerations of the calculated planarity of intercalative ligands, some frontier molecular orbital energies of the complexes and the planarity area (S) of the intercalative ligands. 相似文献
17.
Marina V. Kirillova 《Inorganica chimica acta》2007,360(2):506-512
The heteronuclear water-soluble and air-stable compounds [M(H2O)5M′(dipic)2] · mH2O (M/M′ = CuII/CoII (1), CuII/NiII (2), CuII/ZnII (3), ZnII/CoII (4), NiII/CoII (5), m = 2-3; H2dipic = dipicolinic acid) have been prepared by self-assembly synthesis in aqueous solution at room temperature, and characterized by IR, UV-Vis and atomic absorption spectroscopies, elemental and X-ray diffraction single crystal (for 1 and 2) analyses. 1-5 represent the first examples of heteronuclear dipicolinate compounds with 3d metals. Extensive H-bonding interactions involving all aqua ligands, dipicolinate oxygens and lattice water molecules further stabilize the dimetallic units by linking them to form three-dimensional polymeric networks. 相似文献
18.
Aurkie Ray Guillaume Pilet Carlos J. Gómez-García Sebastián Bellú 《Inorganica chimica acta》2011,375(1):20-30
A tridentate NNO donor Schiff base ligand [(1Z,3E)-3-((pyridin-2-yl)methylimino)-1-phenylbut-1-en-1-ol = LH] in presence of azide ions coordinates with cobalt(II) and copper(II) ions giving rise to three new coordination complexes [Co2(L)2(μ1,1-N3)2(N3)2] (1), [Cu2(L)2(μ1,3-N3)]·ClO4 (2) and [(μ1,1-N3)2Cu5(μ-OL)2(μ1,1-N3)4(μ1,1,1-N3)2]n (3). The complexes have been characterized by elemental analysis, FT-IR, UV-Vis spectral studies, and single crystal X-ray diffraction studies. These complexes demonstrate that under different synthetic conditions the azide ions and the Schiff base ligand (LH) show different coordination modes with cobalt(II) and copper(II) ions, giving rise to unusual dinuclear and polynuclear species (1, 2 and 3) whose structural variations are discussed. Magneto-structural correlation for the very rare singly μ1,3-N3 bridged CuII-Schiff base dinuclear species (2) has been studied. In addition, the catalytic properties of 1 for alkene oxidation and the general catalase-like activity behavior of 2 have been discussed. 相似文献
19.
Xin-Hui Zhou 《Inorganica chimica acta》2006,359(5):1442-1448
Six copper(I) complexes {[Cu2(L1)(PPh3)2I2] · 2CH2Cl2}n (1), {[Cu2(L2)(PPh3)2]BF4}n (2), [Cu2(L3)(PPh3)4I2] · 2CH2Cl2 (3), [Cu2(L4)(PPh3)4I2] (4), [Cu2(L5)(PPh3)2I2] (5) and [Cu2(L6)(PPh3)2I2] (6) have been prepared by reactions of bis(schiff base) ligands: pyridine-4-carbaldehyde azine (L1), 1,2-bis(4′-pyridylmethyleneamino)ethane (L2), pyridine-3-carbaldehyde azine (L3), 1,2-bis(3′-pyridylmethyleneamino)ethane (L4), pyridine-2-carbaldehyde azine (L5), 1,2-bis(2′-pyridylmethyleneamino)ethane (L6) with PPh3 and copper(I) salt, respectively. Ligand L1 or L2 links (PPh3)2Cu2(μ-I)2 units to form an infinite coordination polymer chain. Ligand 3 or 4 acts as a monodentate ligand to coordinate two copper(I) atoms yielding a dimer. Ligand 5 or 6 chelates two copper(I) atoms using pyridyl nitrogen and imine nitrogen to form a dimer. Complexes 1-4 exhibit photoluminescence in the solid state at room temperature. The emission has been attributed to be intraligand π-π* transition mixed with MLCT characters. 相似文献
20.
The crystal structures of [Cr(NO)(NH3)5](PF6)2 (red) and [Cr(NO)(NH3)5]Cl(PF6) (brown) have been determined. The [Cr(NO)(NH3)5]2+(A) complex cations in these compounds have a slightly distorted octahedral geometry with a strictly linear Cr-N-O arrangement (from symmetry). The short interatomic distances (2.399 Å × 4) between the O (nitrosyl) and H (ammonia in adjacent complex cations) atoms in A(PF6)2 indicate the existence of hydrogen bonds, while the interatomic distances (3.258 Å × 8) between those in ACl(PF6) are much longer, and the hydrogen bonds should be weak in spite of the presence of the smaller counter anion of chloride ion in ACl(PF6). Comparisons of the five crystal structures of A(PF6)2, ACl2, ACl(ClO4), ACl(PF6), and A(ClO4)2 have led to the conclusion that the existence of the strong hydrogen bonds gives red crystals of A(PF6)2, while the absence of hydrogen bonds results in the formation of green crystals of A(ClO4)2 (O ? H, 3.595 Å × 2). The color change of the crystals (from red to green) with the change of outer sphere anions is attributed to the change of the strength of the hydrogen bonding between the complex cations. 相似文献