Synthesis, crystal structures and spectroscopic properties of copper(I) complexes containing beta-dialdiminato supporting ligands

Two mononuclear neutral copper(I) complexes, Cu(L-1)PPh3 (1), Cu(L-2)(PPh3)(2) (2) ([L-1](-) = [{N((C6H3Pr2)-Pr-i-2,6)C(H)}(2)CPh](-); [L-2](-) = [{N(C6H5)C(H)}(2)CPh](-)) have been synthesized and structurally characterized by X-ray crystallography. In complex 1, the copper(I) atom is in a distorted three-coordinate trigonal planar environment, whereas in complex 2 with the less sterically hindered beta-dialdiminato ligand, the copper(I) atom is the centre of a four-coordinate distorted tetrahedron. At room temperature complexes 1 and 2 in a film of PMMA exhibit green emission at 543 and 549 nm with lifetimes of 5.28 and 5.32 ns, respectively.

A monometallic tri-spin single-molecule magnet based on rare earth radicals

A mononuclear tri-spin single-molecule magnet based on the rare earth radical [Tb(hfac)(3)(NITPhOEt)(2)] (NITPhOEt = 4'-ethoxy-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been synthesized, structurally characterized and the alternating current signals show a slow relaxation of magnetization and frequency-dependent signals.

Two-Step Spin-Transition Iron(III) Compound with a Wide [High Spin-Low Spin] Plateau

A new iron(III) coordination compound exhibiting a two-step spin-transition behavior with a remarkably wide [HS-LS] plateau of about 45 K has been synthesized from a hydrazino Schiff-base ligand with an N,N,O donor set, namely 2-methoxy-6-(pyridine-2-ylhydrazonomethyl) phenol (Hmph). The single-crystal X-ray structure of the coordination compound {[Fe(mph)(2)](ClO4)(MeOH)(0.5)(H2O)(0.5)}(2) (1) determined at 150 K reveals the presence of two slightly different iron(III) centers in pseudo-octahedral environments generated by two deprotonated tridentate mph ligands. The presence of hydrogen bonding interactions, instigated by the well-designed ligand, may justify the occurrence of the abrupt transitions. 1 has been characterized by temperature-dependent magnetic susceptibility measurements, EPR spectroscopy, differential scanning calorimetry, and Fe-51 Mossbauer spectroscopy, which all confirm the occurrence of a two-step transition. In addition, the iron(III) species in the high-spin state has been trapped and characterized by rapid cooling EPR studies.

Synthesis and structural characterization of new tungsten(VI) complexes with polycarboxylate ligands

The reactions of (NH4)(2)WS4 and three polycarboxylate ligands {including nitrilotriacetate (nta(3-)), citrate (Hcit(3-)) and ethylenediaminetetra acetate (EDTA(4-))} in H2O/EtOH at ambient temperature have resulted in three new trioxotungsten (VI) complexes, K-3[WO3(nta)]center dot H2O 1, (NH4)(4)[WO3(cit)]center dot 2 H2O 2 and K-2(NH4)(2)[W2O6(EDTA)]center dot 4H(2)O 3, respectively. These three complexes have been characterized by IR, XPS, TGA-DTA, H-1 and C-13 NMR spectroscopy. And their structures have been determined by X-ray crystallographic studies, which confirm that I and 2 are mononuclear compounds and 3 is a binuclear compound. Each tungsten atom in 1-3 is coordinated to three unshared oxygen atoms, which adopt fac stereochemistry, while the remaining fac positions are occupied by three atoms from the ligands. The electrochemical properties of 2 and 3 have been investigated.

Novel heteroleptic Cu-I complexes with tunable emission color for efficient phosphorescent light-emitting diodes

A series of orange-red to red phosphorescent heteroleptic Cu-I complexes (the first ligand: 2,2 '-biquinoline (bq), 4,4 '-diphenyl2,2 '-biquinoline (dpbq) or 3,3 '-methylen-4,4 '-diphenyl-2,2 '-biquinoline (mdpbq); the second ligand: triphenylphosphine or bis[2-(diphenylphosphino)phenyl]ether (DPEphos)) have been synthesized and fully characterized. With highly rigid bulky biquinoline-type ligands, complexes [Cu(mdpbq)(PPh3)(2)](BF4) and [Cu(mdpbq)(DPEphos)](BF4) emit efficiently in 20 wt % PMMA films with photoluminescence quantum yield of 0.56 and 0.43 and emission maximum of 606 nm and 617 nm, respectively. By doping these complexes in poly(vinyl carbazole) (PVK) or N-(4-(carbazol-9-yl)phenyl)-3,6-bis(carbazol-9-yl) carbazole (TCCz), phosphorescent organic light-emitting diodes (OLEDs) were fabricated with various device structures. The complex [Cu(mdpbq)(DPEphos)](BF4) exhibits the best device performance. With the device structure of ITO/PEDOT/ TCCz:[Cu(mdpbq)(DPEphos)](BF4) (15 wt %)/TPBI/LiF/Al (III), a current efficiency up to 6.4 cd A(-1) with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.61, 0.39) has been realized. To our best knowledge, this is the first report of efficient mononuclear Cu complexes with red emission.

Highly efficient green phosphorescent organic light-emitting diodes based on Cu-I complexes

Mononuclear Cu-I complexes with mixed ligands are used to fabricate green phosphorescent organic light-emitting diodes. The electroluminescence (EL) maximum at 524 nm coincides well with its photoluminescent (PL) spectrum in poly(methyl methacrylate) film (see Figure). A maximum current efficiency of 10.5 cd A(-1) at 105 cd m(-2) and a maximum brightness up to 1663 cd m(-2) are

Syntheses and crystal structures of four new organotin complexes with Schiff bases containing triazole

Four new organotin complexes, namely [(Bu2Sn)(2)O(EtO)(L1)](2) (1), [(Bu2Sn)(2)O(EtO)(L2)](2) (2), [(Bu2Sn)(2)O(EtO)(L-3)](2) (3) and [Ph3Sn(L4)]center dot 0.5H(2)O (4), were obtained by reactions of Bu2SnO and Ph3SnOH with 4-phenylideneamino-3-methyl-1,2,4-triazole-5-thione (HL1), 4-furfuralideneamino-3-methyl-1,2,4-triazole-5-thione (HL2), 4-(2-thienylideneamino)-3-ethyl-1,2,4-triazole-5-thione (HL3) and 4-(3,5-di-t-butylsalicylideneamino)-3-ethyl-1,2,4-triazole-5-thione (HL4). Compounds 1-4 were characterized by elemental analysis, IR spectra and their structures were determined by single-crystal X-ray diffraction methods. Complexes 1-3 show similar structures containing a Sn4O4 ladder skeleton in which each of the exo tin atoms is bonded to the N atom of a corresponding thione-form deprotonated ligand. Complex 4 shows a mononuclear structure in which the tin atom of triphenyltin group is coordinated by the S atom of a thiol-form L4(-) anion.

Syntheses, crystal structures and magnetic properties of two heterometallic coordination polymers

Two heterometallic chain coordination polymers with the chemical formula {[Cu2Mn2L2(CH3OH)(H2O)] center dot 0.5CH(3)OH center dot 0.5CH(3)CH(2)OH}(n) (1) and {[Cu2Co2L2(H2O)(2)] center dot H2O}(n) (2) have been synthesized and characterized by IR, UV spectroscopy and single-crystal X-ray structural analysis, where H4L = 2-hydroxy-3-[(E)-({2-[(2-hydroxybetizoyl)amino]ethyl}imino)methyl] benzoic acid. Magnetic measurements showed that the two compounds exhibit antiferromagnetic coupling exchange interactions, and satisfactory fittings to the observed magnetic susceptibility data were obtained by assuming a linear four-spin arrangement with two isotropic magnetic exchange interactions.

Synthesis, crystal structure and magnetic properties of a chain coordination polymer {[Cu4L2(H2O)] center dot H2O}(n)

A chain coordination polymer with the chemical formula {[Cu4L2(H2O)] (.) H2O)(n), has been synthesized by the assembly reaction of K(2)CuL(.)1.5H(2)O and Cu(OAC)(2)(H2O)-H-. with a 1:1 mole ratio in methanol., where H4L=2-hydroxy-3-[(E)-({2-[(2-hydroxybenzoyl)imino]ethyl I imino)methyl] benzoic acid, OAC(-) = CH3COO-. The crystal structure was determined by single-crystal X-ray diffraction analysis, the compound has chain molecular structure formed by dissymmetrical tetranuclear units. The magnetic measurements showed that Cu-Cu of the complex exhibit antiferromagnetic interactions, and satisfactory fittings to the observed magnetic susceptibility data were obtained by assuming a binuclear system, and further using molecular field approximation to deal with magnetic exchange interactions between binuclear systems.

Syntheses, structures and luminescence of silver(I) sulfonate complexes with PPh3 ligand

In this paper, four new luminescent silver(I) sulfonate complexes with PPh3, namely Ag(L1)(PPh3)(2) (1), Ag(L2)(PPh3)(3) (2), [Ag-2(L3)(PPh3)(4) (H2O)center dot 1.5CH(3)CN center dot 0.5H(2)O (3) and [Ag-4(L4)(PPh3)(10)]center dot 8H(2)O (4), where L1=p-toluenesulfonate, L2=1-naphthalenesulfonate, L3=3-carboxylate-4-hydroxybenzenesulfonate, L4=1, 3, 6, 8-pyrenetetrasulfonatc and PPh3=triphenylphosphine, have been synthesized and characterized. The crystal structures were determined by single-crystal X-ray diffraction method. Compounds 1, 2, 3 and 4 adopt discrete structures rather than polymeric structures. Compounds I and 2 show mononuclear structures while 3 and 4 are dinuclear and tetranuclear molecules, respectively. Moreover the numbers of PPh3 molecules coordinating to one silver center are two or three. The photoluminescent properties of 1, 2 and 3 are discussed.

Synthesis, characterization, crystal structure and magnetic property of asymmetrical double Schiff base heterotrinuclear complex: Cu(II)-Co(II)-Cu(II)

An asymmetrical double Schiff-base Cu(II) mononuclear complex, HCuLp (H(3)Lp is N-3-carboxylsalicylidene-N'-5-chlorosalicylaldehyde-1,3-diaminopropane) and a heterometal trinuclear complex with double molecular structure (CuLp)(2)Co center dot 5H(2)O have been synthesized and characterized by means of elemental analyses, IR and electronic spectra. The crystal structure of the heterotrinucler complex was determined by X-ray analysis. Each asymmetric unit within the unit cell of the complex contains two heterotrinuclear neutral molecules (a) [CuLpCoCuLp], (b) [(CuLpH(2)O) CoCuLp] and four uncoordinated water molecules. In the two neutral molecules, the central Co2+ ions are located at the site of O-6 with a distorted octahedral geometry, one terminal Cu2+ ion (Cu(3)) at the square-pyramidal environment of N2O3, and the other three at the square planar coordination geometry with N2O2 donor atoms. Magnetic properties of the heterotrinucler complex have been determined in the temperature range 5-300 K, indicating that the interaction between the central Co2+ ion and the outer Co2+ ions is antiferromagnetic.

Synthesis, characterization, properties and crystal structure of heterometallic 1D coordination polymers {[CuLZn center dot CuLZn(H2O)]center dot H2O}(n)

Copper-zinc heterometallic 1D chain coordination polymer has been synthesized and characterized by elemental analysis, and IR spectra etc. The crystal structure was determined by single-crystal X-ray diffraction analyses. The title complex is 1 D chain coordination polymer with the chemical formula {[CuLZn center dot CuLZn(H2O)]center dot H2O}(n), where H4L=N-(2-hydroxybenzamido)-N'-(3-carboxylsalicylidene)ethylenediamine. Its structural unit is comprosed of two tetranuclear cycles formed by two dissymmetrical tetranuclear units. These units polymerized each other to form 1 D chain coordination polymer.

Synthesis, characterization and crystal structure of a new layered heterometallic coordination polymer {[(CuL) Sr-2(H2O)center dot Sr-2(H2O)(7)]center dot 2H(2)O center dot 0.5CH(3)OH}(n)

A copper-strontium heterometallic coordination polymer was synthesized and characterized by elemental analysis and IR spectra. The crystal structure was determined by single-crystal X-ray diffraction analyses. The title complex is a 2 D coordination polymer with the chemical formula [[(CuL)(2)Sr (H2O) center dot Sr-2 ((HO)-O-2)(7)]center dot 2H(2)O center dot 0.5CH(3)OH](n), where H4L = N-(2-hydroxybenzamido)-N'-(3-carboxylsalicylidene) ethylenediamine. Its structural unit is comprised of two adjacent units, which polymerized with each other to form a new layered heterometallic coordination polymer.

The photo-induced decarbonylation of Cp ' M(NO)(CO)(2) (M = Cr, Mo, W) with diorgano dichalcogenides (R2E2; E = S, Se; R = Me, Ph)

The photo-induced decarbonylation of Cp'Cr(NO)(CO)(2) (1a) in MeCN solution in the presence of R2E2 (E = S, Se; R = Me, Ph) leads to the formation of chalcogenolato-bridged binuclear complexes Cp-2'Cr-2(NO)(2)(mu -ER)(2) [E = S; R = Me (2a), Ph (3a); E = Se, R = Me (4a), Ph (5a)] while reactions between Cp'M(NO)(CO)(2) [M = Mo (1b), W (1c)] and Ph2E2 (E = S, Se) result in mononuclear complexes Cp'M(NO)(EPh)(2) [M = Mo; E = S (9b), Se (10b); M = W, E = S (11c), Se (12c)]. The corresponding reactions of (1b) with Me2E2 (E = S, Se) yielded both mono and binuclear complexes: Cp'Mo(NO)(SeMe)(2) (8b), Cp-2'Mo-2(NO)(2)(mu -EMe)(2) [E = S (6b), Se (7b)]. The new complexes have been characterized by i.r., H-1-, C-13-n.m.r. spectra and by electron-impact mass spectrometry.

Metallocene polyethylenes with broad or bimodal molecular weight distribution

Seven new binuclear titanocenes with different linking bridges, unsubstituted or substituted on the Cp rings, were synthesized and tested for their effect on ethylene polymerization in the presence of MAO. The polyethylenes thus obtained had broad MWD or even bimodal GPC curves, as compared with that from two reference mononuclear titanocenes. This is explained by the difference in degree of steric hindrance around the active center sites imposed by the bulky substituted ligands assuming different configurations in the rotation of the catalyst molecules. Lower polymerization temperatures alleviate the effect of these configuration differences, as reflected in change in MW and (M) over bar(w)/(M) over bar(n). This effect is not caused by decomposition or disproportionation of the binuclear titanocenes as evidenced by the stability of the catalyst.