Deep Blue Phosphorescence from Platinum Complexes Featuring Cyclometalated N-Pyridyl Carbazole Ligands with Monocarborane Clusters (CB11H12-).

The utilization of deep blue phosphorescent materials in high-performance displays and solid-state lighting requires high quantum efficiencies and color purities. Here, we describe the preparation and luminescent properties of novel platinum triplet emitters featuring cyclometalated N-pyridyl-carbazole ligands functionalized with closo-monocarborane clusters [CB11H12]-. All reported complexes were fully characterized by using standard small molecule techniques (UV-vis, cyclic voltammetry, nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS)), and their solid-state structures were elucidated by X-ray diffraction. These platinum phosphors emit in the blue region of the visible wavelength spectrum in both the solid and solution states. Complex 4a exhibits the highest luminous efficiency at λem = 439 nm with a photoluminescent quantum yield (PLQY) of 60% by dispersing in a PMMA matrix. Electrochemical and computational studies of complexes 4a and 4b revealed that the blue phosphorescence originates mainly from intraligand 3π → π* (3ILCT) transitions with relatively small 3MLCT mixing. A deep-blue OLED containing 4a as the light-emitting dopant was successfully fabricated using a solution-processed method, and the device exhibited blue photoluminescence with CIE coordinates of (0.17, 0.15) and a maximum external quantum efficiency (EQEmax) value of 6.2%. This article represents the pioneering study of a deep blue PhOLED using a Pt complex bearing a closo-monocarborane anion substituent, providing a new avenue into the preparation of novel triplet emitters based on boron-rich cluster anions.

Rational construction of a triphenylphosphine-modified tetra-nuclear Cu(I) coordinated cluster for enhanced chemodynamic therapy.

A triphenylphosphine-modified tetra-nuclear Cu(I) coordinated cluster was constructed for enhanced chemodynamic therapy (CDT) by increasing the number of metal centers. Once inside human bladder cancer (T24) cells, a larger amount of copper accumulated compared with the mono-nuclear Cu(I) complex; the additional copper could generate more •OH and then induce more obvious apoptosis via a Fenton-like reaction, thus further increasing the tumor inhibition effect and ultimately improving the CDT efficiency.

A simple and feasible atom-precise biotinylated Cu(i) complex for tumor-targeted chemodynamic therapy.

A simple and feasible atom-precise biotinylated Cu(i) complex, which can catalyze H2O2 overexpressed commonly in the tumor microenvironment to produce ˙OH through a Fenton-like reaction, was prepared and employed as an effective agent for tumor-targeted chemodynamic therapy.

Constructing an unprecedented {MnII38} matryoshka doll with a [Mn18(CO3)9] inorganic core and magnetocaloric effect.

An unprecedented inner [Mn18(CO3)9] inorganic core and [Mn20] metal-organic periphery compose a high-nuclearity homometallic single-valent {MnII38} molecular aggregate with a [Mn6] ⊂ [Mn12] ⊂ [Mn8] ⊂ [Mn12] matryoshka doll-like skeleton that displays a significant magnetocaloric effect (MCE).

Hierarchical Construction and Magnetic Difference of {Co12M12} (M = Co2+/Cd2+) Aggregates from {Co14} Cluster-Based Precursors in the Presence of Homo/Heterometal Salts.

The controllable construction and function expansion of some sophisticated aggregations represent a current hot topic in scientific research. In this paper, using a prefabricated {Co14} cluster as a synthetic precursor, a homometallic {Co24} and a heterometallic {Co12Cd12} giant cluster possessing similar dual-[M12] (M = Co/Cd) skeletons was prepared by reacting the precursor with excess CoCl2 and Cd(OAc)2 salts, respectively. The detailed structural information on {Co24} and {Co12Cd12} was characterized by single-crystal X-ray diffraction and further analyzed by X-ray photoelectron spectroscopy, inductively coupled plasma-mass spectroscopy, and scanning electron microscopy with energy dispersive X-ray (EDX) spectroscopy in the solid state. Compared to the {Co14} precursor, magnetic difference revealed that spin-canting and magnetic ordering had been enhanced in {Co24} and suppressed in {Co12Cd12} when dotted with diamagnetic Cd2+ ions.

A novel sandwich shaped {CoCoMo} cluster with a Co triangle encapsulated in two capped CoIIICoMoO40 fragments.

A novel discrete {Co14Mo24} nanoscale cluster, {CoIII2CoII10Cl2(dpbt)3(H2O)2[CoIIMoV12O31(CH3O)9]2}·24CH3OH (1) (here, dpbt = 5,5'-di(pyridin-2-yl)-3,3'-bi(1,2,4-triazole)), with a triangular Co4 core encapsulated in two novel capped Co-substituted Keggin-type Co5Mo12O40 anions, has been isolated from alkaline methanol solution. The high-resolution electrospray ionization mass spectrum (HRESI-MS) of microcrystalline 1 in MeOH/CH2Cl2 (v : v = 2 : 1) was recorded. Two prominent overlapping peaks in the range of m/z = 2740-2840 and 1820-1880 for the discrete fragments of [CoIII2CoII12MoV24O62Cl2(dpbt)3(H2O)2(CH3O)x(OH)18-x-2H]2- (x = 9-18, F1) and [CoIII2CoII12MoV24O62Cl2(dpbt)3(H2O)2(CH3O)x(OH)19-x-2H]3- (x = 6-13, F2), respectively, are obtained, confirming the {Co14Mo24} composition in 1. In addition, weak anti-ferromagnetic interactions in 1 are observed.

In Situ Metal-Ligand Reactions under Solvent-Dependent Hydro(solvo)thermal Conditions: Structures, Mass Spectrometry, and Magnetism.

In this study, four in situ hydro(solvo)thermal metal-ligand reactions, including oxidation (H2L1), C-C coupling (H4L2), nitration (H2L3), and condensation (HL4-6), based on bis[3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl]methane (H2L0), in the presence of DyIII ions, were carried out. The in situ metal-ligand reaction gave six new ligands existing in eight novel DyIII coordination complexes, which were characterized by crystal structure, mass spectrometry, and magnetism.

Hierarchical Assembly of a {Co24} Cluster from Two Vertex-Fused {Co13} Clusters and Their Single-Molecule Magnetism.

We present the synthesis, structural characterization, and magnetic properties of two high-nuclearity cobalt clusters formulated as [Co13(µ3-OH)3(µ3-Cl)(dpbt)5(ptd)Cl10][Co(H2O)2Cl2]·(CH3)2CHOH (1) and [Co24(µ3-OH)6(µ3-Cl)2(dpbt)10(ptd)2Cl16]·2CH3CH2OH (2), respectively (H2dpbt = 5,5'-bis(pyridin-2-yl)-3,3'-bis(1,2,4-triazole) and H2ptd = 3-(pyridin-2-yl)-1,2,4-triazine-5,6-diol). Compound 1 is composed of an inner [Co4(µ3-OH)3(µ3-Cl)] cubane and an outer [Co9(dpbt)5(ptd)Cl10] defective adamantane. Compound 2 reveals a giant {Co24} cluster possessing a dual-[Co12] skeleton from 1. The hierarchical assembly from 1 to 2 has been established and tracked through high-resolution electrospray ionization (HRESI-MS) analyses from the solvothermal reaction mother solution. Magnetic studies of 1 and 2 revealed the highly correlated spins, a glasslike magnetic phase transition at ca. 8 K, and slow relaxation behavior of SMM nature in the lower-temperature region (below 4 K).

Ni(II) Complexes with Schiff Base Ligands: Preparation, Characterization, DNA/Protein Interaction and Cytotoxicity Studies.

In this study, two Ni(II) complexes, namely [Ni(HL1)2(OAc)2] (1) and [Ni(L2)2] (2) (where HL1 and HL2 are (E)-1-((1-(2-hydroxyethyl)-1H-pyrazol-5-ylimino)methyl)-naphthalen-2-ol) and (E)-ethyl-5-((2-hydroxynaphthalen-1-yl)methyleneamino)-1-methyl-1H-pyrazole-4-carboxylate, respectively), were synthesized and characterized by X-ray crystallography, Electrospray Ionization Mass Spectrometry (ESI-MS), elemental analysis, and IR. Their uptake in biological macromolecules and cancer cells were preliminarily investigated through electronic absorption (UV-Vis), circular dichroism (CD) and fluorescence quenching measurements. Bovine serum albumin (BSA) interaction experiments were investigated by spectroscopy which showed that the complexes and ligands could quench the intrinsic fluorescence of BSA through an obvious static quenching process. The spectroscopic studies indicated that these complexes could bind to DNA via groove, non-covalent, and electrostatic interactions. Furthermore, in vitro methyl thiazolyl tetrazolium (MTT) assays and Annexin V/PI flow cytometry experiments were performed to assess the antitumor capacity of the complexes against eight cell lines. The results show that both of the complexes possess reasonable cytotoxicities.

Synthesis, characterization, DNA/protein interaction and cytotoxicity studies of Cu(II) and Co(II) complexes derived from dipyridyl triazole ligands.

Four different transition metal complexes containing dipyridyl triazole ligands, namely [Cu(abpt)2Cl2]·2H2O (1), [Cu(abpt)2(ClO4)2] (2), [Co2(abpt)2(H2O)2Cl2]·Cl2·4H2O (3) and [Co2(Hbpt)2(CH3OH)2(NO3)2] (4) have been designed, synthesized and further structurally characterized by X-ray crystallography, ESI-MS, elemental analysis, IR and Raman spectroscopy. In these complexes, the both ligands act as bidentate ligands with N, N donors. DNA binding interactions with calf thymus DNA (ct-DNA) of the ligand and its complexes 1~4 were investigated via electronic absorption, fluorescence quenching, circular dichroism and viscosity measurements as well as confocal Laser Raman spectroscopy. The results show these complexes are able to bind to DNA via the non-covalent mode i.e. intercalation and groove binding or electrostatic interactions. The interactions with bovine serum albumin (BSA) were also studied using UV-Vis and fluorescence spectroscopic methods which indicated that fluorescence quenching of BSA by these compounds was the presence of both static and dynamic quenching. Moreover, the in vitro cytotoxic effects of the complexes against four cell lines SK-OV-3, HL-7702, BEL7404 and NCI-H460 showed the necessity of the coordination action on the biological properties on the respective complex and that all four complexes exhibited substantial cytotoxic activity.

An intuitional hierarchical assembly of cluster-organic frameworks with a thickness of 1.97 nm from a discrete Co14 cluster.

An intuitional hierarchical assembly, metaphorically referred to as a "blossom and yield fruit" process, from a discrete cluster {[Co14(CH3O)4(dpbt)6Cl12]·14CH3OH, ()} to 2D cluster organic frameworks {[Co14(CH3O)10(dpbt)6 Cl6]·12CH3OH, ()}, has been established. The magnetic ordering of was obviously improved compared with .

The Spectroscopy Study of the Binding of an Active Ingredient of Dioscorea Species with Bovine Serum Albumin with or without Co(2+) or Zn(2+).

Diosgenin (DIO) is the active ingredient of Dioscorea species. The interaction of DIO with bovine serum albumin (BSA) was investigated through spectroscopic methods under simulated physiological conditions. The fluorescence quenching data revealed that the binding of DIO to BSA without or with Co(2+) or Zn(2+) was a static quenching process. The presence of Co(2+) or Zn(2+) both increased the static quenching constants K SV and the binding affinity for the BSA-DIO system. In the sight of the competitive experiment and the negative values of ΔH (0) and ΔS (0), DIO bound to site I of BSA mainly through the hydrogen bond and Van der Waals' force. In addition, the conformational changes of BSA were studied by Raman spectra, which revealed that the secondary structure of BSA and microenvironment of the aromatic residues were changed by DIO. The Raman spectra analysis indicated that the changes of conformations, disulfide bridges, and the microenvironment of Tyr, Trp residues of BSA induced by DIO with Co(2+) or Zn(2+) were different from that without Co(2+) or Zn(2+).

Hexaaqua-magnesium(II) bis-{[2-(1-phenyl-1H-tetra-zol-5-yl)sulfan-yl]acetate}.

The asymmetric unit of the title compound, [Mg(H(2)O)(6)](C(9)H(7)N(4)O(2)S)(2), contains one-half of a [Mg(H(2)O)(6)](2+) cation ( symmetry) and one uncoordinated 2-[(1-phenyl-1H-tetra-zol-5-yl)sulfan-yl]acetate anion. The Mg(II) cation is coordinated by six water mol-ecules, exhibiting a slightly distorted octa-hedral coordination. A two-dimensional network parallel to (001) is formed via extensive hydrogen-bonding inter-actions involving the water mol-ecules as donors and the tetra-zole N and carboxyl-ate O atoms of the anion as acceptors. The shortest distance between two adjacent parallel benzene rings is 3.315 (2) Å. The dihedral angle between the benzene ring and the tetra-zole ring is 40.98 (2)°.

Bis(N'-benzoyl-pyridine-4-carbohydrazide)(1,10-phenanthroline)copper(II) dinitrate.

In the title complex, [Cu(C(13)H(11)N(3)O(2))(2)(C(12)H(8)N(2))](NO(3))(2), the Cu(II )atom (site symmetry 2) is coordinated by four N atoms from one 1,10-phenanthroline and two hydrazine ligands, respectively. The hydrazine ligands coordinate to the Cu(II)atom by a pyridine N atom. These four atoms form a slightly distorted square-planar N(4) donor set. In the packing, two additional Cu⋯O inter-actions occur [Cu⋯O = 2.462 (2) Å], resulting in a typical Jahn-Teller-distorted octahedral environment around the Cu atom. N-H⋯O hydrogen bonds result in a three-dimensional network. The O atoms of the anion are disordered over two positions in a 0.68 (2):0.32 (2) ratio.

Potential new inorganic antitumour agents from combining the anticancer traditional Chinese medicine (TCM) liriodenine with metal ions, and DNA binding studies.

Liriodenine (), an active component of the anticancer traditional Chinese medicine (TCM), was isolated from Zanthoxylum nitidum. Its reactions with Pt(II) and Ru(II) afforded three metal complexes: cis-[PtCl2(L)] (), cis-[PtCl2(L)(DMSO)] (), and cis-[RuCl2(L)(DMSO)2].1.5H2O (), the crystal structures of , and were determined by single-crystal X-ray diffraction methods. These complexes were fully characterized by elemental analysis, IR spectrophotometry, 1H and 13C NMR spectroscopies, and ES mass spectrometry. The in vitro cytotoxicity of and complexes against 11 human tumour cell lines was assayed. The metal-based compounds exhibit enhanced cytotoxicity vs. free , suggesting that these compounds display synergy in the combination of metal ions and liriodenine. The binding properties of and its complexes to ct-DNA were investigated through UV-vis, fluorescence, CD spectra, viscosity and agarose gels electrophoretic measurements.

[Investigation of interaction between catechin and bovine serum albumin by spectroscopic methods].

In the present work, the interaction of catechin with bovine serum albumin (BSA) under physiological condition was studied by fluorescence quenching spectra in combination with Fourier transform infrared (FTIR) spectroscopy. The binding constants, the drug-binding mode, the binding site between catechin and BSA in aqueous solution at pH 7.40, and the effect of common ions were studied. The results show that catechin has the ability to quench the intrinsic fluorescence of BSA because of a complex formed, and the quenching mechanism is static quenching. The binding constants K under 296, 303 and 310 K were 2.368, 2.249 and 2.152 x 10(6) L x mol(-1) respectively. The thermodynamic parameters showed that the interaction between catechin and BSA was driven mainly by hydrophobic force and electrostatic interaction. The displacement experiment shows that catechin can bind to the site I of BSA. The distance between the 214 tryptophan residues in BSA and catechin was estimated to be 1.46 nm using Foster's equation on the basis of fluorescence energy transfer. According to FTIR, the secondary structure of BSA changed when catechin was added.

Aqua[N-(2,5-dihydroxybenzyl)imino-diacetato]copper(II).

The title complex, [Cu(C(11)H(11)NO(6))(H(2)O)], contains a Cu(II) atom in a distorted square-pyramidal geometry. The metal centre is coordinated in the basal sites by one water mol-ecule and two carboxyl-ate O atoms and one N atom of the tetra-dentate ligand [Cu-O range, 1.9376 (11)-1.9541 (12), Cu-N, 1.9929 (12) Å] while the apical site is occupied by a hydro-quinone O donor atom [Cu-O, 2.3746 (12) Å]. Inter-molecular hydrogen bonding inter-actions involving both hydro-quinone hydr-oxy groups and the coordinated water as donors give a three-dimensional framework structure.

{N,N-Dimethyl-N'-[phen-yl(2-pyrid-yl)methyl-ene]ethane-1,2-diamine-κN,N',N''}dithio-cyanato-κN,κS-copper(II).

In the title complex, [Cu(NCS)(2)(C(16)H(19)N(3))], the Cu(II) atom is coordinated by a total of four N atoms; three from one tridentate Schiff base ligand and one from one of the NCS(-) ions. The S atom from the other NCS(-) ion completes the distorted square-pyramidal coordination.

The first mu3-oxalato-bridged copper complex with tridentate Schiff base ligand N-ethyl-N'-salicylidene-1,2-diaminoethane: synthesis, structure, and magnetic properties.

The first mu(3)-oxalato-bridged copper(II) complex, [[Cu(3)(L)(3)(mu(3)-C(2)O(4))][Cu(L)(H(2)O)](ClO(4))(2)] x 0.5(H(2)O) x 0.5(CH(3)OH), where HL = N-ethyl-N'-salicylidene-1,2-diaminoethane, has been synthesized and characterized by variable-temperature magnetic susceptibility measurement. The complex exhibits ferromagnetic coupling between the oxalato-bridged copper atoms and antiferromagnetic coupling between the oxygen-bridged copper atoms.