Highly efficient polymer‐stabilized palladium heterogeneous catalyst: Synthesis,characterization and application for Suzuki–Miyaura and Mizoroki–Heck coupling reactions

A suitable approach to stabilize palladium nanoparticles (Pd NPs), with an average diameter of 3–4 nm, on magnetic polymer is described. A new magnetic polymer containing 4′‐(4‐hydroxyphenyl)‐2,2′:6′,2″‐terpyridine (HPTPy) ligand was prepared by the polymerization of itaconic acid (ITC) as a monomer and trimethylolpropane triacrylate (TMPTA) as a cross‐linker and fully characterized. Pd NPs embedded on the magnetic polymer were successfully applied in Suzuki–Miyaura and Mizoroki–Heck coupling reactions under low palladium loading conditions, and provided the corresponding products with excellent yields (up to 98%) and high catalytic activities (TOF up to 257 hr^?1). Also, the catalyst can be easily separated and reused for at least consecutive five times with a small drop in catalytic activity.     

A new strategy to design a graphene oxide supported palladium complex as a new heterogeneous nanocatalyst and application in carbon–carbon and carbon‐heteroatom cross‐coupling reactions

The palladium nanoparticles were successfully stabilized with an average diameter of 6–7 nm through the coordination of palladium and terpyridine‐based ligands grafted on graphene oxide surface. The graphene oxide supported palladium nanoparticles were thoroughly characterized and applied as an efficient heterogeneous catalyst in carbon–carbon (Suzuki‐Miyaura, Mizoroki‐Heck coupling reactions) and carbon–heteroatom (C‐N and C‐O) bond‐forming reactions. The catalyst was simply recycled from the reaction mixture and was reused consecutive four times with small drop in catalytic activity.     

Fluorescent zinc-terpyridine complex containing coordinated peroxo counter ion in aqueous medium

We describe a mixed ligand-zinc(d ¹⁰ ) complex containing coordinated peroxo ion and 2,2′2″-terpyridine and exhibiting fluorescence in the visible region (473 nm) on excitation at 390 nm in aqueous medium at room temperature. We also discuss the unusual phenomenon of enhancement of this fluorescence intensity on addition of some transition metal ions(3d ⁵, 3d¹⁰, 4d⁰and3d ⁹electronic configurations).     

三联吡啶铂(Ⅱ)配合物光谱性质的密度泛函研究

采用密度泛函理论方法(DFT),对三联吡啶铂(Ⅱ)配合物的结构与电子光谱进行了系统研究.筛选的PBE/LanL2DZ(6-311+G(d))—BMK/LanL2DZ(6-31+G(d))方法,计算结果能较好地与实验值吻合:对光谱峰波长的计算,吸收光谱和发射光谱平均误差分别为14 nm和17 nm.通过对前线分子轨道的分析,归属了各光谱峰的跃迁类型.计算结果表明,不同推拉电子效应的取代基对配合物光谱峰的位置和跃迁类型具有较大影响,为已有的实验结论提供了有力的理论阐述.     

Synthesis,characterization and cytotoxicity of Pt(II), Pd(II), Cu(II) and Zn(II) complexes with 4’‐substituted terpyridine

Eight novel Pt(II), Pd(II), Cu(II) and Zn(II) complexes with 4’‐substituted terpyridine were synthesized and characterized by elemental analysis, UV, IR, NMR, electron paramagnetic resonance, high‐resolution mass spectrometry and molar conductivity measurements. The cytotoxicity of these complexes against HL‐60, BGC‐823, KB and Bel‐7402 cell lines was evaluated by MTT assay. All the complexes displayed cytotoxicity with low IC₅₀ values (<20 μm ) and showed selectivity. Complexes 3 , 5 , 7 and 8 exerted 9‐, 5‐, 12‐ and 7‐fold higher cytotoxicity than cisplatin against Bel‐7402 cell line. The cytotoxicity of complexes 3 , 5 , 6 , 7 and 8 was higher than that of cisplatin against BGC‐823 cell line. Complexes 3 , 7 and 8 showed similar cytotoxicity to cisplatin against KB cell line. Complex 7 exhibited higher cytotoxicity than cisplatin against HL‐60 cell line. Among these complexes, complex 7 demonstrated the highest in vitro cytotoxicity, with IC₅₀ values of 1.62, 3.59, 2.28 and 0.63 μm against HL‐60, BGC‐823, Bel‐7402 and KB cells lines, respectively. The results suggest that the cytotoxicity of these complexes is related to the nature of the terminal group of the ligand, the metal center and the leaving groups. Copyright © 2013 John Wiley & Sons, Ltd.     

Immobilization of Ru(terpyridine)(2,6‐pyridinedicarboxylate) onto MCM‐41 and its catalysis in the oxidation of alcohols

The ruthenium complex Ru(terpyridine)(2,6‐pyridinedicarboxylate) was successfully grafted onto MCM‐41 using a multi‐step grafting method. The immobilized ruthenium complex was characterized thoroughly using Fourier transform infrared, Raman, UV–visible diffuse reflectance and energy‐dispersive X‐ray spectroscopies, X‐ray diffraction, N₂ adsorption, scanning electron microscopy, thermogravimetric analysis and inductively coupled plasma analysis. This immobilized ruthenium complex showed excellent performance in the oxidation of various secondary alcohols to their corresponding ketones with tert‐butyl hydroperoxide as oxidant under solvent‐free conditions, and had the advantages of easy recovery and good reusability. Copyright © 2016 John Wiley & Sons, Ltd.     

Further Determination of Cadmium Ions in Water by an Electrochemiluminescence Method

ABSTRACT

Two new electrochemiluminescence (ECL) reactions in aqueous solution involving cadmium(II) ions are reported. The ECL reaction occurs in the presence of a common co-reactant, tripropylamine (TPA), and either of two organic ligands, 2,2′:6′,2″-terpyridine or 2,2′-bipyridine. The reaction is presumed to arise from the metal-ligand complex and the co-reactant. Conditions for ECL emission were optimised and a calibration graph constructed. Emission was linear over the range 10-1 000 ppb. The calculated limits of detection (LOD) were 8 and 50 ppb using terpyridine and bipyridine, respectively. Comparison with a previously reported reaction involving cadmium(II) ions and 1, 10-phenathroline is made.     

Structural studies and cytotoxic activity of a new dinuclear coordination compound of palladium(II)–2,2′:6′,2″‐terpyridine with rigid dianionic 1,2,4‐triazole‐3‐sulfonate linker

A new dinuclear coordination compound of palladium(II), [Pd₂(terpy)₂(μ‐tas‐N¹,N⁴)]SO₄?11H₂O ( 1 ), was synthesized by tethering a doubly deprotonated 1,2,4‐triazole‐3‐sulfonate (tas) linker generated in situ via oxidation of 1,2,4‐triazole‐3‐thione (tat) under the synthetic conditions. X‐ray diffraction analysis reveals that tat molecules adopt the thione form in the solid state, and are combined in infinite chains by symmetrically related classical intermolecular hydrogen bonds N1─H1???S1, N3─H3???N2 to give rise to R₂²(7) pattern in one‐dimensional chains along the b‐axis propagating along the a‐axis. Further short contacts through lone pairs of N2???S1 on the rings between the adjacent chains along the a‐axis lead to a two‐dimensional network structure. Compound 1 was characterized using infrared, ¹H NMR and UV–visible spectroscopies, electrospray ionization mass spectrometry and X‐ray crystallography. The crystal structure determination of 1 reveals that the Pd(II) ions are coordinated with four nitrogen atoms: three from terpy and one from tas acting as an end‐to‐end (μ‐1,4) bridging ligand. The Pd(II) ions in 1 adopt a distorted square planar geometry. The anti‐growth effect of 1 was tested on colorectal cancer (HCT‐15), non‐small‐cell lung cancer (A549), prostate cancer (PC‐3) and cervical cancer (HeLa) cell lines using sulforhodamine B viability assay. The cytotoxic effect was further confirmed using adenosine triphosphate viability assay. Compound 1 shows a promising cytotoxic activity in the diverse cancer cell models in vitro (p <0.0001).