Ein neues Erdalkalimetall-Oxoplatinat-Cuprat Ca3,5Cu0,5PtO6

A new Alkaline-Earth Platinum Copper Oxide: Ca_3.5Cu_0.5PtO₆ Ca_3.5Cu_0.5PtO₆ was prepared and investigated by single crystal X-ray work. (Space group C? C12/m1; a = 9.0743; b = 9.2527; c = 6.4840 Å; β = 91.448°; Z = 4). The crystal structure of the previously unknown compound is closely related to the structure of Sr₃PtCuO₆ and Sr₃IrCuO₆ as well as the rhombohedral phases M₄PtO₆ (M = Ba, Sr, Ca). Typical features of the crystal chemistry are isolated chains of PtO₆ octahedra, alternately allyed by square CuO₄ polygones and trigonal prisms of O^2? around Ca²⁺.     

Electroless preparation and electrochemical behavior of a platinum-doped nickel hexacyanoferrate film–zinc modified electrode: catalytic ability of the electrode for electrooxidation of methanol

The use of a zinc substrate as an electrode and the modification of its surface by means of a thin film of platinum-doped nickel hexacyanoferrate (Pt-NiHCF) were developed. The modification conditions of the zinc surface including the electroless deposition of metallic nickel on the electrode surface from NiCl₂ solution, chemical derivatization of the deposited nickel to the NiHCF film in 0.5 M K₃[Fe(CN)₆] solution, and electrochemical penetration of metallic platinum into the modified film are described. The modified zinc electrodes prepared under optimum conditions show a well-defined redox couple due to the [Ni^IIFe^III/II(CN)₆]^1–/2– system. The effects of pH, the alkali metal cation, and the anion of the supporting electrolyte on the electrochemical characteristics of the modified electrode were studied in detail. The diffusion coefficients of hydrated alkali metal cations in the film (D), the transfer coefficient (), and the transfer rate constant for the electron (k_s) were calculated in the presence of some alkali metal cations. The electrocatalytic activity of the modified electrode for methanol oxidation was demonstrated. The stability of the modified electrode under various experimental conditions was investigated.     

一种N-酰肌氨酸在四氧化三铁纳米颗粒表面的吸附特征

根据表面活性剂固液界面吸附理论和表面改性颗粒亲水疏水特性及红外光谱分析,提出了不同四条件和表面活性剂用量下不同的吸附模型。     

Preconcentration and Separation Procedures for the Spectrochemical Determination of Platinum and Palladium

Low concentrations of Pt and Pd in industrial (µgg^–1 level) and environmental samples (ngg^–1 level) together with the complexity of the matrix causing many interferences during the determination of noble metals often require elaboration and application of pre-concentration/matrix separation procedures before detection of the analyte. Different pre-concentration/matrix separation procedures applied prior to the determination of Pt and Pd by atomic spectrometric techniques are reviewed and critically compared taking into account potential interferences. The methods studied are divided into 5 groups including precipitation and coprecipitation, liquid–liquid extraction, solid phase extraction, electrochemical pre-concentration and biosorption. The main analytical problems occuring during sample preparation and storage are discussed.     

Studies of poly-<Emphasis Type="Italic">L</Emphasis>-lysine-starch nanoparticle preparation and its application as gene carrier

Anion starch nanoparticle (StNP) with a diameter of 50 nm was prepared in water-in-oil microemulsion, with soluble starch as raw materials and POCl₃ as crosslinking agent. PLL-StNP was prepared by linking poly-L-lysine (PLL) on the surface of StNP. At the same time, the size of PLL-StNP and its stability in aqueous solution were checked by AFM. The analysis of plasmid DNA binding, DNase I enzymatic degradation, toxicity and transfection were done. We discovered that PLL-StNP may be used as non-virus nanoparticle gene carrier. And we developed the method of preparing PLL-StNP gene carrier and used it in cell transfection. As non-virus gene carrier, PLL-StNP has some advantages, such as large load of DNA, high transfection efficiency, low cell toxicity and biodegradability.     

Mononuclear Pt(II) and Pd(II) 1,4-dithiolato complexes. Crystal structures of [Pt((−) DIOS) (PPh3)2] and [Pd(S(CH2) 4S)(Ph2P(CH2) 3PPh2)]. Application in styrene hydroformylation

Addition of 1,4-dithiols to dichloromethane solutions of [PtCl₂(P-P)] (P-P = (PPh₃)₂, Ph₂P(CH₂)₃PPh₂, Phd₂P(CH₂)₄PPh₂; 1,4-dithiols = HS(CH₂)₄SH, (−)DIOSH₂ (2,3-O-isopropylidene-1,4-dithiol-l-threitol), BINASH₂ (1,1′-dinaphthalene-2,2′-dithiol)) in the presence of NEt₃ yielded the mononuclear complexes [Pt(1,4-dithiolato)(P-P)]. Related palladium(II) complexes [Pd(dithiolato)(P-P)] (P-P=Ph₂P(CH₂)₃PPh₂, Ph₂P(CH₂)₄PPh₂; dithiolato = ⁻S(CH₂)₄S⁻, (−)-DIOS) were prepared by the same method. The structure of [Pt((−)DIOS)(PPh₃)₂] and [Pd(S(CH₂)₄S)(Ph₂P(CH₂)₃PPh₂)] complexes was determined by X-ray diffraction methods. Pt—dithiolato—SnC1₂ systems are active in the hydroformylation of styrene. At 100 atm and 125°C [Pt(dithiolate)(P-P)]/SnCl₂ (Pt:Sn = 20) systems provided aldehyde conversion up to 80%.     

The preparation of a new polysiloxane copolymer with glucosylthioureylene groups on the side chains

A new polysiloxane with pendent sugar units was prepared by a two-step method: the preparation of the polysiloxane with amino groups on the side chain and then the copolysiloxane reacted with glucosyl isothiocyanate. All polymers were characterized by FT-IR 1H-NMR, 1H-1H-COSY, 13C-NMR, and DEPT respectively. In the same time, Platinum oxide was found to be a versatile and powerful hydrosilation catalyst in the hydrosilylation reaction of aminotrimethylenepolysiloxanes with heptamethylcyclotetrasiloxane (D₄^H).     

Synthesis and characterization of platinum(II) and (IV) complexes containing hexamethyleneimine ligand: crystal structure of [Pt(hexamethyleneimine)2(cyclobutanedicarboxylato)]·H2O

A series of new platinum(II) and platinum(IV) complexes of the type [Pt^II(HMI)₂X] (where HMI=hexamethyleneimine, X=dichloro, sulfato, 1,1-cyclobutanedicarboxylato [CBDCA], oxalato, methylmalonato, or tatronato) and [Pt^IV(HMI)₂Y₂Cl₂] (where Y=hydroxo, acetato, or chloro) were synthesized and characterized by infrared (IR) spectroscopy, ¹³C and ¹⁹⁵Pt nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. Among the complexes synthesized, [Pt^II(hexamethyleneimine)₂(1,1-cyclobutanedicarboxylato)]·H₂O was examined by single-crystal X-ray diffraction. The slightly distorted square planar coordination environment of the platinum metal includes the amino group of the hexamethyleneimine (HMI) molecule and the oxygen atoms of the carboxylato ligand. The cyclobutanedicarboxylic acid (CBDCA) molecule adopts six-member chelating rings with platinum. Hydrogen bonding plays an important part in holding the crystal lattice together.     

Synthese und Struktur der Platin(O)-Verbindungen [(dipb)Pt]2(COD) und (dipb)3Pt2 sowie des clusters Hg6[Pt(dipb)]4 (dipb = (i-Pr)2P(CH2)4P(i-Pr)2)

Synthesis and Structure of the Platinum(0) Compounds [(dipb)Pt]₂(COD) and (dipb)₃Pt₂ and of the Cluster Hg₆[Pt(dipb)]₄ (dipb = (i-Pr)₂P(CH₂)₄P(i-Pr)₂) The reduction of (dipb)PtCl₂ with Na/Hg yields (dipb)Pt as an intermediate which reacts with the amalgam to form the cluster Hg₆[Pt(dipb)]₄ ( 3 ) or decomposes to (dipb)₃Pt₂ ( 2 ) and Pt. In the presence of COD [(dipb)Pt]₂(COD) ( 1 ) is obtained. 1 crystallizes monoclinicly in the space group P2₁/c with a = 1596.1(4), b = 996.5(2), c = 1550.4(3) pm, β = 113.65(2)°, Z = 2. In the dinuclear complex two (dipb)Pt units are bridged by a 1,2-η²-5,6-η² bonded COD ligand. Whereby the C = C double bonds are lengthened to 145 pm. 2 forms triclinic crystals with the space group P1 and a = 1002.0(2), b = 1635.9(3), c = 868.2(2) pm, α = 94.70(2)°, β = 94.45(2)°, σ = 87.95(1)°, Z = 1. In 2 two (dipb)Pt moieties are connected by a μ-dipb ligand in a centrosymmetrical arrangement. 3 is monoclinic with the space group C2/c and a = 1273.8(3), b = 4869.2(6), c = 1660.2(3) pm, β = 95.16(2)°, Z = 4. The clusters Hg₆[Pt(dipb)]₄ have the symmetry C₂. Central unit is a Hg₆ octahedron of which four faces are occupied by Pt(dipb) groups. The bonding in the cluster is discussed on the basis of eight Pt? Hg two center bonds of 267.6 pm and two Pt? Hg? Pt three center bonds with Pt? Hg = 288.0 pm.     

Syntheses, spectroscopic characteristics and thermolytic rearrangements of bis-[(trimethylgermyl)methyl]platinum(II) and bis-[(trimethylstannyl)methyl]platinum(II) complexes

The preparations and spectroscopic characteristics are reported of a series of (trimethylgermyl)methyl- and (trimethylstannyl)methylplatinum(II) complexes with diene and P-donor ancillary ligands, cis-Pt(CH₂GeMe₃)₂L₂ (L = PPh₃ or PPh₂Me; L₂ = dppe or cod) and cis-Pt(CH₂SnMe₃)₂L₂ (L = PPh₃; L₂ =cod). Thermolysis of toluene solutions of cis-Pt(CH₂GeMe₃)₂(PPh₃)₂ leads to cis-Pt(Me)(CH₂GeMe₂CH₂GeMe₃)(PPh₃)₂ via β-alkyl migration, after (non-rate-limiting) phosphine dissociation. Estimated activation parameters (ΔH_{298 K}^‡ = 126 ± 3 kJ mol⁻¹, ΔS^‡ = + 17 ± 7 J mol⁻¹ K⁻¹ and hence Δ_{298 K}^‡ = 121 ± 5 kJ mol⁻¹) suggest that this system is more migration labile than its silicon analogue, primarily as a result of a lower activation enthalpy. While cis-Pt(CH₂GeMe₃)₂(PPh₂Me)₂ reacts similarly but less readily, Pt(CH₂GeMe₃)₂(dppe)₂ is inert at operable temperatures. Thermolysis of Pt(CH₂GeMe₃)₂(cod) generates 1,1,3,3,-tetramethyldi-1,3-germacyclobutane as the major organogermanium product, while from cis-Pt(CH₂SnMe₃)₂(PPh₃)₂, 1,1,3,3-tetramethyldi-1,3-stannacyclobutane predominates. Mechanistic implications are discussed.