二价铜、镍EDTA络合物晶体的电子吸收光谱

络合物晶体的电子吸收光谱作为研究晶体的电子结构的基础内容,很早以前就得到人们注意,虽然对Cu~(2+)、Ni~(2+)等络合物电子光谱的能级的经验指认已是一项较为成熟的工作,但对吸收光谱的系统的理论计算和定量解释在以前的文献中尚不多见.近年来,我们对多种晶体的电子吸收光谱进行了定量的解释,结果表明理论计算值总是能很好地符合于实验测定值。一般说来,吸收峰位的波数误差在8%以内. 早在本世纪四十年代就奠定了乙二胺四乙酸(EDTA)在分析化学中的应用基础。     

Thermal decomposition study on nickel(ii) complexes of 1,2-(diimino-4’-antipyrinyl)ethane with varying counter ions

The phenomenological, kinetic and mechanistic aspects of the nitrate, chloride, bromide and iodide complexes of nickel(II) with1,2-(diimino-4’-antipyrinyl)ethane (GA) have been studied by TG and DTG techniques. The kinetic parameters like activation energy, pre-exponential factor and entropy of activation were computed. The rate controlling process in all stages of decomposition is random nucleation with one nucleus on each particle (Mampel model).     

Ion Association and Hydration in Aqueous Solutions of Nickel(II) and Cobalt(II) Sulfate

Aqueous solutions of nickel(II) and cobalt(II) sulfate have been investigated at 25 ^∘C by dielectric relaxation spectroscopy (DRS) over a wide range of frequencies (0.2 ≤ ν (GHz) ≤ 89) and salt concentrations (0.025 ≤ c(mol-L⁻¹) ≤ 1.4). The spectra indicate, as for MgSO₄(aq) studied previously, the simultaneous presence of double solvent-separated, solvent-shared and contact ion pairs in both NiSO₄(aq) and CoSO₄(aq). The stepwise formation constants for each ion-pair type and the overall association constant, obtained from the data are in good agreement with ultrasonic relaxation and other estimates. The DR spectra at higher concentrations (c ≥ 0.5 mol-L⁻¹) suggest the existence of a nonlinear triple ion M₂SO₄²⁺(aq). Consistent with the very strong hydration of the salts, which have ‘effective’ hydration numbers approaching 27 at infinite dilution, there are no significant differences in any of the relaxation or thermodynamic parameters for NiSO₄(aq) and CoSO₄(aq), except that the triple ion appears to be somewhat more stable for the latter.     

Thermochemische Untersuchungen zu den Systemen Ti/Ni und Ti/Co

Thermochemical Investigations of the Systems Ti/Ni and Ti/Co By treatment of solid Ni or Co with a H₂/TiCl₄-gas mixture at sufficient high temperature (T ≥ 900°C) the intermetallic phases TiNi₃ and TiCo₃, resp., are formed. The conversion grade depends on the H₂/TiCl₄-ratio. From the experimentally determined conversion grades and the known thermodynamic data of all other species existing in equilibrium the free enthalpies and the heats of formation of TiN₃ and TiCo₃ have been calculated (TiNi₃: ΔH(298) = ?133.3 ± 6 kJ/mol; TiCo₃: ΔH(298) = ?104.7 ± 6 kJ/mol).     

在吡啶溶剂中氯化镍催化的溴代芳烃自身偶联反应

Pyridine was used as a solvent for homocoupling of aryl bromides catalyzed by nickel chloride/triarylphosphinein the presence of zinc and recycled easily.Triphenylphosphine was the best ligand for nickel in this coupling reac-tion.     

Influence of conjugated nitrogenous bases on the spectra and structure of mixed-ligand nickel(II) chelates containing β-diones

The infrared and electronic excitation spectra of a series of new nickel(II) chelates containing an-diimine (or nitrogenous base, enR) and the anion of a-dione (1,3-ketoenol or 1,3-ketoester,H) were obtained in the solid state and in solution. The composition and the overall structure of the new chelates in the solid state depends on ligand concentration, the substituents within the-dionato moiety and the counterion present. The IR and electronic excitation spectra of [Ni(enR)₂ ]NO₃ and [Ni(enR)(O₂NO)] indicate, in conjunction with other physicochemical measurements, bidentate coordination of the ligands, while the spectral shifts reveal replacement of the (O,O)nitrato group by basic solvents. The existence of the nickel(II) in an octahedral environment is confirmed by an X-ray structure analysis of [Ni(dpamH)₂acac]NO₃ · CH₃OH (monoclinic, space groupP2_l/n, a=17.296(1),b=7.462(1),c=21.604(3) å,=95.65(1),Z=4, R=0.0534,Rw=0.0600), where dpamH denotes the 2,2-dipyridylamine.     

超声波处理对球形β-Ni(OH)2结构及电化学性能的影响

A method of ultrasonic treatment （UST） was first used to modify the structure and electrochemical performance of nickel hydroxide for the active material of nickel series alkaline batteries. The experimental results showed that UST was an effective method to improve the electrochemical performance of β-Ni（OH）2 such as specific discharge capacity, discharge potential, electrochemical reversibility and oxygen evolution over-potential. The results of electrochemical impedance spectroscopy, powder X-ray diffraction and particle size distribution indicated that the improvement of the performance of β-Ni（OH）2 through UST was attributed to the reduction of the charge-transfer resistance （Rt） and the diffusion impedance （Zw）, which resulted from the decrease of the crystallite and particle size and the increase of interlayer spacing. Diffusion coefficient of proton DH of ultrasonic treated β-Ni（OH）2 gained by CV tests was 1.13 × 10^-11 cm^2/s, and the average discharge specific capacity of ultrasonic treated β-Ni（OH）2 electrode was 301 mAh/g.     

化学镀非晶态Ni—P层的初期沉积过程研究

化学镀非晶态Ｎｉ－Ｐ镀层初期沉积过程和沉积层状态是影响结合强度的决定性因素．对不同基体材料初期沉积的观察发现，有些非晶态镀层的初期沉积中含有微晶．微晶的产生与否与基体材料以及镀层材料晶格的错配度有关，当镀层与基体材料点阵常数相差不大，镀层的初期沉积沿基体晶格外延生长出现微晶层，反之，点阵常数相差较大时，初期沉积物中未发现微晶．     

曲率流的参数化有限元逼近

许多物理现象可以在数学上描述为受曲率驱动的自由界面运动,例如薄膜和泡沫的演变、晶体生长,等等.这些薄膜和界面的运动常依赖于其表面曲率,从而可以用相应的曲率流来描述,其相关自由界面问题的数值计算和误差分析一直是计算数学领域中的难点.参数化有限元法是曲率流的一类有效计算方法,已经能够成功模拟一些曲面在几类基本的曲率流下的演化过程.本文重点讨论曲率流的参数化有限元逼近,它的产生、发展和当前的一些挑战.     

Aryl-bis(triorganylphosphine)nickel phenoxides

Compounds of general formulatrans-ArNi(PR₃)₂OAr' (R = Et, cyclohexyl; Ar = 2-MeC₆H₄, 2-FC₆H₄; Ar' = 4-FC₆H₄, 4-NO₂C₆H₄) were synthesized by the reaction of Ar'OK with cationic nickel complexes generated by treatment of ArNi(PR₃)₂Cl with TlBF₄. Syntheses of 4-fluorophenoxide complexes, ArNi(PR₃)₂OC₆H₄F-4, additionally give some quantities oftrans-[ArNi(PR₃)₂OC₆H₄F-4][HOC₆H₄F-4] adducts. Exchange reactions MeC₆H₄Ni(PEt₃)₂OC₆H₄F-4 + XC₆H₄OH 2-MeC₆H₄Ni(PEt₃)₂OC₆H₄X + 4-FC₆H₄OH were studied in THF. The equilibrium is shifted to the right as the acidity of ArOH increases. A linear relationship between lgK _eq and pK _a of XC₆H₄OH in DMSO was found. A conclusion concerning the strong polarization of the Ni-O bond was made on the basis of an analysis of the chemical shifts of fluorine atoms in 2-MeC₆H₄Ni(PEt₃)₂OC₆H₄F-4.Translated fromIvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2266–2271, November, 1995.