Nickel is absorbed mainly through the lungs and gastrointestinal tract. Once in the body it enters the bloodstream, where it binds to albumin, L-histidine, and _2-macroglobulin. Nickel tends to accumulate in the lungs, thyroid, kidney, heart, and liver. Absorbed nickel is excreted in the urine, wherease unabsorbed nickel is excreted in the faeces. (L41)
... Nickel carbonate is insoluble in water. ... Respiratory absorption with secondary gastrointestinal absorption of nickel (insoluble compounds) is the major route of entry during occupational exposure. A significant quantity of inhaled material is swallowed following mucocillary clearance from the respiratory tract. Poor personal hygiene & work practices can contribute to gastrointestinal exposure. Percutaneous absorption is negligible, quanitatively, but is important in the pathogenesis of contact hypersensitivity. Absorption is related to the solubility of the compound /& nickel carbonate is classified as an insoluble salt/. Nickel carbonate ... induced local mesenchymal tumors in a variety of experimental animals after im, sc, ip, intrapleural, intraocular, intraosseous, intrarenal, intra-articular, intratesticular or intra-adipose administration.
Nickel is known to substitute for other essential elements in certain enzmes, such as calcineurin. It is genotoxic, and some nickel compounds have been shown to promote cell proliferation. Nickel has a high affinity for chromatin proteins, particularly histones and protamines. The complexing of nickel ions with heterochromatin results in a number of alterations including condensation, DNA hypermethylation, gene silencing, and inhibition of histone acetylation, which have been shown to disturb gene expression. Nickel has also been shown to alter several transcription factors, including hypoxia-inducible transcription factor, activating transcription factor, and NF-KB transcription factor. There is also evidence that nickel ions inhibit DNA repair, either by directly inhibiting DNA repair enzymes or competing with zinc ions for binding to zinc-finger DNA binding proteins, resulting in structural changes in DNA that prevent repair enzymes from binding. Nickel ions can also complex with a number of cellular ligands including amino acids, peptides, and proteins resulting in the generation of oxygen radicals, which induce base damage, DNA strand breaks, and DNA protein crosslinks. (L41, A40)
Evaluation: There is sufficient evidence in humans for the carcinogenicity of nickel sulfate, and of the combinations of nickel sulfides and oxides encountered in the nickel refining industry. There is inadequate evidence in humans for the carcinogenicity of metallic nickel and nickel alloys. There is sufficient evidence in experimental animals for the carcinogenicity of metallic nickel, nickel monoxides, nickel hydroxides and crystalline nickel sulfides. There is limited evidence in experimental animals for the carcinogenicity of nickel alloys, nickelocene, nickel carbonyl, nickel salts, nickel arsenides, nickel antimonide, nickel selenides and nickel telluride. There is inadequate evidence in experimental animals for the carcinogenicity of nickel trioxide, amorphous nickel sulfide and nickel titanate. The Working Group made the overall evaluation on nickel compounds as a group on the basis of the combined results of epidemiological studies, carcinogenicity studies in experimental animals, and several types of other relevant data, supported by the underlying concept that nickel compounds can generate nickel ions at critical sites in their target cells. Overall evaluation: Nickel compounds are carcinogenic to humans (Group 1). Metallic nickel is possibly carcinogenic to humans (Group 2B). /Nickel compounds/
NICKEL CARBONATE WAS GIVEN INTRATRACHEALLY TO MICE (0.05 MG) & URINARY EXCRETION & LUNG CLEARANCE OF NICKEL DETERMINED 1-6 DAYS FOLLOWING ADMIN. MORE NICKEL EXCRETED IN URINE DURING 1ST DAY THAN REMAINDER OF WK. CLEARANCE OF NICKEL CARBONATE FROM LUNG WAS MODERATE.
利用原位X射线粉末衍射和透射电子显微镜研究了氧化镍形态对CO / H 2环境中活化过程中结构转变机理的影响。发现在初始反应阶段,氧化镍结构以两种方式转变:(i)通过形成Ni / NiO体系将NiO还原为Ni;(ii)随着Ni 3 C / NiO催化剂的发展而使NiO碳化。已经显示出特定的相变取决于母体氧化物的晶格与所得产物之间的结构相似性。所得数据表明NiO与CO / H 2的相互作用反应混合物是结构敏感的反应。还讨论了一氧化碳在两种拓扑化学过程中的作用。
Cation Distribution and Local Configuration of Fe2+ Ions in Structurally Nonequivalent Lattice Sites of Heterometallic Fe(II)/M(II) (M = Mn, Co, Ni, Cu, Zn) Diaquadiformato Complexes
作者:M. Devillers、J. Ladrière
DOI:10.1006/jssc.1993.1092
日期:1993.3
57Fe Mössbauer investigations are carried out on a wide series of heterometallic diaquadiformato Fe(II)/M(II) complexes with M = Mn, Co, Ni, Cu, and Zn to provide a local picture of the coordination environment of the 57Fe2+ ions as a function of (i) the nature of the host cation and (ii) the relative amounts of both metals in the matrix (between 50 and 0.25 at.% Fe). Information is obtained on the
deprotonated. For the Co precursor the formate and phosphates ions are randomly coordinated to both Co and Li cations, whereas for the Ni precursor there is a preferential coordination of the formate and phosphate ions around the Ni 2+ and Li + ion, respectively. Thermal treatment of the precursors yields single phases of olivine-type LiCoPO 4 at 450 °C and LiNiP0 4 at 700 °C. Structural analysis evidences
橄榄石型LiCoPO 4 和LiNiPO 4 的单相是通过对均相锂金属磷酸盐甲酸盐前体进行热处理合成的,该前体是通过冷冻干燥相应金属甲酸盐和LiH 2 PO 4 的水溶液而获得的。通过红外光谱、DTA 和 SEM 研究了前驱体的结构、热行为和形貌。钴和镍磷酸甲酸前体的组成为 LiMH x (PO 4 )(HCOO) x ·yH 2 O,其中甲酸和磷酸基团主要去质子化。对于 Co 前驱体,甲酸根离子和磷酸根离子与 Co 和 Li 阳离子随机配位,而对于 Ni 前驱体,甲酸根和磷酸根离子分别优先配位在 Ni 2+ 和 Li + 离子周围。前体的热处理在 450°C 下产生橄榄石型 LiCoPO 4 和在 700°C 下的 LiNiPO 4 单相。结构分析表明,LiCoPO 4 和LiNiPO 4 都具有有序的橄榄石型结构,在金属位置和锂缺乏之间没有任何Li到M的紊乱。已经讨论了冻干溶液浓度和退火温度对LiCoPO
Reactions of methyl fluorosulphate and triethyloxonium tetrafluoroborate with transition-metal complexes
作者:Colin Eaborn、Nicholas Farrell、James L. Murphy、Alan Pidcock
DOI:10.1039/dt9760000058
日期:——
Reactions of SFO2(OMe) and [Et3O][BF4] with a variety of transition-metalcomplexes have been examined and classified as ligand abstraction, oxidative additions, oxidation, ligand alkylation, or reactions in which an anion fragment is abstracted from a ligand. Factors influencing the mode of reaction and the mechanisms of some of the reactions are discussed.
New mixed-ligands complexes with empirical formulae: M(2,4′-bpy)2L2·H2O (M(II)Zn, Cd), Zn(2-bpy)3L2·4H2O, Cd(2-bpy)2L2·3H2O, M(phen)L2·2H2O (where M(II)=Mn, Ni, Zn, Cd; 2,4′-bpy=2,4′-bipyridine, 2-bpy=2,2′-bipyridine, phen=1,10-phenanthroline, L=HCOO−) were prepared in pure solid state. They were characterized by chemical, thermal and X-ray powder diffraction analysis, IR spectroscopy, molar conductance in MeOH, DMF and DMSO. Examinations of OCO− absorption bands suggest versatile coordination behaviour of obtained complexes. The 2,4′-bpy acts as monodentate ligand; 2-bpy and phen as chelating ligands. Thermal studies were performed in static air atmosphere. When the temperature raised the dehydration processes started. The final decomposition products, namely MO (Ni, Zn, Cd) and Mn3O4, were identified by X-ray diffraction.
divalent metal determines the occurrence of antiferromagnetic ordering below 30 K opening the avenue for a rational formulation of a new class of multiferroic materials. We demonstrate that this intriguing class of compounds can be synthetized with a mechanochemical approach. This novel route of synthesis was applied to the series [NH4][M(HCOO)3] with M= Cu2+, Co2+, Mn2+, Zn2+ and Ni2+ using as reactants ammonium
具有式[NH 4 ][M(HCOO) 3 ]的化合物家族,其中M为二价d-金属,其特征在于承载NH 4 +阳离子的多孔骨架在低温下表现出自发的铁电极化。磁性活性二价金属的存在决定了低于 30 K 的反铁磁有序的发生,为合理配方的新型多铁性材料开辟了道路。我们证明了这一类有趣的化合物可以用机械化学方法合成。这种新的合成路线应用于 [NH 4 ][M(HCOO) 3 ] 系列,其中 M= Cu 2+ , Co 2+ , Mn2+、Zn 2+和Ni 2+使用甲酸铵和相应的二水合金属甲酸盐作为反应物。该过程的研磨持续时间与二水合金属甲酸盐的热稳定性相关,表明机械合成过程的第一步是去除水分子。最终产品的特征表明存在具有极好结晶度的单相[NH 4 ][M(HCOO) 3 ]化合物。