共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Transition metal phosphorus trisulfide compounds with the general formula MPS3, with M = Mn, Fe, Ni, have been prepared by chemical vapor transport, vapor sublimation, and direct combination of the elements. Chemical transport is accomplished by using 75 Torr of chlorine gas as a transport agent and a temperature gradient of 750° → 690°C or 700° → 640°C. The structure of these three compounds, which belongs to the monoclinic space group , is related to that of CdCl2 with a distorted cubic close-packing of the sulfur atoms. Metal atoms and phosphorus-phosphorus pairs occupy the trigonally distorted octahedral holes in a ratio of 2:1 and are ordered throughout the structure. Magnetic susceptibility measurements indicate that all three compounds are antiferromagnetic. The paramagnetic moments indicate that the metal ions in each case exist in the divalent high-spin state. 相似文献
3.
M Roman-Ceba J.C.Avila Roson J Suarez-Varela J.M Salas-Peregrin 《Thermochimica Acta》1984,80(1):115-121
Some new 2,6-xylyliminodiacetato compounds of Mn(II), Fe(III), Ni(III), Zn(II) and Cd(II) have been prepared in aqueous media. The thermal behaviour of these compounds has been studied by TG, DTG, and DSC techniques. Heats of dehydration have been calculated from the DSC curves. 相似文献
4.
5.
The diffusion of some zinc and cobalt salts in water have been measured using an improved version of the capillary technique. In this technique, diffusion proceeds in the absence of stirring in the bulk solution. The amount of diffusing substance which remains in the capillary is analyzed after a chosen time. Nanis' solution for three-dimensional diffusion from a capillary has been used to calculate the experimental values. The values of diffusion coefficient of zinc iodide, cobalt bromide and cobalt iodide have been obtained with a diffusion run time of four hours. A comparison has been made between the experimental and theoretical values obtained from Onsager-Fuoss theory. An attempt has also been made to explain the deviation between the experimental and theoretical values over the concentration range studied. 相似文献
6.
In this contribution a range of photoinduced ligand rearrangements observed for the 1st and 2nd row transition metal and organometallic compounds are discussed. The processes discussed include photoinduced ligand exchange, linkage isomerisation and changes occurring within the coordination sphere of the compounds such as cis–trans and fac–mer isomerisations. The relevance of these processes for photocatalytic cycles or their application as synthetic tools is discussed where appropriate. 相似文献
7.
Mengmeng Zhou Xinjun Huang Xiaomeng Tian Baohua Jia Hongge Pan Wenping Sun Qin Zhao Tianyi Ma 《Journal of Energy Chemistry》2021,(12):195-216
In recent years,a series of aqueous metal ion batteries (AMIBs) has been developed to improve the safety and cost-efficiency of portable electronics and electri... 相似文献
8.
9.
10.
J. Skupińska H. Wilczura H. Boniuk 《Journal of Thermal Analysis and Calorimetry》1986,31(5):1017-1025
Polyacrylales of Fe, Cr, Ni, Co and Mn were synthesized by the reaction of poly(sodium)acrylatc with metal halides. The salts obtained were investigated by thermal analysis. During heating in argon or air, all the salts behaved in a similar way. The initial decomposition temperature of the investigated salts increased in the following sequence: Fe<Cr<Ni<Co<Mn. The solid residues of the decompositions of the salts were also analysed.
Zusammenfassung Polyacrylate von Fe, Cr, Ni, Co und Mn wurden durch Reaktion von Natriumpolyacrylat mit den entsprechenden Metallhaliden synthetisiert. Die erhaltenen Salze wurden thermoanalytisch untersucht. Beim Aufheizen in Argon und Luft verhalten sich alle Salze ähnlich. Die Temperatur, bei der die Zersetzung einsetzt, steigt in folgender Reihenfolge an: Fe < Cr < Ni < Co < Mn. Die festen Rückstände der Zersetzung der Salze wurden ebenfalls analysiert.
, , , . , , . Fe<Cr<Ni<Co<Mn. .相似文献
11.
O. Glemser 《Journal of fluorine chemistry》1984,24(3):319-325
The structures of the solid fluorides MF2, MF3, MF4 and MF5, in which M has the coordination number 6 and belongs to the 3, 4- and 5-periods and the Vb to VIII groups, can be divided into 3 types: (a) cubic close packing () of F with an MFM bridging angle of 180°; (b) hexagonal close packing () with an MFM-bonding angle of 132°; (c) intermediate packing between (a) and (b). The linear bridging is assumed to be a consequence of π-back bonding (or charge transfer) between F-orbitals and -orbitals of the metal. If such bonding is not possible then with the bridging angle of 132° will result. Weaker π-interactions give the intermediates (c). 相似文献
12.
The thermal decompositions of divalent cobalt, cadmium, nickel and copper salicylates and intermediates formed during the decomposition processes were investigated by means of thermogravimetry. Two intermediates were identified in each case, except for copper(II) salicylate.
The authors wish to thank Perkin-Elmer for its collaboration 相似文献
Zusammenfassung Die thermische Zersetzung von divalentem Kobalt-, Cadmium-, Nickel- und Kupfersalicylat und von während der Zersetzungsprozesse gebildeten Zwischenprodukten wurde thermogravimetrisch untersucht. Mit Ausnahme von Kupfer(II)-salicylat konnten in jedem Falle zwei intermediäre Produkte identifiziert werden.
, , , , . , , .
The authors wish to thank Perkin-Elmer for its collaboration 相似文献
13.
The gallane-Lewis base adduct H3Ga·L is employed as a σ-Ga–H ligand for the group 6 carbonyl metal complexes (OC)5M(H3Ga·L) (M = Cr, Mo, W) and the manganese complex Cp*(OC)2Mn(H3Ga·L). Group 6 carbonyl metal derivatives (OC)5M(H3Ga·L) are synthesized by the reaction of (OC)5M(THF) and H3Ga·L. The photochemical reaction of Cp*(OC)3Mn and H3Ga·L affords the gallane manganese σ-complex Cp*(OC)2Mn(H3Ga·L). The structural properties of these complexes can be understood in terms of the coordination mode of σ-Ga–H bond to (OC)5M and Cp*(OC)2Mn fragments being depicted as η1-HGaH2·L and η2-HGaH2·L, respectively. The contribution of σ-donation from the Ga–H σ-bond to dσ orbital on M occurs in both systems, however, the participation of π-back donation from filled dπ orbital to Ga–H σ* orbital is negligible for the (OC)5M(H3Ga·L) complexes but important for Cp*(OC)2Mn(H3Ga·L) complex. Such distinctive characteristics of the σ-H3Ga·L ligand provides a sharp contrast to that of H3B·L and silane ligands. 相似文献
14.
15.
The semiempirical MO method SINDO1, originally suitable for first- and second-row atoms, is extended to transition metals from scandium to zinc. The core Hamiltonian elements in a symmetrically orthogonalized atomic orbital (OAO) basis set are modified and the parameters are optimized to reproduce the experimental geometries, heats of formation, and ionization potentials. An application of the method to a selected number of molecules, as well as a comparison between calculated and experimental data is reported. 相似文献
16.
Summary Solid tetraphenylboronates of some cations,e.g. [Fe(1,10 phen)3]3+ , [Co(NH3)6]3+, with E° values -0.26V are unstable, either thermally or photo chemically, or both. Products of such redox reactions are identified. The contrasting situation with more reducing cations,e.g. [Cr(en)3 ]3+, is described.On leave from Paisley College of Technology, Renfrewshire, Scotland, U.K. 相似文献
17.
Dr. G. de Brouckére 《Theoretical chemistry accounts》1970,19(4):310-325
A set of molecular orbital calculations based on a particular semi-empirical method, has been undertaken on a homologue series of bis(-2-methylallyl)transition metal (Ni, Co, Fe, Cr) complexes (abbreviated as ML2). Arguments are found for predicting the stability of the NiL2 system, which is the only one that could be synthetized.
Zusammenfassung Eine Reihe von semiempirischen MO-Rechnungen wurde für die homologe Reihe von bis(-2-methylallyl) Metallkomplexen (Ni, Co, Fe, Cr) durchgeführt. Gründe für die Stabilität der Ni-Verbindung, die als einzige synthetisiert wurde, werden angeführt.
Résumé Un ensemble de calculs par une méthode semi-empirique particulière d'orbitales moléculaires a été effectué sur une série homologue de complexes bis (-2-méthylallyl)-métal de transition (Ni, Co, Fe, Cr): ML2.Certains arguments sont trouvés en faveur de la stabilité du système NiL2, le seul à avoir été synthétisé.相似文献
18.
The NDDO method has been extended to include elements withd-orbitals. A parametrization for the first-row transition metals is given, which has been worked out to describe structural properties of transition metal complexes. Applications of the method to the Jahn-Teller distortions of tetrachloro complexes are presented. The NDDO results are compared with those from CNDO and INDO calculations. It turns out that the NDDO method seems to be the most sensitive among the ZDO procedures. 相似文献
19.
20.
Brian F.G. Johnson Raymond L. Kelly Jack Lewis John R. Thornback 《Journal of organometallic chemistry》1980,190(4):C91-C94
The reduction of H2Os3(CO)10S or HOs3(CO)10(O2CMe) with KBH(OPr-i)3 at low temperatures yields unstable formyl complexes which have been identified by 1H NMR spectroscopy; at higher temperatures conversion into stable hydridoanions is observed. 相似文献