Cobalt phosphorus containing

Table 29 Preparation and Structures of Phosphorus-containing Cobalt Complexes...

Theories and principles of the characterization techniques are not described here. For consistenc), all the catatysts described in this review are referred to with the same nomenclature, although a different nomenclature is sometimes used in the cited publications. Each catalyst component (element) separated by the symbol indicates the sequence of its introduction into the catalyst formulation from right to left. Those separated by the symbol 7 between right and left belong to the support material and the elements on the support, respectively. For example, NiMo-P/Al refers to a catalyst prepared such that the phosphorus-containing precursor is loaded on the alumina support first, followed by nickel and molybdenum, which are introduced simultaneously. CoMo/Al — P refers to a catalyst in which cobalt and molybdenum are introduced simultaneously onto an alumina support doped with phosphorus-containing species. Each element may represent its oxide or sulfide forms. In all cases, A1 refers to the alumina-based support or to its hydroxide precursor. 

To identify the phosphorus-containing compounds described in the previous sections and the related species containing aluminum, molybdenum, cobalt, or nickel which might be present in hydrotreating catalysts, it is convenient to use techniques such as NMR, IR, UV. and Raman spectroscopies and XRD. XRD is useful for characterizing crystalline bulk compounds, and other techniques are appropriate for well-dispersed species and amorphous phases. Typical IR, Raman, and NMR data presented in Tables VI, VII, and VIII, respectively, could be the basis for such identifications. 

In the various preparations, ammonium heptamolybdate, cobalt nitrate, or nickel nitrate are preferred. The preferred phosphorus-containing precursors are phosphorus pentoxide, phosphoric acid, or their anion derivatives such as ammonium dihydrogen phosphate (NH4H2PO4) be-... 

To understand the complex interaction of phosphorus-containing species with alumina and with the other elements (molybdenum, cobalt, or nickel) introduced in the catalyst formulations, it is important to examine the chemistry involved in the preparation steps. In this section, adsorption of phosphorus-containing species on alumina is discussed. 

This report also describes two new examples of nitrato-metallate coordination compounds which involve a phosphorus-containing ligand. One is the complex [AgL2N03] and the other the blue diamagnetic cobalt(I) complex anion [CoL(N03)2] Of the more than 100 compounds reported in the literature, which are suspected to contain coordinated nitrate, the 12 examined by x-ray diffraction technics are listed in Table II. Two reviews on metal-nitrate interactions have appeared recently (3, 19), so only some general observations will be made here. 

Magnetochemical measurements for the solid phosphorus-containing zinc, iron, nickel, and cobalt tris-diiminates showed that the first two are diamagnetic and low-spin complexes. The cobalt and nickel(II) complexes proved to be high-spin clathrochelates with magnetic moments of 4.91BM (S=3/2) and 3.11BM (S=l), respectively [92, 93]. 

The UV-vis spectra of phosphorus-containing cobalt(II) and nickel(II) diiminates were obtained both in solution and in the solid state (the [CoPcc(BF)](BF4) and [NiPcc(BF)](BF4) complexes were diluted in the monocrystal of zinc clathrochelate). Pure crystals of... 

From a mining point of view, deposits of economic interest must contain manganese ores with more than 35 wL% Mn to be considered profitable, although some commercially mined deposits, especially in the CIS, India, and China, are well below this level. As well as the ore grade, mineral hardness and the presence of other elements such as copper, cobalt, phosphorus, sulfur, and arsenic is important in determining the viability of the ore body for development. 

Cobalt clusters containing semi-interstitial phosphorus atoms have been prepared using W(CO)4(PH3)2 and Co2(CO)g at room temperature. Reaction with equimolar concentrations affords octanuclear Cog(p6-P)2(p-CO)(CO)ig (3), consisting of four cobalt and two phosphorus atoms in a distorted octahedral arrangement with four faces capped by Co(CO)3 units. The same reaction using a four-fold excess of dicobalt octacarbonyl affords small amounts of [Coio(p7-P)2(p-CO)6(CO)ig] (4) along with the hexa-nuclear product (5). ... 

Miller (90), King (209, 210), and Bruce (211) first observed the formation of neutral metal fluoride species and metal fluoride-containing ions in the mass spectra of pentafluorophenyl derivatives of phosphorus, germanium, silicon, and phosphido-bridged iron carbonyls (90) and aliphatic and aromatic fluorocarbon derivatives of iron, cobalt (209-211),... 

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