Intercalation von Lanthanoidtrichloriden in Graphit

Intercalation of Lanthanide Trichlorides in Graphite The reactions of the whole series of lanthanide trichlorides with graphite have been investigated. Intercalation compounds have been prepared with the chlorides of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y whereas LaCl₃, CeCl₃, PrCl₃ and NdCl₃ do not intercalate. The compounds were characterized by chemical and X-ray analysis. The amount of c-axis increase in consistent with the assumption that the chlorides are intercalated in form of a chloride layer sandwich resembling the sheets in YCl₃. The chlorides which do not intercalate crystallize in the UCl₃ structure having 3 D arrangements of ions. Obviously, these chlorides cannot form sheets between the carbon layers. The ability of AlCl₃ to volatilize lanthanide chlorides through complex formation in the gas phase can be used to increase the intercalation rate strikingly.     

Zur Bestimmung von Graphit in Mineralien

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Die spektrochemische Bestimmung von Bor in Graphit

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Eine einfache Bestimmung von Uran in Graphit

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Intercalation von Metallnitraten in Graphit. IV. Die Reaktion von wasserfreiem Kupfer(II)-nitrat mit Graphit

Intercalation of Metal Nitrates in Graphite. IV. Reaction of Anhydrous Copper (II) Nitrate with Graphite By heating of Cu(NO₃)₂ and Cu(NO₃)₂ · N₂O₄ with graphite (160–200°C, 1–8 d) samples of stage 4, 5, and 6 of Cu(NO₃)₂ graphite were obtained, which were characterized by X-ray powder diffraction and chemical analysis. 4^th stage: I_c = 2030 pm, C:Cu ≈ 40:1. 5^th stage: I_c = 2365 pm, C:Cu ≈ 50:1. 6^th stage: I_c = 2700 pm, C:Cu ≈ 60:1. The intercalate thickness was found to be 690 pm. Heating with Cl₂ yields the corresponding stages of CuCl₂ graphite.     

Die Gasphasenintercalation von Graphit durch SbCl4F

Gas Phase Intercalation of Graphite by SbCl₄F Gas Phase Intercalation of Graphite by SbCl₄F using a two-zone technique is a method to prepare intercalation compounds of different stage index n in temperature range between 120 and 140°C. The reaction is a process of successive decrease of stage index. Increasing the reaction time, i. e. concentration, regions of pure stages alternate with two-phase regions. Intercalation compounds were characterized by X-ray technique, EPMA, and chemical methods. The compounds are stable in ordinary air, with aqueous HCl as well as KOH only pentavalent but not any trivalent antimony can be removed. The identity periods along c-axis in pure stages are I_c = 9.33 Å (n = 1), 12.72 Å (n = 2), 16.06 Å (n = 3) and 19.40 Å (n = 4). A (√7 × √ 7) 19.1° in-plane structure of intercalants was found. The uptake curve of mass with time reveals a discontinuity connected with formation of stage 2. Concave shape of curve during starting period at 120 and 125°C will be interpreted as a consequence of an induction time. From X-ray and EPMA studies it may be concluded that nucleation at the prismatic crystal edges controls the kinetics of reaction. Assuming a first order kinetics of filling the vacant sites, the same activation energy in case of formation of stage 1 and stage 2 have been determined approximately (97 and 102 kJ/mol).     

Die spektrographische Bestimmung von Verunreinigungen in radioaktivem Graphit

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Zur spektrographischen Bestimmung von Spuren Bor in Graphit

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Untersuchung von Schokolade

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Untersuchung von Honig

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Untersuchung von Vitaminen

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Untersuchung von Honig

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