Cobalt ammine complex

Explosive Sensitivity of Cobalt Ammine Complexes , NOTS 1884, Navord 6639 (Oct 1957), AD 201554 (19) R.L. Carlin J.O. Edwards,... 

B.Taylor B.Joyner,"Study of Explosive Sensitivity of Cobalt Ammine Complexes,V NavOrd Rept 5639(1957)(UXNot consulted)... 

TABLE 2.2 Chain Theory Structure Predictions for a Series of Cobalt Ammine Complexes Based on the Number of Reactive Cl-... 

In this experiment, we wish to accurately measure the amount of NH3 that is released from a known amount of cobalt ammine complex. To do so, the released NH3 is delivered into a beaker containing a known excess amount of strong acid, HC1. The reaction of NH3 with HC1 quantitatively introduces the second weaker acid, NH4+, into the solution, equation (2.8). 

A potentiometric titration will be run using a solution of your cobalt(III) complex and aqueous silver nitrate (AgN03) as a titrant. AgN03, which is soluble in aqueous solution, undergoes a double displacement reaction with the cobalt ammine complex according to equation (2.10). 

EXPERIMENT 2.7 CONFIRMING YOUR ANALYSIS—VISIBLE SPECTROSCOPY OF COBALT AMMINE COMPLEXES... 

Results Summary for Visible Spectroscopy of Cobalt Ammine Complexes... 

In 1995, Morgan et al. synthesized a layered aluminophosphate compound by using a chiral cobaltammine complex as the template for the first time.[61] Recently, the Jilin group has synthesized a number of 2-D layered and 3-D open-framework metal phosphates by using a racemic mixture or an optically pure chiral metal complex as the template, and has systematically studied the chirality transfer from the guest chiral complex templates to the host inorganic open frameworks.1901 Table 7.15 lists some metal phosphates and oxides with open-framework structures templated by optically pure or racemic cobalt ammine complexes. 

In this experiment you will start with an aqueous solution of cobalt(II) chloride, C0CI2. Ammonium chloride, NH4CI, will be added to provide a source of additional Cl", and aqueous ammonia, NH3, will be added to provide potential NH3 ligands. Finallly, hydrogen peroxide, H2O2, will be added to oxidize Co(II) to Co(III). After the reaction is complete, you will filter crystals of your cobalt-ammine complex. It is not uncommon in chemical syntheses that several products can be formed from the seuae set of reactants. In this experiment you should consider [Co(NH3)6]Cl3, [Co(NH3)5Cl]Cl2, and [Co(NH3)4Cl2]Cl as possible products (See PRELABORATORY QUESTION 1). Formation of one of the products can often be favored by subtle changes in the mole ratios of the reactants, the particular catalyst used, or conditions such as temperature. After purification of the primary product, its identity can be determined by analyses or by instrumental techniques. In this experiment, you will use two independent analyses for this purpose. 

Metal-complex adsorption can directly lead to surface reaction, as has been observed recently for cobalt ammine complexes adsorbing over carbon substrates [41, 42]. The uptake of cobalt hexaammine (CoHA), [(NH3)6Co]+3... 

In 1912 Shibata moved to Paris to study under Georges Urbain (1872-1938). He intended to study the rare earth elements, but Urbain advised him not to do so because such study required tedious fractional crystallization, which was not suitable for a foreign chemist with only limited time to spend. Instead, Urbain suggested that Shibata carry out absorption spectrographic studies of cobalt complexes. Fortunately, Shibata was able to use the newly obtained medium-sized quartz spectrograph of Adam Hilger, type E2, and he carried out absorption measurements of cobalt-ammine complexes (5). In Urbains s laboratory Shibata also learned from Jacques Bardet the technique of emission spectrographic analysis, which Shibata later used to analyze the rare earth minerals found in Japan. 

A few coordination compounds had been known for many years as a result of accidental discoveries. The first recorded observation of the deep blue colour of the tetraamminecopper(ll) ion was made in the sixteenth century by Andreas Libavius when he left some brass standing in a solution of lime water saturated with sal ammoniac (ammonium chloride). Prussian blue was obtained accidentally in 1704 by Diesbach, a manufacturer of artists pigments. It was the cobalt-ammine complexes which were to play such an important role in chemical theory, and the first of these to be isolated in the solid state was the compound now known as hexaamminecobalt(lll) oxalate, [Co(NH3)5]2(C204)3. This was described in 1822 by Leopold Gmelin (1788-1853). 

Table 12.1 The proposed formulae of four cobalt-ammine complexes...

It is also possible to have more complicated inorganic ions to balance the charge of a sulfatometallate. The neodymium compounds with hydrazinium and hydroxylammonium counterions have been synthesized and characterized by thermoanalytical methods (Bukovec, 1985 Bukovec and Bukovec, 1985). Sakamoto (1984) has reported the preparation and properties of a series of La compounds with cobalt ammine complex cations, e.g., [Co(NH3)g][La(S04)3] H2O. 

Three classes of amine photogenerator were examined for this application cobalt-ammine complexes (74), benzyl carbamates (9, 75), and o-nitrobenzyl carbamates (9, 16). The most efiective class of amine photogenerator for this application has been the o-nitrobenzyl carbamates 1-2. 

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