Cobalt pentaamine complex

Outer-sphere Cr " reductions of nitrite-bonded pentaamine cobalt(III) complexes are reported. In contrast to other species examined, the cyanoacetate complex shows acid dependence behavior consistent with formation of a bridged intermediate (1) in which outer-sphere electron... 

Metal Salts and Metallic Salt Complexes Various metallic cations can be encountered Co, Fe, Ni, Cu, Cr, and so on [77]. For example, the decomposition of azido-pentaamine cobalt (III) yields an initiating azide radical the reductive interaction between the chromic acid and a suitable monomer such as acrylamide generates a radical on the monomer (10.37) [78]. Other systems are described in Ref. [79]. 

Mn-Mejtacn (Figure 16.11) is still used in automatic dishwashing products, where color and fiber damage is of lesser importance. Another metal complex used in machine dishwashing detergents is pentaamine acetate cobalt (III) nitrate (PAAN) [34]. This highly water-soluble, relatively inexpensive catalyst is effective at very low concentration. 

Replacing the perchlorate anion in pentaamine cobalt (III) perchlorate complexes seems to be a logical way of eliminating the potentially ecologically problematic anion. The effect of such replacement was studied by Ilyushin et al. using dinitroguanidine which was considered suitable due to its ability to form complexes, its enthalpy of formation, and its oxidizing ability [27]. 

For comparison, Ilyushin et al. [27] selected complex cobalt(III) pentaaminate perchlorates having temperature of decomposition in the range 265-280 °C and initiating efficiency around 0.2 g for RDX. 

The temperature of the start of fast decomposition (DTA, 5 °C min ) decreases by 80-100 °C when the perchlorate anion is exchanged for dinitroguanidine or azide. Unlike pentaamine (5-nitro-2//-tetrazolato-iV )cobalt(III) perchlorate (NKT), which decomposes in one step, complex I decomposes in four steps when heated by 5 °C min . It also loses crystal water around 110 °C. 

Nitrogen-bonded chromium(III) products are detected in the reductions of a number of pentaamine cobalt(III) tetrazole complexes by chromium(II). The rate laws show inverse [H dependences and rate constants consistent with an inner-sphere mechanism in all cases. Product isolation confirms remote attack by [Cr(H20)6 on the 4-cyanobenzoic acid derivative [(NH3)5CoNCC6H4C02H] and its deprotonated form (pX 2.51). The [V(H20)6] reaction is also consistent with a remote attack mechanism, while the 3-cyanobenzoic acid complex reacts by an outer-sphere pathway suggesting the possibility of a remote bridged outer-sphere... 

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