Potassium with transition metal chlorides

Colour - A striking feature of transition-metal compounds is their colour. Whether it is the pale blue or pink hues of copper(ii) sulfate and cobalt(ii) chloride, or the intense purple of potassium permanganate, these colours tend to be associated most commonly with transition-metal compounds. It is rare for compounds of main group metals to be highly coloured. 

Strontium is found chiefly as celestite and strontianite. The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Three allotropic forms of the metal exist, with transition points at 235 and 540oC. 

William Christopher Zeise (1789-1847) was a Danish apothecary and professor in Copenhagen, Denmark. He synthesized the first metal-olefin complex by serendipity (this term is explained in Chapter 4), when he treated platinum(IV) chloride with ethanol and potassium chloride K[PtCl3( -C2H4)], sal kalico-platinicus inflammabilis , cf [73], TT-Complexation of olefins at transition metals nowadays comprises a key feature of homogeneous catalysis in terms of olefin activation, with the Wacker-Hoechst process being a prominent example (cf. Section 2.4.1). 

Interaction between a cyano group and a carbon atom of a cyclic enaminone is facilitated by transition metals. Thus, in the absence of coppcr(I) chloride, potassium carbonate does not convert the cyano-enamine (65.6) into a reduced acridinone. Reduced acridines may also be synthesized by cyclization of N-aryl-benzamides with phosphorus oxychloride. 

All the halates decompose on heating, usually above their melting point. In the presence of a transition metal catalyst such as Mn02, the decomposition of KCIO3 to chloride and oxygen starts at 70 °C and is the source of pure oxygen in laboratory preparation. In a series of the halates with the same cation, the thermal stability decreases in the sequence of [lOs]" > [0103] > [Br03] . Potassium chlorate is used in the mixture of safety matches, in pyrotechnic formulations, and as intermediates in the production of perchlorates. 

The presence of a heterosubstituent facilitates deprotonation. For example, the metalation of cyclic vinyl ethers with n-butyl-lithium/potassium tert-butoxide bas been successfully employed in the synthesis of C-glycosides. This reaction proceeds via metalation of the glucal, followed by reaction with tributyltin chloride, to afford the corresponding tin derivative that can be submitted to transition metal-catalyzed cross-coupling reactions (eq 9). 

Complexation studies to date include preliminary examination of interaction with cupric chloride CuCl2. It is clear from clean-up results, however, that even the alkalai metal cation potassium is strongly bound by some of the copol3nners e.g., 5A-5C. Solublization of cupric chloride in carbon tetrachloride was followed visually by strong green-to-blue coloration with polymers lA, 2B, 5A-5C. Evaporation of the solvent gave colored solid complexes with the copper evenly dispersed throughout. Attempts at NMR studies of the complexes were unsuccessful. Current work involves further characterization of the solution behavior and solid complexes with copper salts and with other transition metal complexes. 

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