Thiocyanate, nickel macrocyclic complex

Analogous investigations were performed by Madeja et al. [Ma 76] with the mixed complex consisting of the hydrogen-bond containing nickel(II) macrocyclic complex (I) and thiocyanate ion. The equilibrium constants determined in solutions prepared with various donor solvents are listed in Table 4.8. By comparison with Table 4.7, it can be seen that, with the exception of acetonitrile, the stability of the thiocyanate complex is higher than that of the iodide complex in every solvent this... 

Abbaspour, A., M.A. Kamyabi, A.R. Esmaeiling, and K. Kia (2002). Thiocyanate-selective electrodes based on unsymmetrical benzoN4 nickel(II) macrocyclic complexes. Talanta 57, 859-867. 

The reaction sequence outlined in Scheme 12 illustrates how macrocyclic polyether-thiono diesters such as RR)-lfi6 can be prepared (184) from 0,0-dimethyl 2,6-pyridinedicaibothiolate and (RR)-S4, Potassium thiocyanate forms a 1 1 crystalline complex with (RR)-1S6 and presumably the potassium ion serves as a template for the (1 -I-1) cyclization. Raney nickel desulfurization of (/ R)-186 yields the chiral pyridino-18-crown-6 derivative RR)-191. 

Table 4.8. Stability constants of the mixed complex of the nickel(II) macrocyclic system (I) with thiocyanate in non aqueous solvents [Ma 76]...

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