Fig. 1. Simultaneous generation of complexes [Cu(1,4)2]+ and [Fe(2,3)2]2+ through the self-sorting of their initial reactants. For clarity, the components 1 and 3 and the Cu(i) ions not incorporated into a complex have been omitted from the representation. Top – Reaction conditions: 1 : 2 : 3 : 4 : Cu(BF4) : Fe(BF4)2 (2 : 2 : 2 : 2 : 1 : 1), 3.6 mM, CD3CN, 60 °C, up to 20 days. Partial 1H NMR spectrum (400 MHz, CD3CN, 297 K) of the crude reaction mixture after 18 h and 20 days at 60 °C. Bottom – Reaction conditions: 1 : 2 : 3 : 4 : Cu(BF4) : Fe(BF4)2 (2 : 2 : 2 : 2 : 1 : 1), 20 mM, CD3CN, 60 °C, up to 20 days. The partial 1H NMR spectrum (400 MHz, CD3CN, 297 K) of the crude reaction mixture after 18 h and 20 days at 60 °C. Diagnostic signals of the complexes are colour coded, [Cu(1,4)2]+ in red and [Fe(2,3)2]2+ in purple and [Fe(2,3)(2,4)]2+ in orange. One of the diagnostic signals of the free aldehydes 3 and 4 is highlighted by a green pentagon, and two of the diagnostic signals of the free amine 1 are highlighted by grey squares.
