Programmed Helicity in Self‐Assembled Hydrogen‐Bonded Chains of Chiral Copper( II ) Complexes

The copper( II ) complexes [Cu(H 2 L 1 )Cl 2 ] 2 [CuCl 4 ] · CH 3 CN · H 2 O (HL 1 = N ‐6‐(4‐hydroxyphenyl)‐2‐pyridylmethyl‐ N , N′ , N′ ‐trimethylethylenediamine), [Cu(HL 2 )Cl 2 ] (HL 2 = N ‐4‐hydroxybenzylmethyl‐ N , N′ , N′ ‐trimethylethylenediamine)and [Cu 2 (μ‐L 3 ) 2 (H 2 O)(ClO 4 )]ClO 4 · H 2 O (HL 3 = N ‐2‐hydroxybenzylmethyl‐ N , N′ , N′ ‐trimethylethylenediamine) were prepared and characterised in acetonitrile solution (by ESI‐MS, EPR and UV/Vis‐NIR spectroscopy) and in the solid state (by X‐ray crystallography). Each copper( II ) complex is chiral and has a potential inter‐complex hydrogen‐bond donor group. Upon crystallisation, all three copper( II ) complexes undergo spontaneous enantioselective self‐assembly into hydrogen‐bond‐linked helices.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)