A left-handed 21 helix with triple chiral components: Synthesis, luminescence and SHG response

A new 21 left-handed helical chain with triple chiral components with the formula, {{Ag2[(1R,1′R,2R,2′R,N1S,N1′S,N2S,N2′S)-4-bppd]}⋅ 2NO3⋅ CH3OH}n (1) [(1R,1′R,2R,2′R)-4-bppd = (1R,1′R,2R,2′R)-N1,N1′-(1,3-phenylenebis(methylene))bis(N2-(pyridin-4-ylmethyl)cyclohexane-1,2-diamine)], has been synthesized by using a prolonged flexible multidentate organic bridging ligand with two (1R,2R)-1,2-diaminocyclohexane subunits. The circular dichroism (CD) spectra and second-harmonic generation (SHG) efficiency measurements of 1 confirmed that it is of structural chirality in the bulk sample. The luminescence properties of 1 indicated that it may have potential applications as an optical material.