[(Flu)-(CH₂)₂-(NHC)-CH₂-(NHC)-(CH₂ )₂-(Flu)]^2-: an 'all-organic' hybrid and flexible ligand that enwraps a Ca²⁺ pseudo-tetrahedrally

A conformationally flexible ligand, [(Flu)-(CH2)(2)-(NHC)-CH2-(NHC)-(CH2)(2)-(Flu)](2-) (L), that offers four sequential organic donor modules and enwraps a Ca2+ pseudo-tetrahedrally in a twisted 'S'-shape is devised. The [(L)Ca] synthesis is intriguingly stepwise involving the intermediate [(LH)Ca(HMDS)], whereas [(LH)Li-2(HMDS)] shows the potential for bimetallic chemistry. The bonding is illustrated by energy decomposition analyses.