Heterochiral or Homochiral Self‐Assembly: Mercury(II), Cadmium(II), and Spontaneous Resolution of Silver(I) Complexes Derived from a Racemic Bis(pyridyl) Ligand

A novel racemic bis(pyridyl) ligand (rac‐L) was designed and synthesized by Schiff condensation reaction. Five complexes, [Hg2(LR)(LS)Cl4]·2CH3CH2OH (1), [Cd(LR)(LS)Cl2]n (2), {[Cd(LR)(LS)SO4(H2O)]·11H2O}n (3), {[Ag(LR)2]NO3·CH3CN}n (4a) and {[Ag(LS)2]NO3·CH3CN}n (4b) have been synthesized and characterized. The different geometric features of complexes 1–4 were determined by single‐crystal X‐ray diffraction. The crystal structures show that the self‐assembly with racemic ligands can lead to homochiral or heterochiral complexes, through self‐recognition or self‐discrimination of the ligand units. Complex 1 exists as a 26‐membered binuclear heterochiral macrocycle. Complexes 2 and 3 form 1D mesomeric looped chain coordination polymers with different heterochiral self‐assembly types. More interestingly, two novel 2D homochiral coordination polymers 4a and 4b were obtained as racemic conglomerates via spontaneous resolution. Furthermore, the thermal stabilities and luminescence properties of complexes 1–4 were investigated. Self‐assembly with racemic ligands can lead to homochiral or heterochiral complexes, through self‐recognition or self‐discrimination of the ligand units. Complex 1 is a 0D binuclear heterochiral macrocycle, complexes 2 and 3 form 1D mesomeric looped chain coordination polymers, and two 2D homochiral coordination polymers 4a and 4b were obtained as racemic conglomerates via spontaneous resolution.