Four chiral coordination polymers (CPs), M[(S,S)‐C14H14N2O6] and M[(R,R)‐C14H14N2O6] (M=Zn or Cd), have been exclusively synthesized in high yields with the aid of newly designed chiral ligand under hydrothermal condition. The CPs crystallizing in the orthorhombic nonpolar space group, C2221, reveal three‐dimensional framework structures composed of MO4 tetrahedra and the corresponding homochiral linkers. Powder second‐harmonic generation (SHG) measurements indicate that the nonpolar CPs reveal very strong SHG efficiency of ca. 5–9 times that of KH2PO4 and exhibit type‐I phase‐matching behavior. Density functional theory calculations suggest that the unusually large SHG efficiency found from the nonpolar CPs should be attributable to the synergistic effect of polarizable metal cations and enhanced hyperpolarizability in the donor‐acceptor system originating from the hydrogen bonding in the coordinated linkers.

Systematically synthesized new noncentrosymmetric nonpolar chiral coordination polymers exhibit unusually strong second‐harmonic generation efficiencies attributable to the synergistic effect of polarizable metal cations and increased hyperpolarizability in the donor–acceptor system originating from the robust hydrogen bonding in the coordinated linkers. Details can be found in the Communication by Joonhyuk Kee and Kang Min Ok on page 20656.

Four chiral coordination polymers (CPs), M[(S,S)‐C14H14N2O6] and M[(R,R)‐C14H14N2O6] (M=Zn or Cd), have been exclusively synthesized in high yields with the aid of newly designed chiral ligand under hydrothermal condition. The CPs crystallizing in the orthorhombic nonpolar space group, C2221, reveal three‐dimensional framework structures composed of MO4 tetrahedra and the corresponding homochiral linkers. Powder second‐harmonic generation (SHG) measurements indicate that the nonpolar CPs reveal very strong SHG efficiency of ca. 5–9 times that of KH2PO4 and exhibit type‐I phase‐matching behavior. Density functional theory calculations suggest that the unusually large SHG efficiency found from the nonpolar CPs should be attributable to the synergistic effect of polarizable metal cations and enhanced hyperpolarizability in the donor‐acceptor system originating from the hydrogen bonding in the coordinated linkers.

Chirality is an important concept in chemistry revealing intriguing optical properties such as circular dichroism (CD), circularly polarized luminescence (CPL), etc. As one of the non-centrosymmetric (NCS) classes, chiral materials with extended structures may exhibit unique nonlinear optical (NLO) properties, such as second-harmonic generation (SHG). In this Concept article, a series of recently discovered NCS coordination polymers (CPs) from use of carefully designed chiral organic ligands are reviewed. Combining several metal cations such as lanthanides, lead, zinc, and cadmium with rigid chiral ligands has resulted in interesting CPs with both polar and nonpolar structures. Detailed structures, SHG properties, and structure-property relationships are provided. The importance of hyperpolarizability formed by intermolecular hydrogen boding interactions to SHG is emphasized.

A series of systematically discovered non‐centrosymmetric coordination polymers derived by carefully designed chiral ligands reveal strong second‐harmonic generation efficiencies attributable to the synergistically increased hyperpolarizability achieved by well‐ordered hydrogen bonds. For more information, see the Concept by Kang Min Ok et al. (DOI: 10.1002/chem.202200007).