Coordinatively unsaturated double-stranded helicates [(H2 L)2 Eu2 (NO3 )2 (H2 O)4 ](NO3 )4 , [(H2 L)2 Tb2 (H2 O)6 ](NO3 )6 , and [(H2 L)2 Tb2 (H2 O)6 ]Cl6 (H2 L=butanedioicacid-1,4-bis[2-(2-pyridinylmethylene)hydrazide]) are easily obtained by self-assembly from the ligand and the corresponding lanthanide(III) salts. The complexes are characterized by X-ray crystallography showing the helical arrangement of the ligands. Co-ligands at the metal ions can be easily substituted by appropriate anions. A specific luminescence response of AMP in presence of ADP, ATP, and other anions is observed. Specificity is assigned to the perfect size match of AMP to bridge the two metal centers and to replace quenching co-ligands in the coordination sphere.

Synthesis of binuclear Cu(II) terminally closed [2+2]-double-stranded helicate-like macrocycles 1, 1 0 ,1 00 , 2, 2 0 , 2 00 and 2+4-μ 4-oxo tetranuclear open frame complexes 3, 3 0 , 3 00 , 4, 4 0 , 4 00 are established. Adapting one-pot selfassembly technique from simple three components systems: 1,1 0-binaphthyl-2,2 0-diamine, 4-methyl-2,6-diformyl phenol and cupric salts, the helicate-like [2+2]-macrocyclic complexes 1-1 00 , 2-2 00 and 2+4-μ 4-oxo tetranuclear complexes 3-3 00 , 4-4 00 were obtained by appropriately altering the reaction condition such as temperature and subcomponent ratio. Density Functional Theory (DFT) calculations were carried out for understanding the structural geometries, intermediates involved in the diverse formation of [2+2] and 2+4 frameworks. The single crystal X-ray structures obtained for 1 0 , 2 and 3 confirms the self-assembly process in line with DFT. This detailed analysis tempted us to derive a plausible mechanism for this long standing challenge in the synthesis of such macrocycles using 1,1 0-binaphthyl-2,2 0-diamine (BNDA) and aromatic aldehyde. The chiroptical properties of enantiopure complexes and their catalytic applications in asymmetric oxidative coupling of 2-naphthol to chiral 1,1'-Bi-2-naphthol (BINOL) achieved in good yield and ee were discussed.

The ligand L1 of 4-methyl-2,6-diformylphenol and L2 of 4-tert-butyl-2,6-diformylphenol are synthesized through Schiff base condensation with rac-, (R)-(+), or (S)-(−)-1,1′-binaphthyl-2,2′-diamine (BNDA). As a result, the racemic L1 rac, L2 rac, and enantiopure L1 RR, L1 SS, L2 RR, and L2 SS ligands are obtained incorporating Cu­(II) and Zn­(II) salts by a simple one-pot metal template method. The series of dinuclear complexes of [M2LX2] (here, M = Cu2+, Zn2+; X = acetate ion, chloride ion; L = L1 RR, L1 SS, L1 rac, L2 RR, L2 SS, L2 rac) formulas are obtained in common. Among them, the single crystal X-ray structures for [Zn2L1 rac(OAc)2] and [Zn2L1 SSCl2] complexes are obtained. The detailed crystal structure and the chiroptical studies performed on these complexes dictates a self-sorting behavior in their self-assembly process and illustrate a chirality transfer from the ligand to the metal center on the complexes. The enantiopure dinuclear complexes [M2LRRX2] and [M2LSSX2] generate enantiopure ΛΛ and ΔΔ isomers, respectively, but the racemic complexes produce only homochiral ΛΛ and ΔΔ assemblies. The detailed studies based on UFLC (Ultra Fast Liquid Chromatography), CD, and single crystal X-ray structure together show the absence of heterochiral ΛΔ mesocate. All these complexes are adapted as catalysts for desymmetrization of various mesodiols, and the enantiopure complexes are found to give efficient enantioselectivity in desymmetrization of mesodiols with benzoyl chloride to monobenzoylated ester providing 98% yield and 92% ee.