Chiral diphosphine ligands with different dihedral angles (C(n)TunaPhos, n = 1-6) were synthesized and adopted as chiral selectors to recognize amino acids and mandelic acid. The influences of dihedral angles, organic solvents, pH of aqueous phase and chiral extractant concentration on enantioselectivities (alpha) were investigated. The results revealed that C(n)TunaPhos is more efficiency than MeO-BIPHEP for its rigidity in stereochemistry. The enantioselectivities of chiral diphosphine ligands can be improved by regulating dihedral angles. The most efficient C(n)TunaPhos for Phenylalanine (Phe), homophenylalanine (Hphe), 4-nitro-phenylalanine (Nphe) , 3-chloro-phenylglycine (Cpheg), mandelic acid (MA) and 2-Cl-mandelic acid (CMA) were C(6)TunaPhos-Cu, C(6)TunaPhos-Cu, C(4)TunaPhos-Pd, C(5)TunaPhos-Cu, C(4)TunaPhos-Cu and C(2)TunaPhos-Cu, respectively. In addition, the possible recognition mechanisms of C(n)TunaPhos-metal complexes toward amino acid and mandelic acid were discussed. The results of our work may provide important reference for the design of efficient chiral extractants.