The syntheses, structures, and catalytic properties for lactones polymerization of eight novel yttrium complexes containing an amine-bis(benzotriazole phenolate) ((BiBTP)-Bi-C1NN) ligand are reported. A series of nitrophenolate (NP)-type of ligands possessing R substituents with variable electronic properties (R = NO2, Cl, H, CH3) on ortho and/or para position attached to the phenolate rings have been selected and further reacted with (BiBTP)-Bi-C1NN-H-2 proligand and YCl3 center dot 6H(2)O. Two series of complexes, [Y((BiBTP)-Bi-C1NN)(TNP)(MeOH)(2)] (3), [Y((BiBTP)-Bi-C1NN)(2,4-DNP)(MeOH)(2)] (4) and [Y((BiBTP)-Bi-C1NN)(2,5-DNP)(MeOH)(2)] (5) with two MeOH molecules as initiators as well as [Y((BiBTP)-Bi-C1NN-H)(CNP)(2)] (6), [Y((BiBTP)-Bi-C1NN-H)(2-NP)(2)] (7) and [Y((BiBTP)-Bi-C1NN-H)(MNP)(2)] (8) with two NP derivatives, were synthesized. Their ring-opening polymerizations of L-lactide (L-LA) were investigated for all complexes in order to further understand the correlations between the inductive effect of substitutions and catalytic properties. Particularly, the activity and controllability of yttrium complexes 3 and 5 were improved dramatically comparing with the literature complex with the similar coordination environment, [Y((BiBTP)-Bi-C1NN)(NO3)(MeOH)(2)], which can be a successful example to enhance the catalytic properties by exchanging coordinate molecules. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019