DFT study of lactide ring-opening polymerizations by aluminium trialkoxides: Understanding the effects of monomer, alkoxide substituent, solvent and metal

Mechanism of ring‐opening polymerization of l‐lactide by lanthanide aryloxide: A theoretical study on the effect of the aryloxide ligands on the process

“…Note that this La∙∙∙OAr species 3b I has not been reported in previous experiments on similar ROP process with rare earth aryloxide catalyst [6, 15–17, 19, 21, 25, 26, 46, 47]. This structural arrangement of the sterically bulky ligand prior to ring opening has also been found in other relevant studies on lactide ROP [48–50]. In addition, we did not observe any pendulum transition state after TS1b I , as previously reported in the literature [9, 51, 52] (see Figure S7 for relaxed potential energy scan of the La − O1 − C* − O2 angle between 3b’ I and 4b’ I ).…”

“…6b' I) by La(OTMP) 3 was also included (shown in blue). [48][49][50]. In addition, we did not observe any pendulum transition state after TS1b I, as previously reported in the literature 51, 52] (see Figure S7 for relaxed potential energy scan of the La À O1 À C* À O2 angle between 3b' I and 4b' I).…”

Investigation of initiator metal efficiency in the ring‐opening polymerization of lactones: an experimental and computational study

“…First, all the complexes used here are effective initiators in polymerization despite the differences in their efficiencies. Inspired by previous studies, [59][60][61] we think that polymerization proceeds through the anionic coordination-insertion mechanism. In this mechanism, after the ring-opening step, the anionic end and the new monomer form a coordination bond with the metal, allowing the polymerization reaction to proceed.…”

N-(2-(Diphenylphosphino)ethyl)-2-alkyl-5,6,7,8-tetrahydro-quinolin-8-amines iron(ii) complexes: structural diversity and the ring opening polymerization of ε-caprolactone

“…This may be due to the higher activation free energy required to initiate the reaction in polar solvents, according to DFT calculation. 68 According to the optimized conditions by Fe6 , the ring opening polymerization of ε-caprolactone by other iron( ii ) complexes Fe1–Fe5 was also conducted at the molar ratio of [ε-CL] : [Fe] = 1500 : 1 and at 90 °C within 10 min (runs 18, 25–29, Table 4). All these iron( ii ) complexes with different substituents showed high catalytic activity except for Fe4 with low conversion, and the monomer conversions were in the order Fe1 ( H , 93%) > Fe2 ( Me , 89%) > Fe3 ( i Pr, 88%) > Fe4 (Cl, 55%); Fe5 (MeC 6 H 2 , 98%) > Fe6 ( i PrC 6 H 2 , 87%).…”