Favorable Propylene-Incorporated Terpolymerization of Ethylene with CO Mediated by Cationic [P,O]-Pd and Ni Complexes

Abstract

Commercial polyketone materials are generally produced by palladium-catalyzed terpolymerization of ethylene and α-olefin with carbon monoxide (CO), and rare examples were reported regarding the incorporation of propylene into an ethylene/CO copolymer chain using a cost-effective nickel catalyst. In this study, we have developed a series of [P,O]-type cationic Pd and Ni complexes supported by a diphosphazane monoxide (PNPO) platform, and the electronic and steric effect on phosphine, amine, and phosphine oxide moieties is systematically investigated for terpolymerization in terms of activity, propylene/CO (C3) incorporation, and molecular weight control. It is observed that the melting temperature (T m) is proportional to the number of C3 incorporations present in the polymer chain, and the incorporated propylene does not affect the degradation temperature substantially, thus broadening the processing temperature window of the resultant polyketones. Notably, in comparison with dppp-type catalysts, PNPO catalysts exhibited a higher preference for propylene consumption, which is of great importance for making more efficient use of α-olefin resources.

Epitaxial Growth of MgGa2O4/CsPbBr3 Heterostructure with Controlled Defect Tolerance for Dynamic Photoluminescence

“…[7,8] Since dynamic PL properties are associated with trap filling in the electronic transition levels, rich and tunable defects are urgent for dynamic PL implementation. [7][8][9][10][11] Currently, only a few dynamic PL materials have been reported in several inorganic persistent phosphors. Therefore, it remains a challenge to explore novel strategies and new systems to construct diverse and color controllable dynamic PL in versatile systems.…”

“…Thus, the construction of non-charge transfer type epitaxial layers are an ideal choice for ensuring stable luminescence of perovskite and holding promise to achieve dynamic PL. [33] Notably, the spinel MgGa 2 O 4 crystal exhibits blue luminescence originating from the self-activation of octahedral GaO 6 , [11] in which the strong binding energy between photogenerated electron (Ga 3+ ) and hole (O 2− ), defined as Frenkel excitons, is expected to prevent the interface charge-transfer, making it a promising epitaxial layer to realize anti-fluorescence quenching. To date, there is still no report of dynamic PL modulated by engineering defect tolerance in halide perovskite heterostructure.…”