SalenAl(OPr)催化CO_2和氧化环己烯共聚反应

SALENAl(OPr) CATALYST FOR THE COPOLYMERIZATION OF CO_2 AND CYCLOHEXENE OXIDE

SalenMX has drawn much attention recently,because it is nonsensitive to moisture and effective for copolymerization of CO2 and epoxides.However,usually expensive organic metal compounds were used.A low cost procedure of SalenMX preparation is described that SalenAl（OPr） can be obtained by using aluminium iso-propoxide reacted with SalenH2 in tetrahydrofuran at room temperature overnight.The catalyst precursor Schiff-base SalenH2 （N,N′-Bis（salicylidene）-1,2-phenylenediamine） was synthesized by refluxing 2 equiv salicylaldehyde and 1 equiv of 1,2-phenylendiamine in methnol for a period of time.SalenH2 and SalenAl（OPr） were characterized by FT-IR,mass Spectroscopy,UV-Vis and 1H-NMR.The copolymerization of carbon dioxide and cyclohexene oxide（CHO） was carried out at 80℃ for a certain period time using 50 mg SalenAl（OPr） as catalyst.SalenAl（OPr） had been shown to be an effective catalyst for the copolymerization of CO2 and CHO along with a small quantity of byproduct cyclic carbonate.The addition of various cocatalysts,including DMAP,N-MeIm,DBU and Bu4NCl or Bu4NBr salts can greatly enhance the rate of copolymerization.The copolymers were produced with >95% carbonate linkages and <5% cyclic carbonates.The highest catalytic efficiency is 190 g copolymer per g catalyst.

SalenMX has drawn much attention recently, because it is nonsensitive to moisture and effective for copolymerization of CO2 and epoxides. However,usually expensive organic metal compounds were used. A low cost procedure of SalenMX preparation is described that SalenAl （OPt） can be obtained by using aluminium iso- propoxide reacted with SalenH2 in tetrahydrofuran at room temperature overnight. The catalyst precursor Schiff-base SalenH2 （N, N＇-Bis（salicylidene）-1,2-phenylenediamine） was synthesized by refluxing 2 equiv salicylaldehyde and 1 equiv of 1,2-phenylendiamine in methnol for a period of time. SalenH2 and SalenAl（OPr） were characterized by FT-IR,mass Spectroscopy, UV-Vis and 1H-NMR. The copolymerization of carbon dioxide and cyclohexene oxide （CHO） was carried out at 80℃ for a certain period time using 50mg SalenAl（OPr） as catalyst. SalenAl（OPr） had been shown to be an effective catalyst for the copolymerization of CO2 and CHO along with a small quantity of byproduct cyclic carbonate. The addition of various cocatalysts, including DMAP, N-MeIm, DBU and Bu4NCl or Bu4 NBr salts can greatly enhance the rate of copolymerization. The copolymers were produced with 〉 95 % carbonate linkages and 〈 5 % cyclic carbonates. The highest catalytic efficiency is 190 g copolymer per g catalyst.