Depolymerization of poly（ethylene terephthalate） （PET） was performed in the tubular bomb microreactor which contained the solution of PET in methanol and dibutyltin oxide at the temperature ranging from 433 K to 4...Depolymerization of poly（ethylene terephthalate） （PET） was performed in the tubular bomb microreactor which contained the solution of PET in methanol and dibutyltin oxide at the temperature ranging from 433 K to 473 K, the reaction time from 5 to 45 min and the catalyst-to-PET ratio of 0.3%-2% by weight. The optimal condition for PET depolymerization catalyzed by dibutyltin oxide is the temperature of 443-453 K, the reaction time of 20-25 min and 0.8% by weight of catalyst. By using differential methods, the activation energy for the depolymerization process was found to be 154.05 kJ/mol in the temperature range from 433-463 K.展开更多
Di-O-acetyl sucrose was regioselective synthesized by using dibutyltin oxide in about 60% yield. The structure of acetyl derivative was elucidated by 1H NMR, 13C NMR, 2D-NMR and MS spectral data.
A facile and credible strategy was demonstrated to synthesize two new Sn-O clusters 1 and 2 by the reactions of nBu2SnO with esters directly under mild conditions.Cluster 1 crystallizes in the triclinic system,space g...A facile and credible strategy was demonstrated to synthesize two new Sn-O clusters 1 and 2 by the reactions of nBu2SnO with esters directly under mild conditions.Cluster 1 crystallizes in the triclinic system,space group P1 with a = 13.054（3）,b = 13.137（3）,c = 15.077（3） ,α = 80.009（9）,β = 77.187（10）,γ = 76.075（11）°,Z = 2,V = 2427.3（9） 3,Dc = 1.565 g/cm3,μ（MoKα） = 2.076 mm-1,F（000） = 1152,the final R = 0.0335 and wR = 0.0664 for 9416 observed reflections（I 2σ（I））.Cluster 2 belongs to the monoclinic system,space group P21/c with a = 13.673（3）,b = 13.342（3）,c = 16.296（4） ,β = 104.385（5）o,Z = 4,V = 2879.7（10） 3,Dc = 1.347 g/cm3,μ（MoKα） = 1.751 mm-1,F（000） = 1176,the final R = 0.0306 and wR = 0.0706 for 6390 observed reflections（I 2σ（I））.The crystal structures of the clusters consist of cen-trosymmetric [RCOOSnnBu2OSnnBu2OH）]2 molecules with an almost planar Sn4O4 framework.Each pair of exo-and endo-cyclic tin atoms was linked by one bridge-OH only.In addition,a novel structure of nBu2SnO different from the previous reports was proposed on the basis of 1H-NMR,TG analysis and X-ray diffraction.展开更多
文摘Depolymerization of poly（ethylene terephthalate） （PET） was performed in the tubular bomb microreactor which contained the solution of PET in methanol and dibutyltin oxide at the temperature ranging from 433 K to 473 K, the reaction time from 5 to 45 min and the catalyst-to-PET ratio of 0.3%-2% by weight. The optimal condition for PET depolymerization catalyzed by dibutyltin oxide is the temperature of 443-453 K, the reaction time of 20-25 min and 0.8% by weight of catalyst. By using differential methods, the activation energy for the depolymerization process was found to be 154.05 kJ/mol in the temperature range from 433-463 K.
文摘Di-O-acetyl sucrose was regioselective synthesized by using dibutyltin oxide in about 60% yield. The structure of acetyl derivative was elucidated by 1H NMR, 13C NMR, 2D-NMR and MS spectral data.
基金supported by the National Natural Science Foundation of China (20421202,20372033)
文摘A facile and credible strategy was demonstrated to synthesize two new Sn-O clusters 1 and 2 by the reactions of nBu2SnO with esters directly under mild conditions.Cluster 1 crystallizes in the triclinic system,space group P1 with a = 13.054（3）,b = 13.137（3）,c = 15.077（3） ,α = 80.009（9）,β = 77.187（10）,γ = 76.075（11）°,Z = 2,V = 2427.3（9） 3,Dc = 1.565 g/cm3,μ（MoKα） = 2.076 mm-1,F（000） = 1152,the final R = 0.0335 and wR = 0.0664 for 9416 observed reflections（I 2σ（I））.Cluster 2 belongs to the monoclinic system,space group P21/c with a = 13.673（3）,b = 13.342（3）,c = 16.296（4） ,β = 104.385（5）o,Z = 4,V = 2879.7（10） 3,Dc = 1.347 g/cm3,μ（MoKα） = 1.751 mm-1,F（000） = 1176,the final R = 0.0306 and wR = 0.0706 for 6390 observed reflections（I 2σ（I））.The crystal structures of the clusters consist of cen-trosymmetric [RCOOSnnBu2OSnnBu2OH）]2 molecules with an almost planar Sn4O4 framework.Each pair of exo-and endo-cyclic tin atoms was linked by one bridge-OH only.In addition,a novel structure of nBu2SnO different from the previous reports was proposed on the basis of 1H-NMR,TG analysis and X-ray diffraction.
