从麦草碱法制浆黑液中提取木质素,精制后,以苯乙酮为木质素的模型化合物,对催化剂组成及溶剂进行了考察.在此基础上,以NaBH4/I2为催化剂,无水乙醇为溶剂,对木质素进行加氢还原裂解反应研究.考察了温度和时间对木质素催化加氢效果的影响,采用红外光谱(FTIR)、元素分析及凝胶渗透色谱分析(GPC),表征木质素反应前后结构的变化.凝胶渗透色谱分析表明,加氢还原后木质素的分子量明显降低.采用自动电位滴定法测定反应前后木质素中总羟基含量,反应后木质素中总羟基含量为10.19%.得到了NaBH4/I2催化木质素加氢还原反应的最优条件:以1,2-二氯乙烷和乙醇(2∶1,v/v)作溶剂,m(NaBH4)∶m(I2)=1∶1,温度175℃,反应时间15 h.
We studied the reactivity of an osmium vinyl complex containing a coordinated hydroxyl group OsCl2(PPh3)2[CH=C(PPh3)CHPh(OH)] (1) toward bidentate ligand 1,4-bis(diphenylphosphino)butane (DPPB),acid ligand (CO),base (Cs2CO3) and heat.Two osmium vinyl complexes OsCl2(dppb)[CH=C(PPh3)CHPh(OH)](2) and OsCl2(CO)2(PPh3)[CH=C(PPh 3)CHPh(OH)] (3),as well as two relatively rare phosphonium-containing osmafuran complexes Os(2-OCOO)(PPh3)2[CHC(PPh3)CPhO](4) and OsCl2 (PPh3)2[CHC(PPh3)CPhO](5),were obtained in high yields from these reactions.All products were characterized by NMR spectroscopy,elemental analysis,and their structures were further confirmed by single crystal X-ray diffraction.
LIU BinZHAO QianYiWANG HuiJuanZENG BiRongCAO XiaoYuXIA HaiPing
