Synthesis of Poly (thioether) s by Nucleophilic Substitution of Chromium-Arene Complex

以对二氯苯和六羰基铬为原料制备了铬-芳烃络合物。详细考察了该配合物在有机溶剂中的稳定性和亲核取代芳香族的反应活性。最终的纯化工艺由柱层析改为升华。光谱数据和熔点与文献相符，通过在325 nm处吸收光谱的变化考察了该配合物在有机溶剂中的稳定性。在非极性溶剂中吸附1h后，吸光度由最初的70%降至70%。这种减少与水和氧气的存在无关。溶液中可能存在配体的交换反应或解离反应。在100ﾟC下，苯酚和苯硫酚在二甲亚砜中进行了亲核取代芳香族反应，通过高效液相测定从粗品中估算了单取代和双取代产物的比例。通过硫酚的反应得到二取代产物。事实表明，苯硫酚的二次取代反应进展顺利，而醚键阻碍了苯酚的二次取代反应。由于该络合物在有机溶剂中不太稳定，因此通过I_2的氧化有效地进行了解配反应，其聚合反应尚未见报道。以该络合物为单体进行缩聚，需要进行快速繁殖反应。

Chromium-arene complex was prepared from p-dichlorobenzene and chromium hexacarbonyl. Stability in organic solvents and reactivity of the complex for nucleophilic aromatic substitution were investigated in detail.The complex was prepared from chromium-hexacarbonyl and p-dichlorobenzene, as reported in literature. The final purification process was changed to sublimation instead of column chromatography. Spectroscopic data and its melting point were consistent with those in literature.Stability of the complex in organic solvents is investigated by the change of absorption at 325 nm. The absorption decreased to 70% from the initial one after 1 h in non-polar solvents. The decrease is independent on the presence of water and oxygen. Exchange reaction or dissociation of ligand may exist in the solution.Nucleophilic aromatic substitutions by phenol and thiophenol were carried out in DMSO at 100ﾟC.The ratio of mono and disubstituted product was estimated from the crude product without isolation by HPLC measurements. Disubstituted product was obtained by the reaction of thiophenol. The fact indicates that second substitution by thiophenol proceeds smoothly whereas ether bond retard the second substitution by phenol. Decomplexation reaction proceeded efficiently by oxidation by I_2.Polymerization of the complex has not been investigated because the complex is not very stable in organic solvents. Rapid propagation reaction is required to use the complex as a monomer for polycondensation.