Electrochemical synthesis of polygermanes
Electrochemical synthesis of polygermanes
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多锗烷的电化学合成
DOI：
10.1016/s0013-4686(98)00173-x
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
H. Hamano
中科院分区：
文献类型：
--
作者：
Mitsutoshi Okano;K. Takeda;Takeshi Toriumi;H. Hamano
电化学合成了五种二烷基取代和三种苯基取代的聚锗烷。其中，α-、二戊基和二己基取代的多锗烷的合成结果最好，相对高产率（25-45%）、高电流效率（25-50%）、高分子量（Mw：10，000 - 25，000）和长吸收最大值（λmax：324-327 nm）。由此获得的聚锗烷显示出已知的聚合物的不连续的热致变色变化。在相同条件下合成相应的聚硅烷得到了更好的产率（50-70%）、更好的电流效率（50-80%）、略大的分子量（Mw：15，000 - 35，000）、但更短的吸收峰（λmax：313-316 nm）。对反应机理进行了详细的讨论。在讨论中提出，在电解的后期阶段发生更多的反咬反应，这是产率和分子量降低的原因之一。为了知道分子量和产率是否在电聚合的后期阶段降低，进行了具有理论值的40%、60%、80%和100%电的合成。以理论电量的80%合成效果最好。
Five dialkyl-substituted and three phenyl substituted polygermanes were electrochemically synthesized. Among them, dibutyl-, dipentyl-, and dihexyl-substituted polygermanes gave the best synthetic results, i.e., relatively high yields (25–45%), high current efficiency (25–50%), high molecular weights (Mw: 10,000–25,000), and long absorption maxima (λmax: 324–327 nms). Thus obtained polygermanes showed the discontinuous thermochromic changes known for the polymers. Syntheses of the corresponding polysilanes under the same conditions gave better yields (50–70%), better current efficiency (50–80%), slightly larger molecular weights (Mw: 15,000–35,000), but shorter absorption maxima (λmax: 313–316 nms). The reaction mechanism was discussed in detail. It was suggested in the discussion that more back-biting reactions, which is one of the causes for the decrease of the yield and the molecular weight, occur in the later stages of electrolysis. In order to know if molecular weights and yields are decreasing in the later stages of electropolymerization, syntheses with 40, 60, 80, and 100% electricity of the theoretical value were carried out. Synthesis with 80% electricity of the theoretical value gave the best results.