Vilas-Boas M, Freire C, de Castro B, Christensen P A, Hillman A R
CEQUP/Departamento de Química, Faculdade de Ciências, Universidade do Porto, Portugal.
Chemistry. 2001 Jan 5;7(1):139-50. doi: 10.1002/1521-3765(20010105)7:1<139::aid-chem139>3.0.co;2-q.
Electrogenerated polymers based on the nickel(II) complex 2,3-dimethyl-N,N'-bis(salicylidene)butane-2,3-diaminatonickel(II), poly[Ni(saltMe)], were characterised by in situ FTIR and UV/Vis spectroscopy and ex-situ EPR spectroscopy in order to gain insights into film structure, electronic states and charge conduction. The role of the nickel ions during film oxidation was probed by using EPR to study naturally abundant Ni and 61Ni-enriched polymers. The data from all the spectroscopic techniques are consistent, and clearly indicate that polymerisation and redox switching are associated with oxidative ligand based processes; coulometry suggests that one positive charge was delocalised through each monomer unit. EPR provided evidence for the non-direct involvement of the metal in polymer oxidation: the polymer is best described as a polyphenylene-type compound (conducting polymer), rather than an aggregation of nickel complexes (redox polymer), and the main charge carriers are identified as polarons. An explanation for the high electrochemical stability and conductivity of poly[Ni(saltMe)] with respect to that of poly[Ni(salen)] is proposed. based on stereochemical repulsion between monomeric units; this can impose a less compact supramolecular structure on polymers with bulkier substituents.
基于镍（II）配合物2,3-二甲基-N,N'-双（水杨醛）丁烷-2,3-二氨基镍（II）的电生聚合物聚[Ni（saltMe）]，通过原位傅里叶变换红外光谱和紫外/可见光谱以及非原位电子顺磁共振光谱进行表征，以深入了解薄膜结构、电子态和电荷传导。通过使用电子顺磁共振研究天然丰度的镍和富集61Ni的聚合物，探究了镍离子在薄膜氧化过程中的作用。所有光谱技术的数据是一致的，并且清楚地表明聚合和氧化还原切换与基于配体氧化的过程相关；库仑法表明每个单体单元有一个正电荷离域。电子顺磁共振提供了金属不直接参与聚合物氧化的证据：该聚合物最好被描述为聚苯撑型化合物（导电聚合物），而不是镍配合物的聚集体（氧化还原聚合物），并且主要电荷载流子被确定为极化子。基于单体单元之间的立体化学排斥，提出了聚[Ni（saltMe）]相对于聚[Ni（salen）]具有高电化学稳定性和导电性的解释；这会给具有较大取代基的聚合物施加一个较不紧密的超分子结构。
