González Enzo, González Alexis F, Mariman Andrea P, Jara Camilo I, Velázquez Joel D, Saldías César, Schott Eduardo, Zarate Ximena, Tundidor-Camba Alain, Sobarzo Patricio A, Terraza Claudio A
Research Laboratory for Organic Polymers, Faculty of Chemistry and of Pharmacy, Pontificia Universidad Católica de Chile, P.O. Box. 306, Post 22, Santiago PC. 7820436, Chile.
Department of Physical Chemistry, Pontificia Universidad Católica de Chile, Santiago PC. 7820436, Chile.
Polymers (Basel). 2025 May 12;17(10):1316. doi: 10.3390/polym17101316.
Four silane-containing Schiff base oligomers (o-SBNs and o-SBBs) were synthesized by high-temperature polycondensation reactions using silicon-based dialdehydes with naphthalene and 1,1'-binaphthalene diamine derivates. The samples showed a moderate solubility in common organic solvents, where the incorporation of TPS cores into o-SBN2 allows the formation of highly soluble material in non-polar solvents with higher molecular weights (11.58 kDa) and polydispersity. All oligo-SBs displayed high thermal resistance (above 450 °C), showing enhanced thermal stability for TPS-containing oligomers, with the degradation temperature exceeding 530 °C (o-SBB2) and high T values due to the higher aromatic content granted by TPS and 1,1'-binaphthalene moieties. Optical results of the oligo-SBs showed broad absorption and emission behavior in the visible spectrum, ranging from deep blue (o-SBN1 and o-SBB1) to blue (o-SBN2 and o-SBB2). The structure promotes a clear bathochromic shift for TPS-based oligomers, attributed to an extended π-conjugation across the backbone. In addition, the π-π overlap effect highlights larger Stokes shifts for the DMS core oligomers o-SN2 (133 nm) and o-SBB1 (195 nm). The oligo-SBs were found to be wide-bandgap materials, with E values in the range of 2.60 eV to 3.67 eV. The higher molecular weight of o-SBN2, which provided an extended π-conjugation, allows the lowest value of E (2.60 eV) to be achieved. In addition, DFT, TDDFT and EDDM calculations were performed on trimeric oligo-SBs, revealing that HOMOs are localized in the amine-terminal fraction, while LUMOs are localized over the terminal aldehyde groups. These findings highlight the used DMS and TPS cores in Schiff base materials, providing valuable insights into fine-tuning physicochemical properties through the use of suitable building blocks and their potential as optoelectronic materials.
通过高温缩聚反应，使用含硅二醛与萘和1,1'-联萘二胺衍生物合成了四种含硅烷的席夫碱低聚物（o-SBNs和o-SBBs）。这些样品在常见有机溶剂中具有适度的溶解性，其中将TPS核引入o-SBN2可形成在非极性溶剂中具有更高分子量（11.58 kDa）和多分散性的高溶解性材料。所有低聚席夫碱都表现出高耐热性（高于450°C），含TPS的低聚物显示出增强的热稳定性，降解温度超过530°C（o-SBB2），并且由于TPS和1,1'-联萘部分赋予的较高芳香族含量而具有高T值。低聚席夫碱的光学结果表明，在可见光谱中具有宽吸收和发射行为，范围从深蓝色（o-SBN1和o-SBB1）到蓝色（o-SBN2和o-SBB2）。该结构促进了基于TPS的低聚物的明显红移，这归因于主链上扩展的π共轭。此外，π-π重叠效应突出了DMS核低聚物o-SN2（133 nm）和o-SBB1（195 nm）的更大斯托克斯位移。发现低聚席夫碱是宽带隙材料，E值在2.60 eV至3.67 eV范围内。提供扩展π共轭的o-SBN2的较高分子量使得能够实现最低的E值（2.60 eV）。此外，对三聚体低聚席夫碱进行了DFT、TDDFT和EDDM计算，结果表明最高占据分子轨道（HOMOs）位于胺端部分，而最低未占据分子轨道（LUMOs）位于末端醛基上。这些发现突出了席夫碱材料中使用的DMS和TPS核，为通过使用合适的结构单元微调物理化学性质及其作为光电子材料的潜力提供了有价值的见解。
