Department of Chemistry, Assam University, Silchar 788011, Assam (India), Fax: (+91) 03842-270342.
Chemistry. 2013 Sep 23;19(39):13151-9. doi: 10.1002/chem.201301666. Epub 2013 Aug 12.
A novel photoluminescent room-temperature liquid-crystalline salicylaldimine Schiff base with a short alkoxy substituent and a series of lanthanide(III) complexes of the type [Ln(LH)3(NO3)3] (Ln = La, Pr, Sm, Gd, Tb, Dy; LH = (E)-5-(hexyloxy)-2-[{2-(2-hydroxyethylamino)ethylimino]methyl}phenol) have been synthesized and characterized by FTIR, (1)H and (13)C NMR, UV/Vis, and FAB-MS analyses. The ligand coordinates to the metal ions in its zwitterionic form. The thermal behavior of the compounds was investigated by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The ligand exhibits an enantiotropic hexagonal columnar (Col(h)) mesophase at room temperature and the complexes show an enantiotropic lamellar columnar (Col(L)) phase at around 120 °C with high thermal stability. Based on XRD results, different space-filling models have been proposed for the ligand and complexes to account for the columnar mesomorphism. The ligand exhibits intense blue emission both in solution and in the condensed state. The most intense emissions were observed for the samarium and terbium complexes, with the samarium complex glowing with a bright-orange light (ca. 560-644 nm) and the terbium complex emitting green light (ca. 490-622 nm) upon UV irradiation. DFT calculations performed by using the DMol3 program at the BLYP/DNP level of theory revealed a nine-coordinate structure for the lanthanide complexes.
一种具有短烷氧基取代基的新型室温磷光液态晶水杨醛亚胺希夫碱及其一系列镧系（III）配合物[Ln（LH）3（NO3）3]（Ln=La、Pr、Sm、Gd、Tb、Dy；LH=（E）-5-（己氧基）-2-[{2-（2-羟乙基氨基）乙基亚氨基}甲基]苯酚）已经被合成并通过 FTIR、（1）H 和（13）C NMR、UV/Vis 和 FAB-MS 分析进行了表征。配体以其两性离子形式与金属离子配位。通过偏光显微镜（POM）和差示扫描量热法（DSC）研究了化合物的热行为。该配体在室温下呈现各向异性六方柱状（Col（h））介晶相，而配合物在约 120°C 时呈现各向异性层状柱状（Col（L））相，具有较高的热稳定性。基于 XRD 结果，提出了不同的空间填充模型来解释配体和配合物的柱状介晶性。配体在溶液和凝聚态中均表现出强烈的蓝色发射。在 Sm 和 Tb 配合物中观察到最强的发射，其中 Sm 配合物发出明亮的橙色光（约 560-644nm），Tb 配合物发出绿色光（约 490-622nm），在 UV 照射下。通过在 BLYP/DNP 理论水平上使用 DMol3 程序进行的 DFT 计算表明，镧系配合物具有九配位结构。
