Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.
Inorg Chem. 2011 Nov 21;50(22):11736-45. doi: 10.1021/ic201745y. Epub 2011 Oct 26.
A dinuclear organometallic acceptor 4,4'-bis[trans-Pt(PEt(3))(2)(O(3)SCF(3))(ethynyl)]biphenyl (1) containing Pt-ethynyl functionality is synthesized. Multinuclear NMR ((1)H, (31)P, and (13)C), infrared (IR), and electrospray ionization mass spectrometry (ESI-MS) including single-crystal X-ray diffraction analysis established the formation of 1. Equimolar treatment of acceptor 1 separately with three different "clip" type ditopic donors (L(a)-L(c)) yielded [2 + 2] self-assembled three metallamacrocycles 2a-2c, respectively. These macrocycles were characterized by various spectroscopic techniques, and their sizes/shapes were obtained through geometry optimization using molecular mechanics universal force field (MMUFF) simulations. Attachment of unsaturated ethynyl functionality to biphenyl building unit helped to make the macrocycles (2a-2c) π-electron rich and thereby fluorescent in nature. Furthermore, 2c in solution has been examined to be suitable for sensing electron-deficient nitroaromatic like picric acid, which is often considered as a secondary chemical explosive. The fluorescence study of 2c showed a marked quenching of initial emission intensity upon titrating with picric acid (PA), and it exhibited the largest fluorescence quenching response with high selectivity among various other electron deficient aromatic compounds tested.
合成了一种含有 Pt-乙炔基官能团的双核有机金属受体 4,4'-双[反式-Pt(PEt(3))(2)(O(3)SCF(3))(乙炔基)]联苯(1)。多核 NMR((1)H、(31)P 和(13)C)、红外(IR)和电喷雾电离质谱(ESI-MS)，包括单晶 X 射线衍射分析，确定了 1 的形成。分别用三种不同的“夹子”型双位点供体(L(a)-L(c))与受体 1 等摩尔处理，分别得到了[2+2]自组装的三个金属大环 2a-2c。这些大环通过各种光谱技术进行了表征，并通过使用分子力学通用力场(MMUFF)模拟进行几何优化获得了它们的大小/形状。将不饱和乙炔基官能团连接到联苯结构单元上，有助于使大环(2a-2c)具有富π电子的性质，从而具有荧光性质。此外，在溶液中对 2c 进行了检测，发现其对电子缺电子的硝基芳烃（如苦味酸）具有良好的传感性能，苦味酸通常被认为是一种次级化学爆炸物。2c 的荧光研究表明，在与苦味酸（PA）滴定时，初始发射强度明显猝灭，并且在测试的各种其他缺电子芳香族化合物中表现出最大的荧光猝灭响应和高选择性。
