Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
J Am Chem Soc. 2012 Jun 27;134(25):10607-20. doi: 10.1021/ja3036515. Epub 2012 Jun 12.
A series of endohedral and exohedral amine-functionalized ligands were synthesized and used in the construction of supramolecular D(2h) rhomboids and a D(6h) hexagon. These supramolecular polygons were obtained via self-assembly of 120° dipyridyl donors with 180° or 120° diplatinum precursors when combined in 1:1 ratios. Steady-state absorption and emission spectra were collected for each ligand and metallacycle. Density functional theory (DFT) and time-dependent DFT calculations were employed to probe the nature of the observed optical transitions for the rhomboids. The emissive properties of these bis(phosphine) organoplatinum metallacycles arise from ligand-centered transitions involving π-type molecular orbitals with modest contributions from metal-based atomic orbitals. The D(2h) rhomboid self-assembled from 2,6-bis(4-pyridylethynyl)aniline and a 60° organoplatinum(II) acceptor has a low-energy excited state in the visible region and emits above 500 nm, properties which greatly differ from those of the parent 2,6-bis(4-pyridylethynyl)aniline ligand.
一系列的笼型和笼外胺官能化配体被合成，并用于构建超分子 D(2h)菱形和 D(6h)六边形。这些超分子多形体是通过 120°二吡啶供体与 180°或 120°二铂前体在 1:1 比例下自组装得到的。对每个配体和金属络合物都收集了稳态吸收和发射光谱。密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）计算用于探究菱形的观察到的光跃迁的性质。这些双（膦）有机铂金属络合物的发光性质源于涉及π型分子轨道的配体中心跃迁，其中金属基原子轨道有适度的贡献。由 2,6-双（4-吡啶基乙炔基）苯胺和 60°有机铂（II）受体自组装的 D(2h)菱形具有在可见光区域的低能量激发态，并在 500nm 以上发射，这些性质与母体 2,6-双（4-吡啶基乙炔基）苯胺配体有很大的不同。
