中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | 34,34-dimethyl-24,29,39,44-tetraoxa-9,12-diazanonacyclo[43.2.2.220,23.230,33.235,38.16,10.111,15.02,7.014,19]heptapentaconta-1(47),2,4,6(57),7,9,11(56),12,14,16,18,20,22,30,32,35,37,45,48,50,52,54-docosaene | —— | C53H48N2O4 | 776.975 |
—— | 35,35-dimethyl-24,27,30,40,43,46-hexaoxa-9,12-diazanonacyclo[45.2.2.220,23.231,34.236,39.16,10.111,15.02,7.014,19]nonapentaconta-1(49),2,4,6(59),7,9,11(58),12,14,16,18,20,22,31,33,36,38,47,50,52,54,56-docosaene | 950823-68-4 | C53H48N2O6 | 808.974 |
This report describes photoluminescence studies of copper-containing [2]pseudorotaxanes that mimic elements of functioning molecular machines. Excitation with visible light induces a formal oxidation of the metal center and simulates an actuation process. In all four [2]pseudorotaxanes studied, the ring ligand is the same, but the thread ligand is variable, namely 2,9-di(anisol-4-yl)-1,10-phenanthroline (dap), 6,6′-di(anisol-4-yl)-2,2′-bipyridine (o-dabipy), 5,5′-di(anisol-4-yl)-2,2′-bipyridine (m-dabipy), or 8,8′-di(anisol-4-yl)-3,3′-bi-isoquinoline (dabiiq). The absorbance bandshapes suggest that aryl substituents extending from the core ligands engage in stacking interactions and induce a partially flattened structure in the ground state. More severe flattening occurs in the excited state and precludes the observation of emission if inter-ligand steric forces do not limit the distortion. Thus, the [2]pseudorotaxanes containing dap or o-dabipy as the thread ligand exhibit uncorrected emission maxima at around 720 nm in room-temperature dichloromethane, while the less constrained analogues, containing dabiiq or m-dabipy, are not emissive in fluid solution and barely exhibit a signal in rigid media. In dichloromethane, the luminescence quantum yields of the dap- and o-dabipy-containing systems are 6 × 10−4 and 4 × 10−4, and the excited-state lifetimes are 98 ns and 90 ns, respectively.