Light-Sensitive and Recoverable N-Heterocyclic Carbene Copper(I) Complex in Homogeneous Catalysis
作者:Guodong Zhang、Rui Lang、Wenlong Wang、Hui Lv、Liyuan Zhao、Chungu Xia、Fuwei Li
DOI:10.1002/adsc.201401140
日期:2015.3.23
The synthesis of a light‐responsive N‐heterocycliccarbenecopper(I) complex by introducing a nitrobenzospiropyran unit into the carbene ligand was developed. The solubility of this complex was controlled through reversible conversion between its netural and ionic states using ultraviolet light irradiation. Taking advantage of such a light‐sensitive property facilitated its recovery and reuse in copper(I)‐catalyzed
The first systems associating in a single molecule polyoxotungstates (POTs) and photochromic organic groups have been elaborated. Using the (TBA)(4)[PW11O39Sn(C6H4I)}] precursor, two hybrid organic inorganic species where a spiropyran derivative (SP) has been covalently grafted onto a PW11Sn} fragment via a Sonogashira coupling have been successfully obtained. Alternatively, a complex containing a silicotungstate PW11Si2} unit connected to two spiropyran entities has been characterized. The purity of these species has been assessed using several techniques, including H-1 and P-31 NMR spectroscopy, mass spectrometry, and electrochemical measurements. The optical properties of the hybrid materials have been investigated both in solution and in the solid state. These studies reveal that the grafting of SPs onto POTs does not significantly alter the photochromic behavior of the organic chromophore in solution. In contrast, these novel hybrid SP POT materials display highly effective solid-state photochromism from neutral SP molecules initially nonphotochromic in the crystalline state. The photoresponses of the SP POT systems in the solid state strongly depend on the nature and the number of grafted SP groups.