Photo- and Vapor-Controlled Luminescence of Rhombic Dicopper(I) Complexes Containing Dimethyl Sulfoxide
Photo- and Vapor-Controlled Luminescence of Rhombic Dicopper(I) Complexes Containing Dimethyl Sulfoxide
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DOI：
10.1021/ic402104q
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发表时间：
2013-11-18
影响因子：
4.6
通讯作者：
Kato, Masako
中科院分区：
文献类型：
--
作者：
Kobayashi, Atsushi;Komatsu, Kahori;Kato, Masako
合成了卤原子桥联的菱形双铜（I）配合物[Cu-2（mu-X）（2）（DMSO）（2）（PPh 3）（2）]（X = I-，Br-; DMSO =二甲基亚砜; PPh 3 =三苯基膦），其碘化物配合物在固态下通过光照射和DMSO蒸气照射显示出有趣的光致变色发光。单晶X射线衍射分析表明，碘代和溴代配合物（简称Cu 2 I2-[O，O]和Cu 2Br 2-[O，O]）是类质同象的，两个DMSO配体都通过O原子与Cu（I）离子配位.两种配合物在室温下均显示出明亮的蓝色磷光（λ（em）= 435 nm，对于Cu 2 I2 [O，O]和Cu 2Br 2-[O，O]，Phi（em）= 0.19和0.14，分别）具有相对长的发射寿命（τ（em）在77 K下类似于200 μ s），其源自混合的卤化物-配体和金属-配体电荷转移（（XLCT）-X-3和（MLCT）-X-3）。M-3）激发态。在紫外光照射下，Cu_2Br_2-[O，O]的蓝色磷光平稳消失，没有新的发射带出现，而Cu_2 I_2-[O，O]的蓝色磷光迅速消失，同时出现一个新的绿色发射带（λ（em）= 500 nm）。在进一步照射时，碘化物络合物的绿色发射逐渐变为明亮的黄绿色（λ（em）= 540 nm）;然而，这种变化可以通过将温度降低至263 K或在饱和DMSO蒸气的存在下完全抑制。Cu 2 I2-[O，O]的初始蓝色磷光通过在90 ℃下暴露于DMSO蒸气几小时来恢复。红外光谱和理论计算表明，DMSO配体发生了从O-配位到S-配位的键异构化，键异构化的发生和DMSO的去除都导致了菱形Cu 2 O 4-O-2核的收缩，使Cu. Cu相互作用更有效。在收缩核中，通过（XLCT）-X-3和（MLCT）-M-3混合过渡态的热激发，容易产生以团簇为中心的三重态（（CC）-C-3）发射态，导致绿色至黄绿色发射。与此相反，在Cu 2Br 2-[O，O]中的Cu“Cu距离比在Cu 2 I2 [O，O]中的Cu“Cu距离长得多，这使（CC）-C-3发射态不稳定，导致非发射特性。
Halide-bridged rhombic dicopper(I) complexes, [Cu-2(mu-X)(2)(DMSO)(2)(PPh3)(2)] (X = I-, Br-; DMSO = dimethyl sulfoxide; PPh3 = triphenylphosphine), were synthesized, the iodide complex of which exhibited interesting photochromic luminescence driven by photoirradiation and by exposure to DMSO vapor in the solid state. Single-crystal Xray diffraction measurements revealed that the iodo and bromo complexes (abbreviated Cu2I2-[O,O] and Cu2Br2-[O,O]) were isomorphous, and that the two DMSO ligands were coordinated to the Cu(I) ion via the O atom in both complexes. Both complexes exhibited bright blue phosphorescence at room temperature (lambda(em) = 435 nm, Phi(em) = 0.19 and 0.14 for Cu2I2[O,O] and Cu2Br2-[O,O], respectively) with a relatively long emission lifetime (tau(em) similar to 200 mu s at 77 K) derived from the mixed halide-to-ligand and metal-to-ligand charge transfer ((XLCT)-X-3 and (MLCT)-M-3) excited state. Under UV irradiation, the blue phosphorescence of Cu2Br2-[O,O] disappeared uneventfully and no new emission band appeared, whereas the blue phosphorescence of Cu2I2-[O,O] rapidly disappeared with simultaneous appearance of a new green emission band (lambda(em) = 500 nm). On further irradiation, the green emission of the iodide complex gradually changed to bright yellowish-green (lambda(em) = 540 nm); however, this change could be completely suppressed by lowering the temperature to 263 K or in the presence of saturated DMSO vapor. The initial blue phosphorescence of Cu2I2-[O,O] was recovered by exposure to DMSO vapor at 90 degrees C for a few hours. IR spectroscopy and theoretical calculations suggest that the DMSO ligand underwent linkage isomerization from O-coordination to S-coordination, and both the occurrence of linkage isomerization and the removal of DMSO result in contraction of the rhombic Cu2O4-O-2 core to make the Cu.-Cu interaction more effective. In the contracted core, the triplet cluster-centered ((CC)-C-3) emissive state is easily generated by thermal excitation of the (XLCT)-X-3 and (MLCT)-M-3 mixed transition state, resulting in the green to yellowish-green emission. In contrast, the Cu"Cu distance in Cu2Br2-[O,O] is considerably longer than that of Cu2I2[O,O], which destabilizes the (CC)-C-3 emissive state, resulting in the nonemissive character.