TY - JOUR
T1 - Photo- and vapor-controlled luminescence of rhombic dicopper(I) complexes containing dimethyl sulfoxide
AU - Kobayashi, Atsushi
AU - Komatsu, Kahori
AU - Ohara, Hiroki
AU - Kamada, Waka
AU - Chishina, Yuko
AU - Tsuge, Kiyoshi
AU - Chang, Ho Chol
AU - Kato, Masako
PY - 2013/11/18
Y1 - 2013/11/18
N2 - Halide-bridged rhombic dicopper(I) complexes, [Cu2(μ-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 X-ray diffraction measurements revealed that the iodo and bromo complexes (abbreviated Cu2I 2-[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 (λem = 435 nm, Φem = 0.19 and 0.14 for Cu2I2-[O,O] and Cu2Br2-[O,O], respectively) with a relatively long emission lifetime (τem ∼ 200 μs at 77 K) derived from the mixed halide-to-ligand and metal-to-ligand charge transfer (3XLCT and 3MLCT) 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 (λem = 500 nm). On further irradiation, the green emission of the iodide complex gradually changed to bright yellowish-green (λem = 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 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 Cu2(μ-I)2 core to make the Cu···Cu interaction more effective. In the contracted core, the triplet cluster-centered (3CC) emissive state is easily generated by thermal excitation of the 3XLCT and 3MLCT 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 3CC emissive state, resulting in the nonemissive character.
AB - Halide-bridged rhombic dicopper(I) complexes, [Cu2(μ-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 X-ray diffraction measurements revealed that the iodo and bromo complexes (abbreviated Cu2I 2-[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 (λem = 435 nm, Φem = 0.19 and 0.14 for Cu2I2-[O,O] and Cu2Br2-[O,O], respectively) with a relatively long emission lifetime (τem ∼ 200 μs at 77 K) derived from the mixed halide-to-ligand and metal-to-ligand charge transfer (3XLCT and 3MLCT) 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 (λem = 500 nm). On further irradiation, the green emission of the iodide complex gradually changed to bright yellowish-green (λem = 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 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 Cu2(μ-I)2 core to make the Cu···Cu interaction more effective. In the contracted core, the triplet cluster-centered (3CC) emissive state is easily generated by thermal excitation of the 3XLCT and 3MLCT 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 3CC emissive state, resulting in the nonemissive character.
UR - http://www.scopus.com/inward/record.url?scp=84888087155&partnerID=8YFLogxK
U2 - 10.1021/ic402104q
DO - 10.1021/ic402104q
M3 - 学術論文
C2 - 24187915
AN - SCOPUS:84888087155
SN - 0020-1669
VL - 52
SP - 13188
EP - 13198
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 22
ER -