title: Neutral cuprous complexes as ratiometric oxygen gas sensors.
abstract: Four neutral mononuclear Cu(I) complexes, [Cu(pyin)(PPh(3))(2)] (1a), [Cu(pyin)(DPEphos)] (1b), [Cu(quin)(PPh(3))(2)] (2a) and [Cu(quin)(DPEphos)] (2b) (Hpyin = 2-(2-pyridyl)indole, Hquin = 2-(2-quinolyl)indole and DPEphos = bis(2-(diphenylphosphino)phenyl)ether) have been synthesized. X-Ray crystal structure analysis revealed that the central Cu(I) ion in all complexes is in a distorted tetrahedral coordination environment. All four complexes display the typical metal-to-ligand charge transfer (MLCT) absorption band at 371, 363, 413 and 402 nm, respectively. No emission was observed from any complexes in the solid state due to triplet-triplet annihilation. However, the complexes show unusual dual-emission originating from intraligand charge-transfer (ILCT) and MLCT transitions, when dispersed in a rigid matrix (e.g. PMMA) or in frozen CH(2)Cl(2). The oxidation potential of Cu(I)/Cu(II) in these neutral complexes, ∼0.5 V (vs. Ag/AgCl), is lower than those of cationic Cu(I) complexes. Films containing 10 wt% of these complexes in PMMA shows ratiometric fluorescent oxygen gas sensing property with a response ratio of 0.3-3.2 and response time of 3-4 s. Complex 2b acts as a ratiometric oxygen gas sensor with good reversibility through energy and electron transfer mechanisms under the loss of a counteranion.
authors: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, PR China.
authors: Xiaohui
authors: X
authors: Liu
authors: Wei
authors: W
authors: Sun
authors: Luyi
authors: L
authors: Zou
authors: Zhiyuan
authors: Z
authors: Xie
authors: Xiao
authors: X
authors: Li
authors: Canzhong
authors: C
authors: Lu
authors: Lixiang
authors: L
authors: Wang
authors: Yanxiang
authors: Y
authors: Cheng
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis* / Q000737:chemistry
chemical_list: D009942:Organometallic Compounds; D003300:Copper; D010100:Oxygen