title: Highly efficient sensitized red emission from europium (III) in Ir-Eu bimetallic complexes by 3MLCT energy transfer.
abstract: Two novel iridium-europium bimetallic complexes, {[(dfppy)2Ir(mu-phen5f)]3EuCl}Cl2 and (dfppy)2Ir(mu-phen5f)Eu(TFAcA)3 [dfppy represents 2-(4',6'-difluorophenyl)-pyridinato-N,C(2'), phen5f stands for 4,4,5,5,5-pentafluoro-1-(1',10'-phenanthrolin-2'-yl)-pentane-1,3-dionate and TFAcA represents trifluoroacetylacetonate], were successfully synthesized. The novel ligand Hphen5f with four coordination sites was designed as a bridge to link the Ir (III) center and the Eu (III) center. The X-ray diffraction data shows that the nonbonding distances for Eu...Ir are 6.028, 5.907, and 6.100 A in the bimetallic complex {[(dfppy)2Ir(mu-phen5f)]3EuCl}Cl2. Photophysical studies implied that the high efficient red luminescence from the Eu (III) ion was sensitized by the (3)MLCT (metal-to-ligand charge transfer) energy based on an Ir (III) complex-ligand in a d-f bimetallic assembly. The excitation window for the new bimetallic complex {[(dfppy)2Ir(mu-phen5f)]3EuCl}Cl2 extends up to 530 nm (1 x 10(-3) M in EtOH), indicating that this bimetallic complex can emit red light under the irradiation of sunlight.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Chen
authors.forename: Zu-Qiang
authors.initials: ZQ
authors.lastname: Bian
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Liu
authors.forename: Dao-Bo
authors.initials: DB
authors.lastname: Nie
authors.forename: Zhu-Qi
authors.initials: ZQ
authors.lastname: Chen
authors.forename: Chun-Hui
authors.initials: CH
authors.lastname: Huang
mesh_terms: D003116:Color; D018360:Crystallography, X-Ray; D004735:Energy Transfer; D005063:Europium / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010777:Photochemistry; D013053:Spectrophotometry
chemical_list: D007495:Iridium; D005063:Europium