Emission Properties of Eu(III) Complexes Containing Arsine and Phosphine Ligands with Annulated Structures

Abstract

In this study, we synthesized Eu 3+ complexes containing arsine and phosphine oxides with annulated structures as the antenna ligands. The type of bridging in the annulated structures controlled the energy level of the triplet excited state and the intersystem crossing efficiency, leading to different emission properties. Eu 3+ complexes bearing the arsine oxides showed a higher intensity ratio of electric/magnetic dipole transitions and energy-transfer efficiency than the complexes with the corresponding phosphine oxides.

Intensive emission of Eu(iii) β-diketonate complexes with arsine oxide ligands

“…Furthermore, the k r values of the Eu(hfa) 3 complexes were significantly greater than those of the ethanol-free Eu(NO 3 ) 3 complexes (phenoxybenzene type) that we previously reported. 7 On the other hand, a slight increase in k nr was also observed as a result of vibrations caused by the C–H bonds of the hfa ligands. 8…”

“…6 We also studied the use of annulated arsine oxide ligands for luminescent Eu 3+ complexes and established a correlation between the ligand structure and photophysical properties of the ensuing Eu 3+ complexes. 7 In these investigations involving arsine oxide ligands, nitrate anion (NO 3 À ) served as the counter anion for the Eu 3+ cation. Because NO 3 À does not significantly impact the energy transfer between the arsine oxide ligand and Eu 3+ core, it is an optimal choice for studying the photophysical characteristics of arsine oxide ligands.…”

“…6 We also studied the use of annulated arsine oxide ligands for luminescent Eu 3+ complexes and established a correlation between the ligand structure and photophysical properties of the ensuing Eu 3+ complexes. 7…”

Syntheses and Photophysical Properties of Pnictogen‐ and Chalcogen‐Containing Diheteroanthracenes

“…The lone pairs of Pn atoms are sp 1.05 -and sp 1. 16 -(1 and 4), sp 0.66 -(2 and 5), and sp 0.48 -and sp 0.49hybridized (3 and 6) (Table S20). [2b,11] This is accepted even for ladder-type compounds because the s-character of the lone pair is related to the sum of the bond angles around the Pn atom.…”

“…Chloroform (CHCl 3 ), dichloromethane (CH 2 Cl 2 ), methanol (MeOH), ethanol (EtOH), tetrahydrofuran (THF), n ‐hexane, ethylacetate (EtOAc), hydrogen peroxide (H 2 O 2 , 30% aqueous solution), sodium sulfonate anhydrous (Na 2 SO 4 ), tetramethylethylenediamine (TMEDA), antimony trichloride (SbCl 3 ), and dichlorophenylphosphine (PhPCl 2 ) were purchased from Nacalai Tesque, Inc. Superdehydrated diethyl ether (stabilizer free) (Et 2 O), distilled water, n ‐butyllithium solution ( n ‐BuLi, 1.6 M in n ‐hexane), magnesium sulfate anhydrous (MgSO 4 ), and iodine (I 2 ) were purchased from Wako Pure Chemical Industry, Ltd. Phenyl sulfide, phenyl ether and triphenylstibine were purchased from Tokyo Chemical Industry Co., Ltd. Diidophenylarsine, [4a] dichlorostibine, [14] 10‐phenyl‐10H‐phenoxaphosphine ( 1 ), [15] 10‐phenyl‐10H‐phenoxarsiine ( 2 ), [16] 10‐phenyl‐10H‐phenoxaphosphine oxide ( 9 ), [16] 10‐phenyl‐10H‐phenoxarsine oxide ( 10 ), [16] 10‐phenyl‐10H‐phenothiaphosphine‐5,5‐dioxide, [11] 10‐phenyl‐10H‐phenothiarsine‐5,5‐dioxide [11] were prepared according to literature procedures.…”