铕（III）与六甲基磷酰三胺（HMPA）和三苯基氧化膦（TPPO）配合物的光学性质和电子结构

Optical properties and electronic structure of Eu(III) complexes with HMPA and TPPO.

作者信息

Shurygin A V, Vovna V I, Korochentsev V V, Mirochnik A G, Kalinovskaya I V, Sergienko V I

机构信息

Far Eastern Federal University, 8 Sukhanova St., Vladivostok, Russia.

出版信息

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Apr 5;250:119397. doi: 10.1016/j.saa.2020.119397. Epub 2020 Dec 30.

DOI:10.1016/j.saa.2020.119397

PMID:33422875

Abstract

Two adducts of Eu(III) tris-hexofluoroacetylacetonate with HMPA (OP(N(CH)), hexamethylphosphotriamide) and TPPO (OP(CH), triphenylphosphine oxide) were studied by optical spectroscopy and quantum chemistry (DFT/TD-DFT). The structure of the higher occupied molecular orbitals (MO) of the two adducts determines differences in the position of the excitation band maximum of hfac ligands. According to the calculation data, all excited states are caused by the transition to 3 vacant π* MOs of hfac ligands. Optical spectra of absorption, excitation and luminescence are obtained and interpreted. The peculiarity of the HOMO-LUMO structure, the low value of the energy gap, and the broadened absorption region of hfac ligands compensate the low absorbance ability of the groups N(CH) in a region of 220-360 nm for the adduct Eu(hfac)(HMPA), reducing the luminescence intensity by only 5-10% relative to the adduct of the Eu(III) complex with TPPO ligands.

摘要

通过光谱学和量子化学（密度泛函理论/含时密度泛函理论）研究了铕（III）三（六氟乙酰丙酮）与六甲基磷酰胺（HMPA，OP(N(CH₃)₃)）和三苯基氧化膦（TPPO，OP(C₆H₅)₃）形成的两种加合物。两种加合物的最高占据分子轨道（MO）结构决定了六氟乙酰丙酮配体激发带最大值位置的差异。根据计算数据，所有激发态均由向六氟乙酰丙酮配体的3个空π*分子轨道的跃迁引起。获得并解释了吸收光谱、激发光谱和发光光谱。对于加合物Eu(hfac)₃(HMPA)，最高占据分子轨道-最低未占据分子轨道（HOMO-LUMO）结构的特殊性、低能隙值以及六氟乙酰丙酮配体加宽的吸收区域弥补了N(CH₃)₃基团在220 - 360 nm区域的低吸收能力，相对于铕（III）配合物与三苯基氧化膦配体形成的加合物，发光强度仅降低5 - 10%。