1
|
Hou Z, Huang Y, Ruan Y, Xu H, Tan Y, Lin LR, Wu ZY. Reversible trans-to- cis photoisomerization and irreversible photocyclization reactions of a Co-coordinated stilbene derivative on chiral di-β-diketonate lanthanide complexes. RSC Adv 2023; 13:2269-2282. [PMID: 36741132 PMCID: PMC9837704 DOI: 10.1039/d2ra07133a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Six lanthanide complexes constructed from two chiral β-diketonates (d/l-fbc = 3-heptafluorobutyryl-(+)/(-)-camphorate), the stilbene derivative (E)-N',N'-bis(pyridin-2-ylmethyl)-4-styrylbenzoyl hydrazide (L), a trifluoroacetate anion (CF3CO2 -), and one water molecule, namely [Ln(d/l-fbc)2(L)(CF3CO2)]·H2O (LnC57H54F17N4O8, Ln = La (1, d-fbc), La (2, l-fbc), Sm (3, d-fbc), Eu (4, d-fbc), Eu (5, l-fbc), and Tb (6, d-fbc), were synthesized and characterized by single-crystal X-ray diffraction, 1H-NMR, elemental analysis, IR and UV-vis spectroscopy, and thermal gravimetric analysis. The photoisomerization reactions of these complexes were systematically studied by means of experimental and theoretical calculations. Crystals of complexes 1, 2, 3, and 4 were obtained and belong to the monoclinic crystal system and the C2 chiral space group. The Λ- and Δ-diastereomers coexist in their crystals and no apparent bisignate couplets are observed in their ECD spectra. Among the complexes, the photocyclization reaction is followed by the trans-to-cis photoisomerization reaction and competes with the trans-to-cis photoisomerization, then the photocyclization reaction continues. The photocyclization reaction is irreversible in this stilbene derivative and is delayed in the lanthanide complexes. These results provide a viable strategy for the design of promising new stilbene-attached dual-functional lanthanide-based optical-switching materials.
Collapse
Affiliation(s)
- Ziting Hou
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen UniversityXiamen361005P. R. China
| | - Yanji Huang
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen UniversityXiamen361005P. R. China
| | - Yushan Ruan
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen UniversityXiamen361005P. R. China
| | - Han Xu
- School of Pharmaceutical Science & Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical UniversityKunming650500P. R. China
| | - Yu Tan
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen UniversityXiamen361005P. R. China
| | - Li-Rong Lin
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen UniversityXiamen361005P. R. China
| | - Zhen-yi Wu
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen UniversityXiamen361005P. R. China
| |
Collapse
|
2
|
Cui M, Yang L, Li F, Zhou L, Song Y, Fang SM, Liu CM, Li XL. Multifunctional Dy III Enantiomeric Pairs Showing Enhanced Photoluminescences and Third-Harmonic Generation Responses through the Coordination Role of Homochiral Tridentate N,N,N-Pincer Ligands. Inorg Chem 2021; 60:13366-13375. [PMID: 34428893 DOI: 10.1021/acs.inorgchem.1c01682] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By utilizing Dy(hfac)3(H2O)2 to react with enantiomerically pure tridentate N,N,N-pincer ligands, namely (-)/(+)-2,6-bis(4',5'-pinene-2'-pyridyl)pyridine (LR and LS), respectively, homochiral DyIII enantiomeric pairs formulated as Dy(hfac)3LR/Dy(hfac)3LS (R-1/S-1) (hfac- = hexafluoroacetylacetonate) were achieved and structurally characterized. Meanwhile, their magnetic, photoluminescent (PL), and chiroptical properties were probed. The PL test results indicate that the precursor Dy(hfac)3(H2O)2 only shows very weak emission, while R-1 exhibits characteristic DyIII f-f transition emission bands at room temperature. Furthermore, the nonlinear optical responses of Dy(hfac)3(H2O)2, LR/LS, and R-1/S-1 were investigated in detail based on crystalline samples. The results reveal that LR and LS present the coexistence of second- and third-harmonic generation (SHG and THG) responses with more intense signals for SHG responses; and Dy(hfac)3(H2O)2 merely displays weak THG responses, while R-1 and S-1 also only exhibit THG responses. However, the THG intensities of R-1 and S-1 are more than six times larger than that of Dy(hfac)3(H2O)2 under the identical measurement conditions. These results demonstrate that introducing homochiral N,N,N-pincer ligands to replace two H2O molecules of Dy(hfac)3(H2O)2 results in significant improvements of both PL performances and THG responses of resultant R-1/S-1 enantiomers. R-1 and S-1 integrate PL, THG, and chiral optical activity in one molecule, suggesting their multifunctional merits. In particular, a convenient method is introduced to simultaneously test THG and SHG responses of molecular materials based on crystalline samples in this work.
Collapse
Affiliation(s)
- Minghui Cui
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, PR China
| | - Linpo Yang
- Department of Applied Physics, Harbin Institute of Technology, Harbin 150001, PR China
| | - Fengcai Li
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, PR China
| | - Liming Zhou
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, PR China
| | - Yinglin Song
- Department of Applied Physics, Harbin Institute of Technology, Harbin 150001, PR China
| | - Shao-Ming Fang
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, PR China
| | - Cai-Ming Liu
- Bejing National Laboratory for Molecular Sciences, Institution of Chemistry, Chinese Academy of Sciences, Bejing 100190, PR China
| | - Xi-Li Li
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, PR China
| |
Collapse
|
3
|
Li M, Zhou Y, Yao Y, Gao T, Yan P, Li H. Designing water-quenching resistant highly luminescent europium complexes by regulating the orthogonal arrangement of bis-β-diketone ligands. Dalton Trans 2021; 50:9914-9922. [PMID: 34223568 DOI: 10.1039/d1dt00155h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Luminescent β-diketone-based lanthanide complexes have been well explored as chemical sensor materials for biomedicine applications. Herein, three mononuclear Eu3+ complexes based on bis-β-diketone ligands (L1, L2 and L3) that can reduce luminescence quenching caused by water were developed. The ligands feature two β-diketone units covalently bound at the 1,8-position of the derivatized anthracene (modified with tetracyanoethylene, TCNE). X-ray crystallographic analysis reveals that their self-assemblies with Ln3+ ions in a 2 : 1 stoichiometric ratio form mononuclear anion complexes, [EuL2]-, in which two ligands coordinate to the metal center in a mutually orthogonal manner. This kind of arrangement together with the bulge of TCNE from the anthracene plane well protected the complexes from the quenching effects of water molecules in the second coordination. The photophysical measurements showed that the complexes not only had high luminescence quantum yields (QYs, up to 50-67%) but also presented excellent water-quenching resistant capability.
Collapse
Affiliation(s)
- Mei Li
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education; School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
| | - Yanyan Zhou
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education; School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
| | - Yuan Yao
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education; School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
| | - Ting Gao
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education; School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
| | - Pengfei Yan
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education; School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
| | - Hongfeng Li
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education; School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
| |
Collapse
|
4
|
Kudyakova YS, Slepukhin PA, Ganebnykh IN, Burgart YV, Saloutin VI, Bazhin DN. Functionalized Trifluoromethyl-Containing Lithium β-Diketonate in the Synthesis of Homo- and Heteronuclear Complexes of Rare-Earth Metals. RUSS J COORD CHEM+ 2021. [DOI: 10.1134/s1070328421040059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
5
|
Cui M, Wang AL, Gao CL, Zhou L, Wu T, Fang S, Xiao HP, Li FC, Li XL. Two homochiral Eu III and Sm III enantiomeric pairs showing circularly polarized luminescence, photoluminescence and triboluminescence. Dalton Trans 2021; 50:1007-1018. [PMID: 33355317 DOI: 10.1039/d0dt03576a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Two homochiral EuIII and SmIII tris(β-diketonate) enantiomeric pairs, based on fluorinated β-diketone (Hbtfa) and enantiopure asymmetric N,N'-donor ligands (LR and LS), Λ-Eu(btfa)3LR (R-1-Eu)/Δ-Eu(btfa)3LS (S-1-Eu) and Λ-Sm(btfa)3LR (R-2-Sm)/Δ-Sm(btfa)3LS (S-2-Sm) (btfa- = 4,4,4-trifluoro-1-phenyl-1,3-butanedionate and LR/LS = (-)/(+)-4,5-pineno-2,2'-bipyridine) were synthesized. The electronic circular dichroism (ECD) spectra confirmed their enantiomeric nature. R-1-Eu/S-1-Eu and R-2-Sm/S-2-Sm exhibit intense characteristic emissions of EuIII (red) and SmIII (orange-red) ions both in the solid state and in DCM with long lifetimes and high luminescence quantum yields. For example, the overall quantum yields reach up to 61% and 53% along with very high sensitization efficiency values of 82 and 79 for R-1-Eu in the solid state and in DCM, respectively. Notably, the corresponding values are determined to be 6.5% (solid state) and 3.1% (DCM) for R-2-Sm, which are among the highest quantum yields for rare SmIII tris(β-diketonate) luminescent complexes reported to date. Furthermore, R-1-Eu and R-2-Sm show a strong triboluminescence (TL) phenomenon visible with the naked eye in daylight. Moreover, R-1-Eu/S-1-Eu and R-2-Sm/S-2-Sm show circularly polarized luminescence (CPL) properties. Particularly, the luminescence dissymmetry factors (glum) for R-2-Sm/S-2-Sm are larger than those for R-1-Eu/S-1-Eu despite the fact that SmIII complexes usually show poorer emission than EuIII homologues, which is very rare in the reported EuIII and SmIII CPL-active complexes.
Collapse
Affiliation(s)
- Minghui Cui
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P. R. China.
| | - Ai-Ling Wang
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P. R. China.
| | - Cong-Li Gao
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P. R. China.
| | - Liming Zhou
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P. R. China.
| | - Tao Wu
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 2, 16610 Prague 6, Czech Republic.
| | - Shaoming Fang
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P. R. China.
| | - Hong-Ping Xiao
- School of Chemistry of Materials Engineering, Wenzhou University, Wenzhou 325027, P.R. China.
| | - Feng-Cai Li
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P. R. China.
| | - Xi-Li Li
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P. R. China.
| |
Collapse
|
6
|
Cui M, Wang AL, Liu Y, Xiao H, Li F, Zhou L, Fang S, Li XL. A pair of 2D chiral Ag(i) enantiomers with dual chiral elements: syntheses, structures, and photoluminescent and chiroptical properties. RSC Adv 2020; 10:39359-39365. [PMID: 35515417 PMCID: PMC9057406 DOI: 10.1039/d0ra07237k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 10/21/2020] [Indexed: 11/21/2022] Open
Abstract
In this work, two new enantiopure bis-monodentate N-donor chiral ligands, namely (-)/(+)-2-(4'-pyridyl)-4,5-pinene-pyridine (L R /L S ), have been designed and synthesized. Using L R and L S as bridging ligands to react with AgClO4, a pair of novel 2D chiral Ag(i) enantiomers formulated as [Ag2(L R )2(ClO4)2] n (R-1) and [Ag2(L S )2(ClO4)2] n (S-1) were isolated and characterized. In R-1 and S-1, each Ag(i) ion is bonded by two N atoms from two different chiral L R or L S ligands, leading to the formation of 1D right- or left-handed -L-Ag(i)-L- helical chains. Moreover, two adjacent helical chains are further doubly linked by two monodentate ClO4 - anions through weak Ag-O contacts to form 2D network structures, in which dual chiral elements, i.e., center chirality and helical chirality coexist. Interestingly, each free ligand L R /L S and R-1/S-1 enantiomers show very different ECD spectra in the solid state and in solution, which are correlated to the intermolecular interactions and molecular structures in each state, respectively. Notably, as a representative, R-1 exhibits intense room temperature photoluminescence both in the solid state and in solution with different emission features and mechanisms, while it also shows more intense emission than that of free ligand L R . In particular, R-1 and S-1 represent the first examples of 2D Ag(i) chiral coordination polymers (CCPs) supported by ClO4 - anions, possessing dual chiral elements.
Collapse
Affiliation(s)
- Minghui Cui
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry Zhengzhou 450002 P. R. China
| | - Ai-Ling Wang
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry Zhengzhou 450002 P. R. China
| | - Yingfan Liu
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry Zhengzhou 450002 P. R. China
| | - Hongping Xiao
- College of Chemistry & Material Engineering, Wenzhou University Wenzhou 325035 P. R. China
| | - Fengcai Li
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry Zhengzhou 450002 P. R. China
| | - Liming Zhou
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry Zhengzhou 450002 P. R. China
| | - Shaoming Fang
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry Zhengzhou 450002 P. R. China
| | - Xi-Li Li
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry Zhengzhou 450002 P. R. China
| |
Collapse
|
7
|
Lin LR, Tang HH, Wang YG, Wang X, Fang XM, Ma LH. Functionalized Lanthanide(III) Complexes Constructed from Azobenzene Derivative and β-Diketone Ligands: Luminescent, Magnetic, and Reversible Trans-to-Cis Photoisomerization Properties. Inorg Chem 2017; 56:3889-3900. [DOI: 10.1021/acs.inorgchem.6b02819] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Li-Rong Lin
- Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Hui-Hui Tang
- Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Yun-Guang Wang
- Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Xuan Wang
- Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Xue-Ming Fang
- Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Li-Hua Ma
- Department of Chemistry, College of Science and Computer
Engineering, University of Houston—Clear Lake, 2700 Bay Area Boulevard, Houston, Texas 77058, United States
| |
Collapse
|
8
|
Lin LR, Wang X, Wei GN, Tang HH, Zhang H, Ma LH. Azobenzene-derived tris-β-diketonate lanthanide complexes: reversible trans-to-cis photoisomerization in solution and solid state. Dalton Trans 2016; 45:14954-64. [PMID: 27549432 DOI: 10.1039/c6dt01310d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Novel azobenzene-derived β-diketonates (4,4,5,5,6,6,6-heptafluoro-1-azobenzene-1,3-hexanedione (LA), 4,4,5,5,6,6,6-heptafluoro-1-(4-dimethylamino)azobenzene-1,3-hexanedione (LB)) were designed and their complexes with lanthanide cations (La(3+), Eu(3+), Gd(3+), Yb(3+)) were prepared and characterized by (1)H NMR, FT-IR, and elemental analysis. Three of the complexes were crystallized successfully and identified by X-ray diffraction. It was significant to find that LA showed remarkably reversible trans-to-cis isomerization properties, however, LB, bearing an electron donor compared with LA, slowed down the isomerization to an extent. The presence of Ln(iii) enhanced the reversible trans-to-cis isomerization properties of both LA and LB a little upon photoirradiation in organic solvents, and amazingly increased the fatigue resistance. In addition, the complexes doped in polymethyl methacrylate (PMMA) films produced a similar phenomenon as well as when in solution. Theoretical calculations based on time dependent density functional theory (TD-DFT) were performed for geometry optimization and to determine the excitation energies of LA and LB to gain further insight into the electronic structure of the complexes, and the data were consistent with the experimental results. The excellent reversible photoisomerization properties of the newly designed Ln(iii) complexes can offer important advantages that will help with the further study of these materials to reach their full potential in applications such as molecular switching devices.
Collapse
Affiliation(s)
- Li-Rong Lin
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.
| | | | | | | | | | | |
Collapse
|
9
|
Hao HQ, Chen ZC, Kuang WC, Peng MX. Racemic and homochiral coordination polymers based on carboxylates of different lengths. J COORD CHEM 2015. [DOI: 10.1080/00958972.2015.1058484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Hong-Qing Hao
- School of Chemistry and Environment, Jiaying University, Meizhou, PR China
| | - Zhi-Cong Chen
- School of Chemistry and Environment, Jiaying University, Meizhou, PR China
| | - Wei-Cong Kuang
- School of Chemistry and Environment, Jiaying University, Meizhou, PR China
| | - Meng-Xia Peng
- School of Chemistry and Environment, Jiaying University, Meizhou, PR China
| |
Collapse
|
10
|
Hao HQ, Wang CY, Chen ZC. Two different porous coordination polymers regulated by the conformations of flexible ligands. INORG CHEM COMMUN 2014. [DOI: 10.1016/j.inoche.2014.09.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
11
|
Tian C, Zhang H, Du S. Acentric and chiral heterometallic inorganic–organic hybrid frameworks mediated by alkali or alkaline earth ions: synthesis and NLO properties. CrystEngComm 2014. [DOI: 10.1039/c3ce42419g] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
12
|
Zhang H, Lin P, Shan X, Han L, Du S. Absolute helicity induction: chiral information transfer from metal centre to the framework. CrystEngComm 2014. [DOI: 10.1039/c3ce42157k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
13
|
Kaizaki S, Shirotani D, Sato H. A novel correlation of vibrational circular dichroism spectra with the electronic ground state for Δ-SAPR-8-cesium-tetrakis((+)-heptafluorobutyryl-camphorato)lanthanide(iii) complexes. Phys Chem Chem Phys 2013; 15:9513-5. [DOI: 10.1039/c3cp50509j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
14
|
Di Pietro S, Di Bari L. The structure of MLn(hfbc)4 and a key to high circularly polarized luminescence. Inorg Chem 2012; 51:12007-14. [PMID: 23094785 DOI: 10.1021/ic3018979] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The heterobimetallic complex CsEu[(+)-hfbc](4) (hfbc = 3-heptafluorobutyryl camphorate), prepared by Kaizaki and co-workers, displays the highest ratio of polarization versus total luminescence (measured by the g(lum) factor), i.e., ~85% of the emitted photons at 595 nm are left-circularly polarized. We present a detailed structural analysis in solution, based on paramagnetic nuclear magnetic resonance (NMR), and discuss the possible dynamic processes, where its analogues are involved. We demonstrate that the first coordination sphere is very close to the achiral regular square antiprism (SAPR) with D(4d) symmetry, which rules out the intrinsic dissymmetry of the Eu environment for rationalizing the g(lum). In contrast, the dynamic coupling between the f-f transitions, responsible for the emission, to the ligand-centered π-π* transition at 310 nm displays almost ideal geometry to justify g(lum) and discloses a key to high circularly polarized emission.
Collapse
Affiliation(s)
- Sebastiano Di Pietro
- Dipartimento di Chimica e Chimica Industriale, Via Risorgimento 35, 56126 Pisa, Italy
| | | |
Collapse
|
15
|
Shirotani D, Sato H, Yamanari K, Kaizaki S. Electronic circular dichroism in the 4f–4f transitions of a series of cesium tetrakis (+)-3-heptafluorobutyrylcamphorate Ln(iii) complexes. Dalton Trans 2012; 41:10557-67. [DOI: 10.1039/c2dt30951c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|