Fine-tuning of NHC copper (I) complexes bearing dipyridylamine ligands: application in photoluminescence and LEC devices

(1)

HAL Id: hal-02433977

https://hal-normandie-univ.archives-ouvertes.fr/hal-02433977

Submitted on 13 Jan 2020

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Fine-tuning of NHC copper (I) complexes bearing dipyridylamine ligands: application in

photoluminescence and LEC devices

Margaux Elie, Fabien Sguerra, Florent Di Meo, Michael D. Weber, Ronan Marion, Jean-Luc Renaud, Mathieu Linares, Matthieu Hamel, Sylvain

Gaillard, Rubén D. Costa

To cite this version:

Margaux Elie, Fabien Sguerra, Florent Di Meo, Michael D. Weber, Ronan Marion, et al.. Fine-tuning of NHC copper (I) complexes bearing dipyridylamine ligands: application in photoluminescence and LEC devices: (NHC)Cu(I) Complexes bearing Dipyridylamine ligands : Synthesis, Structural, Photoluminescent Studies and Applications in Luminescent Materials. Organometallic Chemistry Directed Towards Organic Synthesis (OMCOS 18), Jun 2015, Sitges - Barcelona, Spain. �hal-02433977�

(2)

Fine-tuning of NHC Copper (

I

) Complexes bearing Dipyridylamine

Ligands: Application in Photoluminescence and LEC devices.

Margaux ELIE,

1 Fabien SGUERRA,

2 Florent DI MEO,

3 Michael D. WEBER,

4 Ronan MARION,

1 Jean-Luc

RENAUD,

1 Mathieu, LINARES,

3,

* Matthieu HAMEL,

2,

* Rubèn D. COSTA ,

4,

*and Sylvain GAILLARD

1,

*

1

_{LCMT, Normandie University, CNRS, UMR 6507, ENSICAEN, Caen, France}

2

_{CEA, LIST, Saclay, Laboratoire Capteurs et Architectures Electroniques, F-91191, Gif-sur-Yvette Cedex, France}

3

_{Department of Physics, Chemistry and Biology SE-581 83, Linköping University, Sweden}

4

_{Department of Chemistry and Pharmacy at the University of Erlangen-Nuremberg, 91058 Erlangen, Germany}

E-mail: margaux.elie@ensicaen.fr

dpa ligands

---[1] Marion, R.; Sguerra, F.; Di Meo, F.; Sauvageot, E.; Lohier, J.-F.; Daniellou, R.; Renaud J.-L.; Linares, M.; Hamel, M. Gaillard, S. Inorg. Chem. 2014, 53, 9181-9191

[2] Elie, M.; Sguerra, F.; Di Meo, F.; Weber, M. D.; Marion, R.; Grimault, A.; Lohier, J.-F., Renaud, J.-L.; Costa, R. D.; Linares, M.; Hamel, M.; Gaillard, S. (Submitted)

Photophysical Properties

NHC Ligands

 Electronic properties of dpa ligand allows fine-tuning on the emission wavelenghts (emission between 436 to 550 nm).

 TADF phenomenon assessed by the red-shift of the emission at 77K and TD-DFT calculations.

We present the synthesis of new cationic tricoordinated copper complexes bearing bidentate dipyridylamine (dpa) ligands and NHC as ancillary ligands [Cu(NHC)(DPA)][X]. These copper complexes have been fully characterized by NMR, X-ray analysis, electrochemistry, and photophysics. Theoritical calculations were also undergone to rationalize the assignment of the photophysical properties. Some of these copper complexes exhibit very bright blue emission with high quantum yield at solid state. A variation of the electronic properties on both NHC and dipyridylamine ligands, has been carried out and permitted to establish a structure – properties relationship, also supported by DFT and TD-DFT calculations.

Since emissive cationic organometallic complexes can be good candidates for LEC (Light emitting Electrochemical Cells) applications, we presented here the proof of concept that our copper complexes of general formula [Cu(NHC)(dpa)][X] can be applied for LEC devices.[1,2]

CONCLUSION

 Easy and robust syntheses for [Cu(NHC)(dpa)][X] complexes from [CuCl(NHC)] or [CuOH(NHC)].

 _{Tuning of the NHC ligand allows a better quantum yields}

(TD-) DFT calculations (ωB97XD)

Application in LEC

devices

Emission spectra in solid state. Half life time of the excited state between 17 and 51 µs.

400 450 500 550 600 0.0 0.2 0.4 0.6 0.8 1.0 Emis sion [a.u.] Wavelength [nm] cuiprl1n1_RT cuiprl1n1_LT [Cu(IPr)(L1)][PF₆] 298K [Cu(IPr)(L1)][PF₆] 77K

Thermally Activated

Delayed Fluorescence (TADF)

[Cu(NHC)(L1)][PF₆]

(IPr) (Me_{IPr) (IPr}MeO_{) (}Me_IPrMeO₎

[Cu(IPr)(Lx)][PF₆]

(L2) (L3) (L4) (L5) (L6) (L7) (L9)

0.22 0.48 0.31 0.64 0.55 <0.05 <0.05 0.20 0.36 0.86 0.43

quantum yields

(emission in solid state)

Copper complexes under UV radiation (366nm)

Emission spectra in solid state at 298 K and 77 K

Cyclic voltammogram of complex [Cu(IPr)(L1)][PF₆] in

CH₂Cl₂ containing 0.1 M NBu₄PF₆ between -2.0 and 2.5 V.

Scan rate = 0.025 V.s-1

Copper complexes are stable between -1.0 V and 1.7 V

 _{Proof of concept for the use of [Cu(NHC)(dpa)][X] for} the fabrication of LEC devices.

Scan rates: 1.0 V/s 0.5 V/s 0.1 V/s 0.025 V/s

Tuning on NHC:

quantum yields

improvement

Tuning on dpa :

emission wavelenth

modification

[Cu(IPr)(L1)]+ 0.35 [Cu(Me_IPr)(L1)]+ 0.24 [Cu(IPrMeO_)(L1)]+ 0.36

[Cu(Me_IPrMeO_)(L1)]+

0.35 [Cu(Cl_IPr)(L1)]+ 0.29 [Cu(IPr)(L2)]+ 0.36 [Cu(IPr)(L3)]+ 0.37 [Cu(IPr)(L4)]+ 0.12 [Cu(IPr)(L5)]+ 0.36 [Cu(IPr)(L6)]+ 0.24

Calculated ΔE

ST

Absorption – Emission Diagram of

[Cu(IPr)(L1)]+ 400 500 600 700 800 -200 0 200 400 600 800 1000 1200 1400 Coun ts [a .u. ] Wavelength [nm] 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66