Synthesis, Spectroscopic, and Photophysical Studies of Phosphorescent Bis(2-(2,4-difluorophenyl)pyridine)Iridium(III) Complex Containing Derivative of 1 H -1,2,4-Triazole Anchillary Ligand

Nurul Husna As Saedah Bain; Noorshida Mohd Ali; Yusnita Juahir; Norhayati Hashim; Illyas Md Isa; Azmi Mohamed; Azlan Kamari; Bohari Mohd Yamin

doi:10.22146/ijc.66471

Synthesis, Spectroscopic, and Photophysical Studies of Phosphorescent Bis(2-(2,4-difluorophenyl)pyridine)Iridium(III) Complex Containing Derivative of 1H-1,2,4-Triazole Anchillary Ligand

https://doi.org/10.22146/ijc.66471

Nurul Husna As Saedah Bain⁽¹⁾, Noorshida Mohd Ali^(2*), Yusnita Juahir⁽³⁾, Norhayati Hashim⁽⁴⁾, Illyas Md Isa⁽⁵⁾, Azmi Mohamed⁽⁶⁾, Azlan Kamari⁽⁷⁾, Bohari Mohd Yamin⁽⁸⁾

(1) Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
(2) Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
(3) Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
(4) Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
(5) Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
(6) Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
(7) Department of Chemistry, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia
(8) Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bandar Baru Bangi, Selangor, Malaysia
(*) Corresponding Author

Abstract

A cationic complex of iridium(III), [Ir(2,4-F₂ppy)₂(F₂bpyta)]PF₆ utilizing 1,2,4-triazolepyridyl as an anchillary ligand modified with a 2,6-difluorobenzyl substituent was synthesized and characterized. The aromatic signals of pyridyltriazole and phenylpyridine proton were detected in the ¹H-NMR spectrum between 10.00 and 7.00 ppm. Only one singlet peak was detected at 8.46 ppm H(8) shifted to the upfield, demonstrating that C5 was coordinated to the central iridium metal. The bands exhibited in the range of 1555–1431 cm^–1 in the IR spectrum because of the C=C and C=N aromatic rings stretching pyridine, phenyl, and triazole vibrations. The UV-Vis absorption spectrum showed a slight and broad absorbance peak at lower energy at a l_max = 371 nm (e = 6129 M⁻¹ cm⁻¹) in the visible range due to ¹MLCT and ³MLCT transitions. Blue emission was observed in the steady-state emission spectral of [Ir(2,4-F₂ppy)₂(F₂bpyta)]PF₆ and the other two previously synthesized iridium(III) complexes in CH₂Cl₂ solutions (air-equilibrated) at room temperature. The spectrum of luminescence for the [Ir(2,4-F₂ppy)₂(F₂bpyta)]PF₆ (l_em = 461 nm) is blue-shifted when compared to the [Ir(2,4-F₂ppy)₂(hpyta)]PF₆ (l_em = 469 nm), but red-shifted when related to the [Ir(2,4-F₂ppy)₂(mbpyta)]PF₆ (l_em = 454 nm).

Keywords

iridium(III) complex; 1H-1,2,4-triazole; ancillary ligand

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DOI: https://doi.org/10.22146/ijc.66471