Platinum(II) coordination compound with 4′-[4-(dimethylamino)phenyl]-2, 2′:6′, 2″-terpyridine – The new insight into the luminescence behavior and substituent effect. (15th May 2020)

• Record Type: Journal Article
• Authors: Maroń, Anna M.; Choroba, Katarzyna; Małecki, Jan G.; Kula, Slawomir; Malicka, Ewa
• Is Part Of: Polyhedron. Volume 182(2020)
• Publication Date: 2020-05-15
• Subjects: Platinum(II) coordination compounds -- 4′-Substituted 2, 2′:6′, 2″-terpyridine -- Photoluminescence -- Substituent effect; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2020.114502
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: {PtCl[4′-(4-NMe2 )-Ph-terpy-κ 3 N]}BPh4 ·CH3 CN was synthesized and its structural, electrochemical and photophysical properties were characterized in comparison to previously described systems of [PtCl(4′-Ph-terpy-κ 3 N)] + and [PtCl(4′-NMe2 -terpy-κ 3 N)] + . Abstract: {PtCl[4′-(4-NMe2 )-Ph-terpy-κ 3 N]}BPh4 ·CH3 CN (1 ) was synthesized and its structural, electrochemical and photophysical properties were characterized in comparison to previously described systems of [PtCl(4′-Ph-terpy-κ 3 N)] + and [PtCl(4′-NMe2 -terpy-κ 3 N)] + to determine again the significance of the appropriate design of substituent in case of luminescence behavior of transition metal complex. The molecular formula of compound was confirmed by. X-ray analysis, elemental analysis, FT-IR and NMR studies. The geometries of ground and excited states of compound were also calculated on the basis of Density Functional Theory (DFT) method. The electrochemical properties were elucidated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electronic absorption spectra of compound (1 ) in solutions are similar to those in described previously platinum(II) terpyridine coordination compounds. The photoluminescence properties were studied in various media to rationalize effects on emission properties caused by substituent, solvent polarity, concentration of solution and rigidity of media. The studied compound displays enhancement of photoluminescence properties in comparison to [PtCl(terpy-κ 3 N)] + system, however its emission lifetime in the regard to [PtCl(4′-Ph-terpy-κ 3 N)] + and [PtCl(4′-NMe2 -terpy-κ 3 N)] + is significantly decreased. This suggest the impeded charge transfer from electron-rich NMe2 group via phenylene bridge to the terpy core due to the unfavorable, inclined geometry of excited state. As a consequence of substituent twisting on the path S0 → S1 → T1, the interference of 3 ILCT and 3 MLCT excited state is disturbed favouring the non-radiative deactivation process of {PtCl[4′-(4-NMe2 )-Ph-terpy-κ 3 N]}BPh4 ·CH3 CN.