Coherent Vibration and Femtosecond Dynamics of the Platinum Complex Oligomers upon Intermolecular Bond Formation in the Excited State. (16th November 2020)

• Record Type: Journal Article
• Authors: Iwamura, Munetaka; Fukui, Airi; Nozaki, Koichi; Kuramochi, Hikaru; Takeuchi, Satoshi; Tahara, Tahei
• Is Part Of: Angewandte Chemie. Volume 132:Number 51(2020)
• Page Start: 23354
• Page End: 23361
• Publication Date: 2020-11-16
• Subjects: Femtochemistry -- metal-metal interactions -- oligomerization -- platinum -- time-resolved spectroscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202011813
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Femtosecond time‐resolved absorption and picosecond time‐resolved emission measurements were carried out for highly concentrated aqueous solutions of K2 [Pt(CN)4 ] to investigate excited‐state dynamics of the [Pt(CN)4 2− ] oligomers formed with metallophilic interactions. Time‐resolved absorption spectra exhibit complicated dynamics that are represented with five time constants. Among them, the 90‐ps and 400‐ps dynamics were assigned to the S1 → T1 intersystem crossing of the trimer and tetramer coexisting in the solution by comparison with the fluorescence decays. Clear oscillations of transient absorption were observed in the first few picoseconds, and the frequency‐detected‐wavelength 2D analysis revealed that the 135‐cm −1 and 65‐cm −1 oscillations arise from the Pt–Pt stretch motions of the S1 trimer and S1 tetramer, respectively. The obtained time‐resolved spectroscopic data provide a clear view of the excited‐state dynamics of the [Pt(CN)4 2− ] oligomers in the femto‐/picosecond time region. Abstract : Femtosecond time‐resolved absorption measurements were carried out for aqueous solutions of K2[Pt(CN)4]. Clear oscillations were observed in the temporal profiles of the transient absorption, reflecting nuclear wave‐packet motions initiated by Pt–Pt bond formations in the excited state of the trimer and tetramer.