Half-lantern cyclometalated Pt(ii) and Pt(iii) complexes with bridging heterocyclic thiolate ligands: synthesis, structural characterization, and electrochemical and photophysical properties12. (7th May 2019)

• Record Type: Journal Article
• Authors: Shahsavari, Hamid R.; Lalinde, Elena; Moreno, M. Teresa; Niazi, Maryam; Kazemi, Sayed Habib; Abedanzadeh, Sedigheh; Barazandeh, Mohammad; Halvagar, Mohammad Reza
• Is Part Of: New journal of chemistry. Volume 43:Number 20(2019)
• Page Start: 7716
• Page End: 7724
• Publication Date: 2019-05-07
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c9nj00969h
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Half-lantern Pt(ii ) and Pt(iii ) cyclometalated binuclear complexes, bridged with various heterocyclic thiolate ligands, were synthesized and studied by electrochemical and photophysical techniques. Abstract : The half-lantern Pt(ii )–Pt(ii ) cyclometalated complexes [{Pt(ppy-κ 2 C, N)(μ-N^S)}2 ] [Hppy = 2-phenylpyridine; HN^S = 2-mercaptopyridine (Spy, 1a ), 5-(trifluoromethyl)-2-mercaptopyridine (SpyCF3, 1b ), 2-mercaptopyrimidine (SpyN, 1c ), 2-mercaptobenzothiazole (SBt, 1d ) and 2-mercaptobenzimidazole (SBi, 1e )] were synthesized by reaction of [Pt(ppy-κ 2 C, N)Cl(dmso)] (A ) with an ethanolic solution of the corresponding sodium thiolate salts, thus providing a new direct approach to obtain this type of complexes in high yield.1a, 1d and1e were previously reported by other routes (see the text). These complexes exhibit intense red emission (QY 13.2–37.4%, CH2 Cl2 ) derived from a triplet metal–metal to ligand charge transfer ( 3 MMLCT) excited state both in CH2 Cl2 solution and in the solid state (298 and 77 K), consistent with strong Pt⋯Pt interactions. The electrochemical behavior of these complexes was examined to get insight into the influence of the bridging ligand on the metallointeractions. By stirring compounds1a–c in CHCl3, two electron oxidized diplatinum(iii ) derivatives [{Pt(ppy-κ 2 C, N)(μ-N^S)Cl}2 ] (2a–c ) were successfully obtained (2a previously reported by Kato et al. ). The X-ray structure of2c ·CHCl3 confirmed the retention of the half-lantern structure for the Pt(iii )–Pt(iii ) dichloro complex and a shortening of the Pt–Pt distance in relation to1 .