Phosphorescent platinum(ii) alkynyls end-capped with benzothiazole units. Issue 14 (22nd March 2017)

• Record Type: Journal Article
• Authors: Lara, Rebeca; Lalinde, Elena; Moreno, M. Teresa
• Is Part Of: Dalton transactions. Volume 46:Issue 14(2017)
• Page Start: 4628
• Page End: 4641
• Publication Date: 2017-03-22
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c7dt00029d
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Phosphorescent platinum(ii ) alkynyls . Phosphorescent trans -bis(alkynyl) bis(phosphine) or bis(cyanide) Pt II derivatives (1–4 ) based on the 2-phenylbenzothiazole unit have been prepared. The negative solvatochromic behavior of4 has been analyzed by the Kamlet–Taft solvent scale and the Gutmann's acceptor numbers. The optical properties were addressed by TD and DFT calculations on2 and4 . Abstract : Symmetric trans -bis(alkynyl)bis(phosphine) Pt II complexes based on the 2-phenylbenzothiazole (pbt) unit [ trans -Pt(CC-pbt)2 L2 ] [L = PPh3 1, PEt3 2, 1, 3, 5-triaza-7-phosphaadamantane (PTA)3 ] and the mixed alkynyl–cyanide anionic complex (NBu4 )2 [ trans -Pt(CC-pbt)2 (CN)2 ] (4 ) were synthesized. The complexes have been fully characterized including X-ray crystallography for2 and4 . All complexes display long-lived emission with moderate quantum yields ( ϕ 6.8–22.6%) in doped PMMA films at 298 K and complex4 is also emissive in DMSO fluid and in rigid media (solid, glass at 77 K). Complex4 displays a negative solvatochromic behavior. Absorption and emission energies have been analyzed by means of linear solvation energy based on Kamlet–Taft solvatochromism parameters and the Gutmann's acceptor numbers. The study indicates that solvatochromism is due to the contribution of solvent-to-cyanide hydrogen bonding and increased solvent dipolarity–polarizability. TD and TD-DFT calculations were performed on the ground and excited states of two different conformers of2 and4 to provide insight into the structural, electronic and optical properties of these systems.