Synthesis, Structure, and Characterization of Emissive Neutral Dinuclear CuI Complexes with a Tetraphosphane Bridging Ligand. Issue 18 (13th May 2016)

• Record Type: Journal Article
• Authors: Chen, Jin; Teng, Teng; Wang, Jin‐Yun; Kang, Liju; Chen, Xu‐Lin; Xu, Liang‐Jin; Yu, Rongmin; Lu, Can‐Zhong
• Is Part Of: European journal of inorganic chemistry. Issue 18(2016)
• Page Start: 3036
• Page End: 3041
• Publication Date: 2016-05-13
• Subjects: Copper -- N ligands -- P ligands -- Luminescence -- Density functional calculations; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201600030
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : A series of new dinuclear copper complexes with a tetraphosphane bridging ligand, [{(pz4 B)Cu}2 (µ‐tpbz)] (1 ), [{(pz2 BH2 )Cu}2 (µ‐tpbz)] (2 ), and [{(tz2 BH2 )Cu}2 (µ‐tpbz)] (3 ) [tpbz = 1, 2, 4, 5‐tetrakis(diphenylphosphanyl)benzene, pz4 B = tetrakis(pyrazol‐1‐yl)borate, pz2 BH2 = bis(pyrazol‐1‐yl)borohydrate, and tz2 BH2 = bis(1, 2, 4‐triazol‐1‐yl)borohydrate], have been synthesized and structurally characterized. The Cu I atoms in these complexes are four‐coordinate and adopt a tetrahedral coordination geometry. In each complex, the copper centers are bridged by a tpbz ligand and each Cu I is further terminally chelated by a borate diimine anion. The central phenylene ring and the phosphine atoms of the tpbz ligand are essentially planar. The two Cu I atoms in each molecule are located above and below the (P2 C6 H2 P2 ) mean plane, respectively, leading to a chair‐like conformation for the [Cu](P2 C6 H2 P2 )[Cu] fragment. The distances between the Cu I atoms in each complex are about 8.7 Å. In the solid state, these complexes are emissive and exhibit yellow–orange photoluminescence [emission peaks, λ max = 580 nm (1 ), 569 nm (2 ), 540 nm (3 )] with lifetimes of 7.4–20.5 µs and quantum yields Φ = 0.07–0.45 at room temperature. Theoretical and experimental results indicate that these complexes have the lowest singlet (S1 ) state and the lowest triplet (T1 ) state with very close energy levels, and display thermally activated delayed fluorescence (TADF) at ambient temperature. Abstract : Three neutral dinuclear Cu I complexes with a tetraphosphane bridging ligand have been synthesized. The emissive properties at 298 and 77 K as well as theoretical studies point to thermally activated delayed fluorescence (TADF).