Four [Tp*W(μ3-S)3Cu3(μ3-Br)]-based clusters: synthesis, structural characterization and third-order NLO properties

• DOI: 10.1039/c1dt10230c
• Publication Date: 2011-07-06T08:31:21Z
• Authors: Xue Lü; Xi Chen; Zhi-Gang Ren; Jian-Ping Lang; Dong Liu; Zhen-Rong Sun
• Keywords: Characterization

Treatment of [Et4N][Tp*W(μ3-S)3(CuBr)3] (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate) (1) with an excess α-methylpyridine (α-MePy) and NH4PF6 in CH2Cl2 afforded a cationic cluster [Tp*W(μ3-S)3Cu3(α-MePy)3(μ3-Br)](PF6) (2) while the reaction 1 1,4-pyrazine (1,4-pyz) MeCN–CH2Cl2 at 65 °C produced polymeric [Tp*W(μ3-S)3Cu3(1,4-pyz)((1,4-pyz)0.5)2(μ3-Br)][Tp*W(μ3-S)3(CuBr)3] (3). Reactions melamine (MA) : or 2 gave rise to another [{Tp*W(μ3-S)3Cu3Br(μ3-Br)}2(MA)2] (4) neutral [Tp*W(μ3-S)3Cu3Br(μ3-Br)(MA)2] (5), respectively. Compounds 2–5 were characterized by elemental analysis, IR spectra, UV-vis 1H NMR, electrospray ionization (ESI) mass spectra X-ray crystallography. The cation has cubane-like [Tp*W(μ3-S)3Cu3(μ3-Br)] structure each α-MePy ligand coordinated one Cu(I) center. For 3, core is interconnected 1,4-pyz bridges form 1D zigzag chain [Tp*W(μ3-S)3(CuBr)3]− anions arranged along its two sides. 4, interlinked MA afford spiral chain. 5 adopts which terminal Br ligands are three Cu centers. third-order nonlinear optical (NLO) properties 1–5 DMF investigated femtosecond degenerate four-wave mixing (DFWM) technique 80 fs pulse width 800 nm. exhibit good NLO responses, 3 4 possess largest second-order hyperpolarizability γ values among known W/Cu/S clusters bearing [Tp*WS3] unit.