Diverse Tp~*-capped W-Cu-S Clusters From One-pot Assembly Involving In Situ Thiolation Of Phosphines

In the last three decades, the chemistry of Mo（W）-M’-S（M’ = Fe, Cu, Ag, Au, etc.） clusters has advanced significantly. This type of clusters usually exhibits third-order nonlinear-optical（NLO） properties, and can also be applied in several other fields, such as catalysis, adsorption and sensing. In the recent few years, a key effort in our group is to synthesize Tp^*（Tp）-W（Mo）-Cu（Ag）-S clusters for the above mentioned applications. The reactions among W（Mo） precursor and Cu（I） salts in the presence of bridging/chelating ligands gave rise to a series of cluster superstructures with intriguing NLO properties. To further advance this field, we tried out the in situ ligand formation reaction toward a new class of Tp^*-W-Cu-S clusters in this thesis.A one-pot assembly of [Et₄N][Tp^*WS₃]（Tp^* =hydridotris（3,5-dimethylpyrazol-1-yl）borate）（1）, [Cu（MeCN）₄]PF₆ and bis- or tetra-phosphine ligands, such as 1,2-bis-（diphenylphosphino）ethane（dppe）, 1,3-bis（diphenylphosphino）propane（dppp）, 1,4-bis（diphenylphosphino）butane（dppb） and N,N,N′,N′-tetrakis-（diphenylphosphinomethyl）ethylenediamine（dppeda）, gives six Tp^*-W-Cu-S clusters in the absence/presence of S8, namely, [（Tp^*WS₃Cu2Cl）2（dppe）]（2）, [Tp^*WS₃Cu4（dppp）2（μ4-Cl）（μ-Cl）]PF₆?MeCN（3?MeCN）, [（Tp^*WS₃Cu3）2（μ4-Cl）（μ-Cl）2（dpppS2）]（4）, [（Tp^*WS₃Cu2Cl）2（dppbS2）]?2MeCN?2H2O（5?2MeCN?2H2O）, [（Tp^*WS₃Cu3Cl2）2（dppbS2）]（6） and [（Tp^*WS₃Cu3）2（Ph2PS2）3（μ6-Cl）0.5]（PF₆）0.5?0.75CH2Cl2（7?0.75CH2Cl2） respectively. Compounds 2-7 are characterized by elemental analysis, IR, UV-Vis, 1H and 31P{1H} NMR, ESI-MS and single-crystal X-ray diffraction. Besides, we also test the NLO properties of these compounds. The γ value of the compounds are higher than that of the precursor 1.In order to further expand the structural diversity of the Tp^*-W-Cu-S clusters, we further chose a tridentate phosphine ligand bis（2-diphenylphosphinoethyl）phenylphosphine（bpep） to explore its reactivity. Similar to the above method, the reaction of compound 1, [Cu（MeCN）₄]PF₆ and bpep gives rise to a butterfly-shaped compound [Tp^*WS₃Cu2（bpep）]PF₆?Et2O（8?Et2O）. Moreover, from a simple P,N-hybrid ligand diphenyl-2-pyridylphosphine（dppy） and in the presence of S8, a butterfly-shaped compound [Tp^*WS₃Cu2（dppyS）Cl]（9） is also obtained. Compounds 8 and 9 are characterized by IR, UV-Vis, ESI-MS and single-crystal X-ray diffraction. In compound 8, the three P atoms in bpep ligand bond to the two Cu centers in [Tp^*WS₃Cu2]. In compound 9, the dppy ligand react with S8 in situ to give dppyS, further function as a chelating ligand to bind with one Cu center of the butterfly-shaped [Tp^*WS₃Cu2] cluster skeleton.