Structural Variability in Ag(I) and Cu(I) Coordination Polymers with Thioether-Functionalized Bis(pyrazolyl)methane Ligands

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• 作者：Irene Bassanetti ; Luciano Marchi貌
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：November 7, 2011
• 年：2011
• 卷：50
• 期：21
• 页码：10786-10797
• 全文大小：1183K
• 年卷期：v.50,no.21(November 7, 2011)
• ISSN：1520-510X

文摘

We present here two ligand classes based on a bis(pyrazolyl)methane scaffold functionalized with a rigid (-Ph-S-Ph) or flexible (-CH₂-S-Ph) thioether function: L^RPhS (R = H, Me) and L^RCH₂S (R = H, Me, iPr). The X-ray molecular structures of Ag(I) and Cu(I) binary complexes with L^RPhS or L^RCH₂S using different types of counterions (BF₄^{鈥?/sup>, PF₆鈥?/sup>, and CF₃SO₃鈥?/sup>) are reported. In these complexes, the ligands are N₂ bound on a metal center and bridge on a second metal with the thioether group. In contrast, when using triphenylphosphine (PPh₃) as an ancillary ligand, mononuclear ternary complexes [M(L)PPh₃]+ (M = Cu(I), Ag(I); L = LRPhS, LRCH₂S) are formed. In these complexes, the more flexible ligand type, LRCH₂S, is able to provide the N₂S chelation, whereas the more rigid LRPhS ligand class is capable of chelating only N₂ because the thioether function preorganized, as it did in the coordination polymers, to point away from the metal center. Rigid potential-energy surface scans were performed by means of density functional theory (DFT) calculations (B3LYP/6-31+G) on the two representative ligands, LHPhS and LHCH₂S. The surface scans proved that the thioether function is preferably oriented on the opposite side of the bispyrazole N₂ chelate system. These results confirm that both ligand classes are suitable components for the construction of coordination polymers. Nevertheless, the methylene group that acts as a spacer in LHCH₂S imparts an inherent flexibility to this ligand class so that the conformation responsible for the N₂S chelation is energetically accessible.}