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• 作者：Belé ; n Gil ; Juan Fornié ; s ; Julio G&oacute ; mez ; Elena Lalinde ; Antonio Martí ; n ; and ; M. Teresa Moreno
• 刊名：Inorganic Chemistry
• 出版年：2006
• 出版时间：September 18, 2006
• 年：2006
• 卷：45
• 期：19
• 页码：7788 - 7798
• 全文大小：489K
• 年卷期：v.45,no.19(September 18, 2006)
• ISSN：1520-510X

文摘

New alkynyl complexes [Pt₂M₄{Cmages/entities/tbd1.gif">C(3-OMe)C₆H₄}₈] (M = Ag 1, Cu 2) have been synthesized and their structuresand properties compared to those of related [Pt₂M₄(Cmages/entities/tbd1.gif">CPh)₈] compounds. For the Pt-Ag derivatives, the X-raystructures of the discrete yellow solvate monomer, [Pt₂Ag₄{Cmages/entities/tbd1.gif">C(3-OMe)C₆H₄}₈]·2THF ([1·2THF]), and the darkgarnet unsolvated polymeric form, [Pt₂Ag₄{Cmages/entities/tbd1.gif">C(3-OMe)C₆H₄}₈]_{mages/entities/infin.gif">} ([1]_{mages/entities/infin.gif">}), are presented. The yellow form ([1·2THF])exhibits a distorted octahedral geometry of the metal centers with the platinum atoms mutually trans and the foursilver atoms in the equatorial plane. Pairs of Ag atoms are weakly bridged by THF molecules [mages/entities/mgr.gif">-Ag₂···O(THF)].The garnet form ([1]_{mages/entities/infin.gif">}) has an unprecedented infinite stacked chain of octahedral clusters linked by short Pt···Ptbonds (3.1458(8) Å). In both forms, different types of weak C-H···O (OMe) hydrogen bonds are observed. Forcomparative purposes, we have also provided the crystal structures of the yellow monomer form, [Pt₂Ag₄-(Cmages/entities/tbd1.gif">CPh)₈]·CHCl₃, and the red dimer form, [Pt₂Ag₄(Cmages/entities/tbd1.gif">CPh)₈]₂ (Pt-Pt 3.221(2) Å). These clusters display intensephotoluminescence in both solution and the solid state, at room temperature and 77 K. The emission observed forthe yellow form [1·2THF] in the solid state is assigned to a ³MLM'CT [Pt(d)/mages/gifchars/pi.gif" BORDER=0 >(Cmages/entities/tbd1.gif">CR) mages/entities/rarr.gif"> Pt(p_z)/Ag(sp)/mages/gifchars/pi.gif" BORDER=0 >*(Cmages/entities/tbd1.gif">CR)]state modified by Pt···Ag, Ag...Ag, and Ag···(THF) contacts. However, in the garnet form [1]_{mages/entities/infin.gif">} and in 2, the emissionsare related to the axial Pt-Pt bonds and are assigned as phosphorescence from a metal-metal-to-ligand charge-transfer (³MMLCT) excited state ([1]_{mages/entities/infin.gif">}), or an admixture of a metal-metal (Pt-Pt) centered ³(dmages/gifchars/sigma.gif" BORDER=0 >*p_zmages/gifchars/sigma.gif" BORDER=0 >) and ³MMLCTexcited state (2). For 1, a remarkable quenching and a shift to higher energies in the emission is observed onchanging from CH₂Cl₂ to THF, and for both 1 and 2, the emission spectra at 77 K varies with the concentration,showing their tendency to stack even in glass.