Synthesis, Characterization, and Bromine Substitution by 4,4'-Di(5-nonyl)-2,2'-bipyridine in CuII(4,4'-di(5-nonyl)-2,2'-bipyridine)Br2

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• 作者：Tomislav Pintauer ; Jian Qiu ; Guido Kickelbick ; and Krzysztof Matyjaszewski
• 刊名：Inorganic Chemistry
• 出版年：2001
• 出版时间：June 4, 2001
• 年：2001
• 卷：40
• 期：12
• 页码：2818 - 2824
• 全文大小：119K
• 年卷期：v.40,no.12(June 4, 2001)
• ISSN：1520-510X

文摘

The crystal structure of a novel compound Cu^II(dNbpy)Br₂ (dNbpy = 4,4'-di(5-nonyl)-2,2'-bipyridine), which isused in the reverse atom transfer radical polymerization, is reported. Cu^II(dNbpy)Br₂ crystallizes in the triclinicP1 space group with a = 12.5283(11) Å, b = 15.0256(14) Å, c = 17.7900(16) Å, ges/gifchars/alpha.gif" BORDER=0> = 90.350(2)ges/entities/deg.gif">, ges/gifchars/beta2.gif" BORDER=0 ALIGN="middle"> = 99.360(2)ges/entities/deg.gif">,ges/gifchars/gamma.gif" BORDER=0 > = 107.937(2)ges/entities/deg.gif">, and Z = 2. The Cu^II center in the complex has a distorted square planar geometry and iscoordinated by two nitrogen atoms of a single dNbpy ligand (Cu-N = 2.011(7) and 2.022(7) Å) and two bromineatoms (Cu-Br = 2.3621(14) and 2.3567(13) Å). The similarity of the absorption spectra in the solid state and insolution suggested that the geometry of the complex remained unchanged upon dissolution. In the presence ofdNbpy, Cu^II(dNbpy)Br₂ undergoes Br substitution to form ionic [Cu^II(dNbpy)₂Br]⁺[Br]^-. ges/gifchars/Delta.gif" BORDER=0 >Hges/entities/deg.gif"> and ges/gifchars/Delta.gif" BORDER=0 >Sges/entities/deg.gif"> valuesfor this equilibrium were negative and dependent on the polarity of the medium. It was found that, under thetypical polymerization conditions (T ges/entities/ge.gif">90 ges/entities/deg.gif">C and the total copper concentration in the range 1.0 × 10^-2-1.0 ×10^-1 M), Cu^IIBr₂ and 2 equiv of dNbpy will predominantly form the neutral Cu^II(dNbpy)Br₂ complex. In a polarmedium under the same conditions, [Cu^II(dNbpy)₂Br]⁺[Br]^- is preferred.