Beschreibung:
<jats:title>Abstract</jats:title><jats:p>The solution structure and the aggregation behavior of (<jats:italic>E</jats:italic>)‐2‐lithio‐1‐(2‐lithiophenyl)‐1‐phenylpent‐1‐ene (<jats:bold>1</jats:bold>) and (<jats:italic>Z</jats:italic>)‐2‐lithio‐1‐(2‐lithiophenyl)ethene (<jats:bold>2</jats:bold>) were investigated by one‐ and two‐dimensional <jats:sup>1</jats:sup>H‐, <jats:sup>13</jats:sup>C‐, and <jats:sup>6</jats:sup>Li‐NMR spectroscopy. In Et<jats:sub>2</jats:sub>O, both systems form dimers which show homonuclear scalar <jats:sup>6</jats:sup>Li,<jats:sup>6</jats:sup>Li spin‐spin coupling. In the case of <jats:bold>2</jats:bold>, extensive <jats:sup>6</jats:sup>Li,<jats:sup>1</jats:sup>H coupling is observed. In tetrahdrofuran and in the presence of 2 mol of <jats:italic>N</jats:italic>,<jats:italic>N</jats:italic>,<jats:italic>N′</jats:italic>,<jats:italic>N′</jats:italic>‐tetramethylethylylenediamine (tmeda), the dimeric structure of <jats:bold>1</jats:bold> coexists with a monomer. The activation parameters for <jats:italic>intra</jats:italic>‐aggregate exchange in the dimers of <jats:bold>1</jats:bold> and <jats:bold>2</jats:bold> (<jats:bold>1</jats:bold> (Et<jats:sub>2</jats:sub>O): Δ<jats:italic>H</jats:italic>≠ = 62.6 ± 13.9 kJ/mol, Δ<jats:italic>S</jats:italic>≠ = 5.8 ± 14.0 J/mol K, Δ<jats:italic>G</jats:italic>≠(263) = 61.1 kJ/mol; <jats:bold>2</jats:bold> (dimethoxyethane): Δ<jats:italic>H</jats:italic>≠ = 36.9 ± 6.5 kJ/mol, Δ<jats:italic>S</jats:italic>≠ = −61 ± 25 J/mol K, Δ<jats:italic>G</jats:italic>≠(263) = 54.0 kJ/mol) and the thermodynamic parameters for the dimer‐monomer equilibrium for <jats:bold>1</jats:bold> (Δ<jats:italic>H</jats:italic>°; = 26.7 ± 5.5 kJ/mol, Δ<jats:italic>S</jats:italic>° = 63 ± 27 J/mol K), where the monomer is favored at low temperature, were determined by dynamic NMR studies.</jats:p>