Research, news, Jul. 19th, 2013.
3-D Brickwall Polymeric Structure of TMEDA-Supported 1,4-Dilithio-1,3-Butadiene
Shaoguang Zhang, Ming Zhan, Wen-Xiong Zhang,* and Zhenfeng Xi*
Organometallics 2013, 32, 4020-4023.
The synthesis and X-ray crystallographic structure of a 3-D brickwall coordination polymer of TMEDA-supported dimeric 2,3-dialkyl-1,4-dilithio-1,3-butadiene are reported. TMEDAs behave as bridging coordinating ligands rather than intramolecular chelating ligands. The Li4-tetrahedron core was stable toward the deaggregation of TMEDA because of the small steric hindrance on the butadiene skeleton.
The study on structures of organolithium compounds is of fundamental interest because they are very important in both organometallic chemistry and synthetic chemistry. We have been working on the structures and reaction chemistry of 1,4-dilithio-1,3-butadienes since 1998. The substitution pattern on the butadienyl skeleton remarkably affects the structure of these dilithio compounds. In 2010, we reported the X-ray crystallographic structures of a trimeric all-alkyl-substituted 1,4-dilithio-1,3-butadiene with a Li6 pseudooctahedron and dimeric Me3Si-substituted 1,4-dilithio-1,3-butadienes with Li4 tetrahedra.
The structural information and the ligand effect disclosed in this work are believed to have fundamental significance in organolithium chemistry and related organometallic chemistry.