Self-assembling behavior of butadienyllithium headgroups in benzene via SANS measurements

The self-assembling behavior of butadienyllithium (-CH2-CH=CH-CH2-Li) headg roups in benzene has been studied via the use of small-angle neutron scatte ring (SANS). The carrier polystyrene chain molecular mass was 2.6K. Previou s work has shown that the styryllithium headgroup can simultaneously form a ggregated architectures encompassing tetramers and dimers along with a smal l number, similar to 0.1%, of chains engaged in the formation of large scal e mass fractal aggregates. That aggregation behavior contradicts the long e ntrenched belief that the sole self-assembled state of styryllithium headgr oups is dimeric. This study shows that the butadienyllithium active centers exhibit more complicated aggregation tendencies than their styryllithium c ounterparts. For example, the butadienyllithium headgroup can form star-sha ped structures with mean functionalities as large as 10 in addition to dime rs. This structural versatility is in obvious conflict with the current pro pagation model that requires tetramers as the solitary aggregation state.