Efficient synthesis of rigid ladder polymers

A polymer represented by one of the following formulas:

• wherein R1, R2, R3, and R4 are independently selected from hydride group, alkyl groups, aryl groups, heterocyclic groups, halogen groups, groups including a —O— moiety, groups including a —O(CO)— moiety, groups including a —O(CO)O— moiety, groups including a —O(CO)N< moiety), groups including a —S— moiety, groups including a —B< moiety, —NO2, groups including a —N< moiety, groups including a —P< moiety, groups including a —(PO)< moiety, —CHO, groups including a —(CO)— moiety, groups including a —(CO)O— moiety, groups including a —(CO)N< moiety, and groups including a —Si≡ moiety;
• wherein X1 and X2 are independently selected from —[O]—, —[S]—, —[B(O)Ra]—, —[NRa]—, —[P(O)Ra]—, —[(PO)(O)Ra]—, —[CO]—, —[CRaRb]—, —[C(O)Ra(O)Rb]—, and —[Si(O)Ra(O)Rb]—, and Ra and Rb are independently selected from hydride group, alkyl groups, aryl groups, and heterocyclic groups;
• wherein M and M′ are independently selected from aromatic groups and heterocyclic groups;
• and
• wherein n is an integer that is greater than 1.

A synthesis method comprising:

• reacting at least one monomer A with at least one monomer B, in the presence of a palladium-containing catalyst, a ligand, and a base in an organic solvent,
• wherein the monomer A is selected from (a) aromatic hydrocarbons that are substituted with at least two X groups per molecule and (b) heterocyclic compounds that are substituted with at least two X groups per molecule, and X is a halogen group or a sulfonate group;
• and
• wherein the monomer B is selected from polycyclic compounds including at least two carbon-carbon double bonds per molecule and at least one bridging moiety per molecule.