Solution-processable indenofluorenes and methods to generate solution-processable indenofluorenes

A method of forming a donor-acceptor small molecule or a donor-acceptor copolymer, comprising:

• forming an indenofluorene, the indenofluorene having the formula
• wherein:
• each of R1 and R1′ is independently a C1 to C50 alkyl radical, a C1 to C50 substituted alkyl radical, a C1 to C50 alkoxy radical, a C1 to C50 substituted alkoxy radical, a C4 to C20 unsubstituted aryl ring, a C4 to C20 substituted aryl ring, a C4 to C20 unsubstituted heteroaryl ring, or a C4 to C20 substituted heteroaryl ring;
• Ar is a C4 to C20 unsubstituted aryl radical, a C4 to C20 substituted aryl radical, a C4 to C20 unsubstituted heteroaryl radical, or a C4 to C20 substituted heteroaryl radical;
• and
• Alkyl is a C1 to C50 alkyl radical or a C1 to C50 substituted alkyl radical, the C1 to C50 alkyl radical and the C1 to C50 substituted alkyl radical being linear, branched, or cyclic, and when cyclic, the C1 to C50 alkyl radical and the C1 to C50 substituted alkyl radical being non-aromatic;
• forming an electron donor;
• and
• reacting the indenofluorene with the electron donor in a cross-coupling reaction, wherein the cross-coupling reaction is a Suzuki cross-coupling reaction, a Suzuki cross-coupling polymerization reaction, a Stille cross-coupling reaction, or a Stille cross-coupling polymerization reaction.

A method of forming a donor-acceptor small molecule or a donor-acceptor copolymer, comprising:

• forming an indenofluorene, the indenofluorene having the formula
• wherein:
• each of R1 and R1′ is independently a C1 to C50 alkyl radical, a C1 to C50 substituted alkyl radical, a C1 to C50 alkoxy radical, a C1 to C50 substituted alkoxy radical, a C4 to C20 unsubstituted aryl ring, a C4 to C20 substituted aryl ring, a C4 to C20 unsubstituted heteroaryl ring, or a C4 to C20 substituted heteroaryl ring;
• Ar is a C4 to C20 unsubstituted aryl radical, a C4 to C20 substituted aryl radical, a C4 to C20 unsubstituted heteroaryl radical, or a C4 to C20 substituted heteroaryl radical;
• Alkyl is a C1 to C50 alkyl radical or a C1 to C50 substituted alkyl radical, the C1 to C50 alkyl radical and the C1 to C50 substituted alkyl radical being linear, branched, or cyclic, and when cyclic, the C1 to C50 alkyl radical and the C1 to C50 substituted alkyl radical being non-aromatic;
• and
• when the indenofluorene includes Alkyl′, the Alkyl′ is a C1 to C50 alkyl radical or a C1 to C50 substituted alkyl radical, the C1 to C50 alkyl radical and the C1 to C50 substituted alkyl radical being linear, branched, or cyclic, and when cyclic, the C1 to C50 alkyl radical and the C1 to C50 substituted alkyl radical being non-aromatic;
• and
• reacting the indenofluorene with an electron donor in a cross-coupling reaction, wherein the cross-coupling reaction is a Suzuki cross-coupling reaction, a Suzuki cross-coupling polymerization reaction, a Stille cross-coupling reaction, or a Stille cross-coupling polymerization reaction, wherein the electron donor comprises a thiophene.