Narrow band gap conjugated polymers employing cross-conjugated donors useful in electronic devices
The invention provides for new polymer compounds and methods for the preparation of modular narrow band gap conjugated compounds and polymers that incorporate exocyclic cross-conjugated donors or substituents, as well as novel monomer components of such polymers and the resulting products which comprise materials and useful electronic devices with novel functionality.
1. A method of synthesizing a narrow band gap conjugated polymer, comprising steps of:
copolymerizing at least one first monomer or oligomer having the formula:
wherein G is a leaving group suitable for a cross-coupling polymerization reaction,
FG is selected from the group consisting of substituted C 1 -C 36 hydrocarbyl, unsubstituted C 6 -C 20 aryl, substituted C 6 -C 20 aryl, unsubstituted C 3 -C 20 heteroaryl, substituted C 3 -C 20 heteroaryl, unsubstituted C 0 -C 36 hydrocarbylene C 6 -C 20 aryl-C 0 -C 36 hydrocarbyl, substituted C 0 -C 36 hydrocarbylene, C 6 -C 20 aryl, C 0 -C 36 hydrocarbyl, F, Cl, Br, I, CN, —R 2 , SR 2 —OH, —OR 2 , —COOH, —COOR 2 , —NH 2 , —NHR 2 , or NR 2 R 3 , where R 2 and R 3 are independently selected from a C 1 -C 24 hydrocarbyl group;
m is an integer of at least 1;
Y is selected from the group consisting of S, BR 3 , PR 3 , Se, Te, NH, or Si, wherein R 3 is a C 1 -C 24 hydrocarbyl group; and
FG′ is selected from the group consisting of unsubstituted C 6 -C 20 aryl, substituted C 6 -C 20 aryl, unsubstituted C 3 -C 20 heteroaryl and substituted C 3 -C 20 heteroaryl;
a second monomer selected from the group consisting of monomers that provide the following structural units in the copolymer:
and
optionally a third monomer comprising double or triple bonds separated by a single bond;
thereby forming a reaction mixture;
adding a catalyst to the reaction mixture;
heating the reaction mixture and catalyst; cooling, purifying, washing, and drying the reaction mixture to form the narrow band gap conjugated polymer having a band gap of 0.1 to 1.2 eV.
2. The method of claim 1 , wherein the first monomer is an exocyclic olefin substituted cyclopentadithiophene donor.
3. The method of claim 1 , wherein the polymers synthesized have the formula:
where FG is selected from the group consisting of substituted C 1 -C 36 hydrocarbyl, unsubstituted C 6 -C 20 aryl, substituted C 6 -C 20 aryl, unsubstituted C 3 -C 20 heteroaryl, substituted C 3 -C 20 heteroaryl, unsubstituted C 0 -C 36 hydrocarbylene C 6 -C 20 aryl-C 0 -C 36 hydrocarbyl, substituted C 0 -C 36 hydrocarbylene, C 6 -C 20 aryl, C 0 -C 36 hydrocarbyl, F, Cl, Br, I, CN, —R 2 , SR 2 —OH, —OR 2 , —COOH, —COOR 2 , —NH 2 , —NHR 2 , or NR 2 R 3 , where R 2 and R 3 are independently selected from a C 1 -C 24 hydrocarbyl group;
FG′ is selected from the group consisting of unsubstituted C 6 -C 20 aryl, substituted C 6 -C 20 aryl, unsubstituted C 3 -C 20 heteroaryl and substituted C 3 -C 20 heteroaryl;
τ A is selected from the following structural units:
and units P4-P8 shown below:
τ S represents a conjugated spacer comprising double or triple bonds in a molecule separated by a single bond, across which some sharing of electrons occurs;
m is an integer of at least 1;
Y is selected from the group consisting of S, BR 3 , PR 3 , Se, Te, NH or Si, wherein R 3 is a C 1 -C 24 hydrocarbyl group, and
n is an integer>1.
4. The method of claim 1 , wherein the first monomer comprises at least one monomer or oligomer having the formula:
where G is a leaving group suitable for a cross-coupling polymerization reaction,
FG is C 0 hydrocarbyl;
FG′ is selected from the group consisting of substituted C 6 -C 20 aryl and substituted C 3 -C 20 heteroaryl; and
Y is selected from the group consisting of S, BR 3 , PR 3 , Se, Te, NH or Si, wherein R 3 is a C 1 -C 24 hydrocarbyl group.
5. The method of claim 4 , wherein G is selected from the group consisting of Br, Cl, I, triflate (trifluoromethanesulfonate), a trialkyl tin compound, boronic acid (—B(OH) 2 ), or a boronate ester (—B(OR 5 ) 2 , where each R 5 is C 1 -C 12 alkyl or the two R 5 groups combine to form a cyclic boronic ester.
6. The method of claim 4 , wherein G is selected from the group consisting of Br, H, or any group suitable for direct heteroarylation polycondensation.
7. The method of claim 1 , wherein the synthesis of the polymers comprises copolymerization of two or more monomers.
8. The method of claim 1 , wherein the synthesized polymers have a band gap of between 0.7 eV to 1.2 eV.
9. The method of claim 1 , further comprising a step of incorporating the polymers into organic optoelectronic devices.
10. The method of claim 1 , further comprising a step of incorporating the polymers into hybrid organic-inorganic optoelectronic devices.