STERICALLY HINDERED PI-BRIDGE NONLINEAR OPTICAL CHROMOPHORES, PROCESSES INCLUDING SAME, AND DEVICES THEREFROM
In various embodiments, chromophores are described that include novel electron acceptors, novel electron donors, and/or novel conjugated bridges that are useful in nonlinear optical applications. In some embodiments, the present invention provides chromophore architectures wherein a chromophore contains more than one electron acceptor in electronic communication with a single electron donor, and/or more than one electron donor in electronic communication with a single electron acceptor. Also described is processes for providing materials comprising the novel chromophores and polymer matrices containing the novel chromophores. Electro-optic devices described herein contain one or more of the described electron acceptors, electron donors, conjugated bridges, or chromophores.
1 . A chromophore comprising a ring locked bithiophene π bridge having the formula
wherein, independently at each occurrence:
π 1 is absent or a bridge that provides electronic conjugation between D and the remainder of the molecule;
π 2 is absent or a bridge that provides electronic conjugation between A and the remainder of the molecule;
D is an electron donating group having low electron affinity relative to the electron affinity of A;
A is an electron accepting group having high electron affinity relative to the electron affinity of D;
X is O, S, Se or CR 2 ;
R is hydrogen, halogen, alkyl, aryl, or heteroalkyl;
n=1-4;
and any one of π 1 , π2 , D, or A can be further independently substituted with one or more halogen, alkyl, aryl, or heteroalkyl.
2 . The chromophore of claim 1 , wherein D is selected from the group consisting of
wherein, independently at each occurrence:
R 1 is alkyl, aryl or heteroalkyl;
R 2 is hydrogen, alkyl, aryl or heteroalkyl;
Y is O, S or Se;
m is 2, 3 or 4;
p is 0, 1 or 2; and
q is 0 or 1.
3 . The chromophore of claim 2 , wherein D is selected from the group consisting of
4 . The chromophore of claim 1 , wherein A is selected from the group consisting of
wherein, independently at each occurrence:
R 1 is alkyl, aryl or heteroalkyl;
R 2 is hydrogen, alkyl, aryl or heteroalkyl;
Y is O, S or Se; and
q is 0 or 1.
5 . The chromophore of claim 4 , wherein A has the formula
6 . There chromophore of claim 1 wherein π 1 and π 2 each independently comprise
wherein, independently at each occurrence:
Z 1 is O, S, Se, NR 1 , C(R 1 ) 2 or —C(R 1 )═C(R 1 )—;
p is 0, 1 or 2;
o is 0, 1 or 2;
o+p is at least 1;
R 2 is hydrogen, alkyl, aryl or heteroalkyl;
Z 2 has the formula
q is 0 or 1.
7 . The chromophore of claim 6 , wherein π 1 and π 2 each independently comprise an alkene or a thiophene.
8 . The chromophore of claim 7 , wherein the thiophene has the formula
wherein X is O or S and R 1 is alkyl, aryl or heteroalkyl.
9 . An electro-optic device comprising the chromophore of claim 1 .
10 . An electro-optic device comprising the chromophore of claim 2 .
11 . An electro-optic device comprising the chromophore of claim 4 .
12 . An electro-optic device comprising the chromophore of claim 6.