The presence of electron deficient unit in 1a to the molecular core significantly reduces the LUMO levels and energy gap.
Small molecules, SM1 and SM2, with bithiophene-imide as the central electron deficient unit and bridged thiophene and terminal triphenyl amine as electron rich units, have been designed and synthesized.
Hydroxyapatite has a large and complex unit cell, and therefore the interaction between such unit and a tiny acid calls for a special array in which the aspartic acid is enclosed inside a carbonated, calcium deficient unit, apparently without changing its external appearance and is able to start assemblage of regular apatite units.
They are usually regular copolymers with alternating electron deficient and electron rich units along the polymer backbone, that exhibit a relatively low band gap associated with an intramolecular charge transfer transition between the electron rich and electron deficient units.
This may be in part because typical electron deficient units like benzothiadiazole have no positions available for alkyl chains and therefore solubilizing groups must be located on the periphery of the molecule, making the LUMO less sterically accessible for electron transfer.
Stalder, R., Mei, J., Graham, K. R., Estrada, L. A. & Reynolds, J. R. Isoindigo, a versatile electron-deficient unit for high-performance organic electronics.
Benzo[1,2-b 4,5-b′]dithiophene-4,8-dione (Benzo[1,2-b 4,5-b′]dithiophene-4,8-dione
A new series of copolymers with carbazole as the electron-rich unit and dihexyl-2H-benzimidazole as the electron-deficient unit are synthesized.
These polymers showed typical characteristics of low-band gap polymers through the internal charge transfer (ICT) between 4H-cyclopenta[def]phenanthrene as the electron-rich unit and di(thien-2-yl -2H-benzimidazole-2′-spirocyclohexane thien-2-yl -2H-benzimidazole-2′-spirocyclohexane
In this study, we designed and synthesized two PDI-based n-type polymers named as PF-PDI and PBDT-PDI, in which PDI was used as electron-deficient unit and fluorene (F) or benzodithiophene (BDT) were used as electronrich components.
9H-Carbazole as electron-rich unit and di-2-thienyl-2,1,3-benzothiadiazole di-2-thienyl-2,1,3-benzothiadiazole di-2-thienyl-2,1,3-benzothiadiazole di-2-thienyl-2,1,3-benzothiadiazole di-2-thienyl-2,1,3-benzothiadiazolemers with DTBTerent ratior of tetrafluorophenylene unit (PCDTBTF-1, PCDTBTF-3 asd PCDTBTF-10).
