title: Locked ortho- and para-core chromophores of green fluorescent protein; dramatic emission enhancement via structural constraint.
abstract: We report the design strategy and synthesis of a structurally locked GFP core chromophore p-LHBDI, its ortho-derivative, o-LHBDI, and H2BDI possessing both para- and ortho-hydroxyl groups such that the inherent rotational motion of the titled compounds has been partially restricted. o-LHBDI possesses a doubly locked configuration, i.e., the seven-membered ring hydrogen bond and five-membered ring C(4-5-10-13-14) cyclization, from which the excited-state intramolecular proton transfer takes place, rendering a record high tautomer emission yield (0.18 in toluene) and the generation of amplified spontaneous emission. Compared with their unlocked counterparts, a substantial increase in the emission yield is also observed for p-LHBDI and H2BDI in anionic forms in water, and accordingly the structure versus luminescence relationship is fully discussed based on their chemistry and spectroscopy aspect. In solid, o-LHBDI exhibits an H-aggregate-like molecular packing, offers narrow-bandwidth emission, and has been successfully applied to fabricate a yellow organic light emitting diodes (λmax = 568 nm, ηext = 1.9%) with an emission full width at half-maximum as narrow as 70 nm.
authors: Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University , Taipei 10617, Taiwan, R.O.C.
authors: Yen-Hao
authors: YH
authors: Hsu
authors: Yi-An
authors: YA
authors: Chen
authors: Huan-Wei
authors: HW
authors: Tseng
authors: Zhiyun
authors: Z
authors: Zhang
authors: Jiun-Yi
authors: JY
authors: Shen
authors: Wei-Ti
authors: WT
authors: Chuang
authors: Tzu-Chieh
authors: TC
authors: Lin
authors: Chun-Shu
authors: CS
authors: Lee
authors: Wen-Yi
authors: WY
authors: Hung
authors: Bor-Cherng
authors: BC
authors: Hong
authors: Shih-Hung
authors: SH
authors: Liu
authors: Pi-Tai
authors: PT
authors: Chou
mesh_terms: D049452:Green Fluorescent Proteins / Q000737:chemistry*; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D007189:Indans / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D055668:Photochemical Processes; D013237:Stereoisomerism
chemical_list: D007093:Imidazoles; D007189:Indans; D049452:Green Fluorescent Proteins