Browsing by Author "Ozcan, Emrah"

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External complexation of BODIPYs by CB[7] improves in-cell fluorescence imaging
(ROYAL SOC CHEMISTRYTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND, 2021) Ayhan, Mehmet Menaf; Ozcan, Emrah; Alkan, Fahri; Cetin, Metin; Un, Ilker; Bardelang, David; Cosut, Bonyemin; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Alkan, Fahri
Organic luminescent compounds with high emission properties play a crucial role in fluorescence labelling and optoelectronic devices. In this work, we prepared three water soluble BODIPY derivatives (B-4, B-5, and B-6) which are weakly fluorescent due to non-radiative relaxation pathways (charge transfer: CT or heavy atom effect). However, CB[7] significantly improves BODIPY fluorescence by similar to 10 fold for B-4, and by similar to 3 fold for B-5. The (TD)DFT analyses suggest that for B-4 and B-5, the CT state is blue-shifted as a result of the external binding of CB[7] near the pyridinium groups. This effect favoured a radiative decay through a locally-excited (LE) pi ->pi* transition state of BODIPYs resulting in a CB[7]-induced emission increase in solution (and in the solid state), without compromising singlet-to-triplet intersystem crossing (ISC). The improved emission of the BODIPY center dot CB[7] complexes was used for the fluorescence imaging of U87 cells illustrating the relevance of this approach. These results suggest that BODIPY center dot CB[7] complexes could be used as theragnostic agents by combining fluorescence imaging and treatment by photodynamic therapy.
A Solution-Processable meso-Phenyl-BODIPY-Based n-Channel Semiconductor with Enhanced Fluorescence Emission
(WILEY-V C H VERLAG GMBH, POSTFACH 101161, 69451 WEINHEIM, GERMANY, 2019) Ozcan, Emrah; Ozdemir, Mehmet; Ho, Dongil; Zorlu, Yunus; Ozdemir, Resul; Kim, Choongik; Usta, Hakan; Cosut, Bunyemin; 0000-0002-0618-1979; 0000-0002-7957-110X; 0000-0001-6530-0205; 0000-0001-6325-5674; 0000-0003-2811-1872; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
The cover feature shows the delicate balance between locally excited (LE) and twisted intramolecular charge-transfer (TICT) states, which could be controlled by solvent polarity and nano-aggregation, of a meso-phenyl-BODIPY-based fluorescent semiconductor. The dihedral angle between the meso-aromatic unit and BODIPY pi-core was found to be the key factor in this balance. This is the first report of highly emissive characteristics for an A-D-A type BODIPY-based n-channel semiconductor. Details are given in the Full Paper by B. Cosut, H. Usta, C. Kim, and co-workers (DOI: 10.1002/cplu.201900317).