abstract
Two novel triads connecting a BODIPY to ethylenediamine substituted porphyrins via triazine linker have been synthesized and characterized. One of the triads is a linear D-A structure with one BODIPY (D) and one porphyrin (A) bridged by the triazine linker and the other one is a branched A-D 4 structure with the porphyrin core linked to four BODIPY units. The triads show extended absorption in the visible region with contributions from both porphyrin (Soret band centred at 410-430 nm) and BODIPY units (strong absorption at N 502 nm) in good agreement with the expected molar ratio. Both triads exhibit linear and nonlinear optical properties featuring an efficient energy transfer from the BODIPY donor to the porphyrin acceptor. The nonlinear upconverted emission properties of the triads were studied by two-photon excitation in the Near-infrared (NIR, 710-930 nm). The maximum two-photon absorption cross-section values for the triads (40-70 GM) are larger than those typically reported in this wavelength range for porphyrins and BODIPY. Both the green emission of BODIPY (approximate to 514 nm) and the red emission of porphyrins (650-750 nm) were observed under NIR excitation at 930 nm. The distinct features of triads, namely i) an extended absorption; ii) an efficient energy transfer and iii) the nonlinear upconverted emission featuring a large separation between the excitation and emission wavelengths could be beneficial for application in sensing and imaging procedures.
keywords
SENSITIZED SOLAR-CELLS; PHOTOPHYSICAL PROPERTIES; 2-PHOTON ABSORPTION; FLUORESCENT; MOLECULES; DYE; METALLOPORPHYRINS; 1,3,5-TRIAZINE; DERIVATIVES; HYBRIDS
subject category
Chemistry, Applied; Engineering, Chemical; Materials Science, Textiles
authors
Souza, MC; Santos, CIM; Mariz, I; Marques, BS; Machado, LA; Pedrosa, LF; Cavaleiro, JAS; Neves, MGPMS; Mendes, RF; Paz, FAA; Martinho, JMG; Macoas, E
our authors
acknowledgements
Authors are grateful to University of Aveiro, Instituto Superior Tecnico (IST, Portugal) and FCT/MCTES (Fundacao para a Ciencia e Tecnologia/Ministerio da Ciencia e Tecnologia, Portugal) for funding, the research units: QOPNA (FCT UID/QUI/00062/2019), LAQVREQUIMTE (UIDB/50006/2020), CICECO-Aveiro Institute of Materials (Ref.UID/CTM/50011/2020), (UID/CTM/50011/2019) and (UID/NAN/50024/2019); the projects: (UID/EMS/00481/2013), (PTDC/FISNAN/4662/2014), (PTDC/NAN-MAT/29317/2017), (PTDC/QUI-QFI/29319/2017), (LISBOA-01-0145-FEDER-029319) and (UIDB/00100/2020) through national funds and, where applicable, co-financed by European Union, FEDER, QREN, and COMPETE within the PT2020 Partnership Agreement, and to the Portuguese NMR Network. RFM acknowledges FCT for his Junior Research Position (CEECIND/00553/2017) and C. I. M. Santos for her research contract (REF.IST-ID/95/2018). Authors also thank the Departamento de Quimica Organica of Universidade Federal Fluminense (UFF-Brazil), Fundacao de Amparo a Pesquisa do Estado do Rio de Janeiro-FAPERJ (grants 101.125/2018, 211.119/2019 and 201.754/2018) and Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-CAPES.