Drastic Solid‐State Fluorescence Enhancement Behaviour of Phenanthro[9,10‐<i>d</i>]imidazole‐Type Fluorescent Hosts upon Inclusion of Carboxylic Acids

Ooyama, Yousuke; Uwada, Kazuki; Kumaoka, Hironori; Yoshida, Katsuhira

doi:10.1002/ejoc.200900823

Cited by 13 publications

(3 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, recent works highlighted the interest of simple and small molecular weight D-π-A push-pull dipolar fluorophores, in which an electron donating group D is connected to an electron-withdrawing group A via a π-conjugated bridge, for the design of efficient solid-state emitters. [22][23][24][25][26][27] , [28][29][30][31] , [32][33][34][35][36][37][38][39] , [40] , [41] The permanent dipole moment associated with the D-π-A structure gives rise to strong dipole-dipole interactions that can induce specific organization and orientation of molecules in the solid-state and favors the formation of emissive aggregates. Moreover, since the fluorescence of such dipolar fluorophores is usually characterized by a large Stokes shift, red and even far-red emission wavelengths over 700 nm are accessible, providing appropriate combinations of electron-donor and acceptor groups.…”

Section: Introductionmentioning

confidence: 99%

Tuning the solid-state emission of small push-pull dipolar dyes to the far-red through variation of the electron-acceptor group

et al. 2018

View full text Add to dashboard Cite

Series of solid-state emitters based on the D-π-A dipolar structure and featuring various electron-donor and electron-acceptor groups were designed, and their spectroscopic properties studied. From weak emission in dilute solutions, intense emissions in aggregated state (AIE) and in the crystalline state were obtained. Analysis in light of crystal structures obtained by X-ray diffraction revealed specific crystal packing and presence of long chain of emitting aggregates. This simple molecular engineering around the D-π-A dipolar structure provides easy access to a wide range of effective solid-state emitters allowing modulation of emission wavelengths up to the near infrared (λem reaching 735 and 768 nm for compound 2f and 3f bearing the strongest electron-withdrawing group). Highlights • Library of small push-pull dipolar solid-state emitters has been obtained featuring three different electron-donor groups and various electro-acceptor groups. • New electron-acceptor groups based on substituted 2(5H)-furanone rings are presented. • Fluorescence properties in the aggregated state and in the solid-state are described, and correlated to the presence of specific aggregates in the crystal structure. • The best dyes displayed near-infrared emission in the solid-state with emission quantum yield of 11% at λem=735 nm and 4% at λem=768 nm. • Keywords Solid-state fluorescence; Push-pull dyes; Organic dyes; Near-infrared; Aggregation-induced emission; 2(5H)-furanone rings library of push-pull fluorophores featuring 4-(N,N-diphenylamino)phenyl-(Series 1, Chart 1), 9-ethyl-9H-carbazolyl-(Series 2) and 4-(9H-carbazol-9-yl)-(Series 3) as electron-donor groups and various electron-acceptor groups (A-J, Scheme 1), in particular 2(5H)-furanone rings with a weak electronwithdrawing group at the C2 position (G-J). If some of these acceptor groups such as indanedione (A), dicyanoisophorone (E) or TCF (F) are quite commonly used in several high efficiency solid-state emitters, [32, 38-41, 44-50] other 2(5H)-furanones have rarely been utilized as acceptors entities in dye design and only within the frame of non-linear optical chromophores design (acceptor group G).[51, 52] Chart 1. Structures of fluorophores 1a-1i, 2a-2j and 3b-3i. 2. Experimental 2.1 General Information Commercially available materials and reagent grade solvents were used as received. Microwave syntheses were conducted in 20 mL sealed tube on a Biotage Initiator 2.5 single-mode reactor using external IR temperature control. The reaction monitoring was performed by analytical thin-layer chromatography (TLC) on Merck 60 F254 precoated silica gel plate (0.2 mm thickness) with visualization using a UV lamp. Purification by column chromatography was carried out using 35-70 m silica gel. 1 H and 13 C NMR spectra were recorded at ambient temperature on a Bruker Advance 300, 400 or 500 operating at 300.1, 400.0 or 500.0 MHz for 1 H and 75.0, 101.00 or 125.0 MHz for 13 C, respectively. Chemical shifts are reported as δ values (ppm) with reference to the residual solvent peaks...

show abstract

Section: Introductionmentioning

confidence: 99%

Tuning the solid-state emission of small push-pull dipolar dyes to the far-red through variation of the electron-acceptor group

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Solid-state fluorescent organic compounds have been widely investigated owing to their broad application potential in different fields. One such material features an organic fluorescent host, which can exhibit fluorescence enhancement with a blue-shift emission upon the inclusion of solvent molecules, associated with CH−π and π–π interactions and modification to the intermolecular hydrogen bonds. − Ooyama et al reported that crystals of phenanthro[9,10- d ]imidazole P60 (Scheme ), a fluorescent host, exhibited sharp emission enhancement with a red-shift in the emission maximum upon the enclathration of carboxylic acids such as formic acid, acetic acid, and propionic acid . The resulting fluorescent clathrate structure was formed by the cocrystallization of carboxylic acid solutions and by solid (fluorescent host)–gas (carboxylic acid vapor) contact, as described by the authors.…”

Section: Dual-functional Fluorescent/colorimetric Sensors Based On Ph...mentioning

confidence: 99%

“…175−178 Ooyama et al reported that crystals of phenanthro [9,10d]imidazole P60 (Scheme 8), a fluorescent host, exhibited sharp emission enhancement with a red-shift in the emission maximum upon the enclathration of carboxylic acids such as formic acid, acetic acid, and propionic acid. 179 The resulting fluorescent clathrate structure was formed by the cocrystallization of carboxylic acid solutions and by solid (fluorescent host)− gas (carboxylic acid vapor) contact, as described by the authors.…”

Section: Fluorescent/colorimetric Sensors Based On Phenanthro[910-d]i...mentioning

confidence: 99%

Aryl-Phenanthro[9,10-d]imidazole: A Versatile Scaffold for the Design of Optical-Based Sensors

et al. 2022

View full text Add to dashboard Cite

Fluorescent and colorimetric sensors are important tools for investigating the chemical compositions of different matrices, including foods, environmental samples, and water. The high sensitivity, low interference, and low detection limits of these sensors have inspired scientists to investigate this class of sensing molecules for ion and molecule detection. Several examples of fluorescent and colorimetric sensors have been described in the literature; this Review focuses particularly on phenanthro [9,10d]imidazoles. Different strategies have been developed for obtaining phenanthro [9,10d]imidazoles, which enable modification of their optical properties upon interaction with specific analytes. These sensing responses usually involve changes in the fluorescence intensity and/or color arising from processes like photoinduced electron transfer, intramolecular charge transfer, intramolecular proton transfer in the excited state, and Forster resonance energy transfer. In this Review, we categorized these sensors into two different groups: those bearing formyl groups and their derivatives and those based on other molecular groups. The different optical responses of phenanthro [9,10-d]imidazole-based sensors upon interaction with specific analytes are discussed.

show abstract

Synthesis of Carbazole‐Type D‐π‐A Fluorescent Dyes Possessing Solid‐State Red Fluorescence Properties

Ooyama¹,

Sugiyama²,

Oda³

et al. 2012

Eur J Org Chem

Self Cite

View full text Add to dashboard Cite

Carbazole‐type donor‐π‐acceptor (D‐π‐A) fluorescent dyes (SO1 and SO2), each containing a diphenylamino system as an electron‐donating group and a nitro moiety as an electron‐accepting group, have been designed and synthesized, and their photophysical properties in solution and in the solid state have been investigated. The absorption and fluorescence properties of SO1 and SO2 in solution are similar, and both dyes exhibited moderate fluorescence quantum yields. In the solid state, however, the dye SO2, with a butyl substituent on the carbazole ring, exhibited red fluorescence at around 620 nm, whereas the dye SO1, with no substituent on the carbazole ring, did not exhibit these solid‐state fluorescence properties. Furthermore, the dye SO2 exhibited weak mechanofluorochromic (MFC) properties: grinding of as‐recrystallized dyes induces slight bathochromic shifts of the fluorescence excitation and emission maxima. To elucidate the effects of molecular and crystal structures on the solid‐state fluorescence properties, we performed semiempirical molecular orbital calculations (PM3 and INDO/S) and single‐crystal X‐ray structural analysis. The X‐ray crystal structures of SO1 and SO2 demonstrated that a continuous intermolecular π‐stacking between the fluorophores was observable in the crystal structure of SO1, but not in that of SO2. The MO calculations revealed that SO1 and SO2 have similarly large dipole moments in the ground state (μg ≈ 8 D). The relationship between the observed solid‐state photophysical properties and the molecular and crystal structures of the carbazole‐type D‐π‐A fluorescent dyes are discussed on the basis of experimental results and MO calculations. It is found that the formation of a continuous intermolecular π‐stacking between the fluorophores causes a drastic fluorescence quenching in the solid state and that D‐π‐A fluorescent dyes with very large dipole moments can reduce the MFC properties, due to strong dipole–dipole interactions between the fluorophores in the solid state.

show abstract

Drastic Solid‐State Fluorescence Enhancement Behaviour of Phenanthro[9,10‐d]imidazole‐Type Fluorescent Hosts upon Inclusion of Carboxylic Acids

Cited by 13 publications

References 33 publications

Tuning the solid-state emission of small push-pull dipolar dyes to the far-red through variation of the electron-acceptor group

Tuning the solid-state emission of small push-pull dipolar dyes to the far-red through variation of the electron-acceptor group

Aryl-Phenanthro[9,10-d]imidazole: A Versatile Scaffold for the Design of Optical-Based Sensors

Synthesis of Carbazole‐Type D‐π‐A Fluorescent Dyes Possessing Solid‐State Red Fluorescence Properties

Contact Info

Product

Resources

About