scholarly journals BODIPY Nanoparticles Functionalized With Lactose for Cancer-Targeted and Fluorescence Imaging-guided Photodynamic Therapy

2021 ◽  
Author(s):  
Duy Khuong Mai ◽  
Chanwoo Kim ◽  
Joomin Lee ◽  
Temmy Pegarro Vales ◽  
Isabel Wen Baldon ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Fluorescence Imaging ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Fluorescence Emission ◽  
Water Soluble ◽  
Anticancer Activities ◽  
Electron Withdrawing Group ◽  
High Fluorescence ◽  
Atom Effect

Abstract A series of four lactose-modified BODIPY photosensitizers (PSs) with different substituents (-I, -H, -OCH3, and -NO2) in the para-phenyl moiety attached to the meso-position of the BODIPY core were synthesized; the photophysical properties and photodynamic anticancer activities of these sensitizers were investigated, focusing on the electronic properties of the different substituent groups. Iodine substitution (BODIPY I) enhanced the intersystem crossing (ISC) to produce singlet oxygen (1O2) due to the heavy atom effect, and maintained a high fluorescence quantum yield (ΦF) of 45.3%. Substitution with the electron-donating group (-OCH3) (BODIPY OMe) resulted in a high 1O2 generation capability and a ΦF of 49.2% while substitution with the electron-withdrawing group (-NO2) led to the PeT process. Thus, instead of assisting ISC as typically expected, this BODIPY PS induced non-radiative charge recombination, prohibiting both fluorescence emission and 1O2 generation. The BODIPY PSs formed water-soluble nanoparticles (NPs) functionalized with lactose as liver cancer-targeting ligands. BODIPY I and OMe NPs showed good fluorescence imaging and PDT activity against various tumor cells (HeLa and Huh-7 cells). Collectively, the BODIPY NPs demonstrated high 1O2 generation capability and ΦF may create a new opportunity to develop useful imaging-guided PDT agents for tumor cells.

scholarly journals Heavy atom effects in the Paternò–Büchi reaction of pyrimidine derivatives with 4,4’-disubstituted benzophenones

2011 ◽  
Vol 7 ◽  
pp. 113-118 ◽  
Author(s):  
Feng-Feng Kong ◽  
Jian-Bo Wang ◽  
Qin-Hua Song
Keyword(s):  
Temperature Effects ◽  
Halogen Atom ◽  
Heavy Atom ◽  
Photochemical Efficiency ◽  
Pyrimidine Derivatives ◽  
Heavy Atoms ◽  
Electron Withdrawing Group ◽  
Photochemical Systems ◽  
Expected Increase ◽  
Atom Effect

The regioselectivity and the photochemical efficiency were investigated in the Paternò–Büchi reaction of 1,3-dimethylthymine (DMT) and 1,3-dimethyluracil (DMU) with benzophenone (1b) and some 4,4’-disubstituted derivatives (dimethoxy (1a), difluoro (1c), dichloro (1d), dibromo (1e) and dicyano benzophenone (1f)) that gives rise to two regioisomeric oxetanes, 2 and 3. The regioselectivity (the ratio of 2/3) decreased gradually for both DMT/DMU photochemical systems from 1a to 1f. That is, a halogen atom as an electron-withdrawing group (EWG) has a pronounced effect on the regioselectivity. However, the photochemical efficiency of the 1e systems did not show the expected increase, but decreased relative to systems with 1b. Temperature effects on the regioselectivity of 1b–e systems showed some interesting features for systems with heavy atoms (including the 1d and 1e systems), such as higher inversion temperatures, and an entropy-controlled regioselectively whereas the regioselectivity for two other systems (1b and 1c) is enthalpy–entropy controlled. A heavy atom effect is suggested to be responsible for these unusual phenomena based on the triplet-diradical mechanism of the Paternò–Büchi reaction.

Synthesis, characterization and photophysical properties of ferrocenyl and mixed sandwich cobaltocenyl ester linked meso-triaryl corrole dyads

2017 ◽  
Vol 21 (10) ◽  
pp. 646-657 ◽  
Author(s):  
B. Shivaprasad Achary ◽  
A. R. Ramya ◽  
Rajiv Trivedi ◽  
P. R. Bangal ◽  
L. Giribabu
Keyword(s):  
Transient Absorption ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Parent Compound ◽  
Fluorescence Emission ◽  
Soret Band ◽  
Transient Absorption Spectroscopy ◽  
Ferrocene Derivatives ◽  
Time Resolved ◽  
Design And Synthesis

We report here the design and synthesis of corrole-metallocene dyads consisting of a metallocene (either ferrocene (Dyad 1) or mixed sandwich [Formula: see text]-[C[Formula: see text]H[Formula: see text](COOH)]Co([Formula: see text]-C[Formula: see text]Ph[Formula: see text] (Dyad 2)) connected via an ester linkage at meso phenyl position. Both the dyads were characterized by [Formula: see text]H NMR, MALDI-TOF, UV-visible, fluorescence spectroscopies (steady-state, picosecond time-resolved), femtosecond transient absorption spectroscopy (fs-TA) and electrochemical methods. The absorption spectra of these dyads showed slight broadening and splitting of the Soret band that indicates a weak ground state interaction between the corrole macrocycle and metallocene part of the present donor–acceptor (D–A) system. However, in both the dyad systems, fluorescence emission of the corrole was quenched in polar solvents as compared to its parent compound 10-(4-hydroxyphenyl)-5,15-bis-(pentafluorophenyl ) corrole (Ph-Corr). The quenching was more pronounced in ferrocene derivatives than in cobaltocenyl derivatives. Transient absorption studies confirm the absence of photoinduced electron transfer from metallocene to correl for these dyad systems and the quenching of singlet state of corrole is found to enhance intersystem crossing due to heavy atom effect.

scholarly journals Fluorescence properties of halogenated mono-hydroxyl corroles: the heavy-atom effects

2009 ◽  
Vol 13 (12) ◽  
pp. 1221-1226 ◽  
Author(s):  
Lei Shi ◽  
Hai-Yang Liu ◽  
Han Shen ◽  
Jun Hu ◽  
Guo-Liang Zhang ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Halogen Atom ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Phenyl Group ◽  
Atomic Weight ◽  
Quantum Yields ◽  
Intersystem Crossing ◽  
Fluorescence Quantum Yields ◽  
Atom Effect

A series of mono-hydroxyl corrole bearing a fluorine (1), chlorine (2), bromine (3) and iodine (4) atom on its 10-phenyl group have been synthesized. Fluorescence spectroscopy shows that the halogen atom at meso-phenyl group of corroles exhibit significant heavy-atom effect on their photophysical properties. Fluorescence quantum yields and the lifetime of these corroles decrease with the increasing of the atomic weight of halogen atoms. The quenching of the fluorescence could be interpreted in terms of a heavy atom-induced increase in intersystem crossing from S1 to T1. The intersystem crossing rate constant of these corroles were also determined by transient fluorescence spectra.

The heavy atom effect on Zn(ii) phthalocyanine derivatives: a theoretical exploration of the photophysical properties

2015 ◽  
Vol 17 (36) ◽  
pp. 23595-23601 ◽  
Author(s):  
Marta E. Alberto ◽  
Bruna C. De Simone ◽  
Gloria Mazzone ◽  
Emilia Sicilia ◽  
Nino Russo
Keyword(s):  
Photodynamic Therapy ◽  
Electronic Spectra ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Spin Orbit ◽  
Matrix Elements ◽  
Triplet Energy ◽  
Energy Gaps ◽  
P Absorption ◽  
Atom Effect

Absorption electronic spectra, singlet–triplet energy gaps and spin–orbit matrix elements have been computed at DFT and TDDFT levels of theory for a series of substituted Zn(ii)-phthalocyanines (ZnPcs), recently proposed as potential photosensitizers in photodynamic therapy (PDT).

scholarly journals Revealing Internal Heavy Chalcogen Atom Effect on the Photophysics of Dibenzo[a,j]phenazine-Cored Donor–Acceptor–Donor Triad

2021 ◽  
Author(s):  
Shimpei Goto ◽  
Yuya Nitta ◽  
Nicolas Decarli ◽  
Leonardo Evaristo de Sousa ◽  
Patrycja Stachelek ◽  
...  
Keyword(s):  
Room Temperature ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Delayed Fluorescence ◽  
Room Temperature Phosphorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
Mechanochromic Luminescence ◽  
Atom Effect

<div><div><div><p>A new twisted donor–acceptor–donor (D–A–D) multi-photofunctional organic molecule comprising of phenoselenazine as the electron-donors (Ds) and dibenzo[a,j]phenazine (DBPHZ) as the electron-acceptor (A) has been developed. The developed selenium-incorporated D–A–D compound is featured with multi-color polymorphism, distinct mechanochromic luminescence, chemically-stimulated luminochromism, thermally-activated delayed fluorescence, and room- temperature phosphorescence. The internal heavy atom effect on the photophysical properties of the D–A–D system has been investigated through the comparison with the physicochemical properties of a previously developed sulfur analogue and a tellurium analogue.</p></div></div></div>

scholarly journals Revealing Internal Heavy Chalcogen Atom Effect on the Photophysics of Dibenzo[a,j]phenazine-Cored Donor–Acceptor–Donor Triad

2021 ◽  
Author(s):  
Shimpei Goto ◽  
Yuya Nitta ◽  
Nicolas Decarli ◽  
Leonardo Evaristo de Sousa ◽  
Patrycja Stachelek ◽  
...  
Keyword(s):  
Room Temperature ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Delayed Fluorescence ◽  
Room Temperature Phosphorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
Mechanochromic Luminescence ◽  
Atom Effect

<div><div><div><p>A new twisted donor–acceptor–donor (D–A–D) multi-photofunctional organic molecule comprising of phenoselenazine as the electron-donors (Ds) and dibenzo[a,j]phenazine (DBPHZ) as the electron-acceptor (A) has been developed. The developed selenium-incorporated D–A–D compound is featured with multi-color polymorphism, distinct mechanochromic luminescence, chemically-stimulated luminochromism, thermally-activated delayed fluorescence, and room- temperature phosphorescence. The internal heavy atom effect on the photophysical properties of the D–A–D system has been investigated through the comparison with the physicochemical properties of a previously developed sulfur analogue and a tellurium analogue.</p></div></div></div>

scholarly journals Switchable organoplatinum metallacycles with high quantum yields and tunable fluorescence wavelengths

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun-Long Zhu ◽  
Lin Xu ◽  
Yuan-Yuan Ren ◽  
Ying Zhang ◽  
Xi Liu ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Fluorescence Quenching ◽  
Materials Science ◽  
Heavy Atom ◽  
Quantum Yields ◽  
Heavy Atom Effect ◽  
Fluorescence Quantum Yields ◽  
Supramolecular Coordination ◽  
High Fluorescence ◽  
Atom Effect

Abstract The preparation of fluorescent discrete supramolecular coordination complexes (SCCs) has attracted considerable attention within the fields of supramolecular chemistry, materials science, and biological sciences. However, many challenges remain. For instance, fluorescence quenching often occurs due to the heavy-atom effect arising from the Pt(II)-based building block in Pt-based SCCs. Moreover, relatively few methods exist for tuning of the emission wavelength of discrete SCCs. Thus, it is still challenging to construct discrete SCCs with high fluorescence quantum yields and tunable fluorescence wavelengths. Here we report nine organoplatinum fluorescent metallacycles that exhibit high fluorescence quantum yields and tunable fluorescence wavelengths through simple regulation of their photoinduced electron transfer (PET) and intramolecular charge transfer (ICT) properties. Moreover, 3D fluorescent films and fluorescent inks for inkjet printing were fabricated using these metallacycles. This work provides a strategy to solve the fluorescence quenching problem arising from the heavy-atom effect of Pt(II), and offers an alternative approach to tune the emission wavelengths of discrete SCCs in the same solvent.

Synthesis, Characterization, and Photophysics of a New Trinuclear Mercury(II) Complex of 1,3,5-Triethynylbenzene

2006 ◽  
Vol 59 (7) ◽  
pp. 434 ◽  
Author(s):  
Li Liu ◽  
Wai-Yeung Wong ◽  
Cheuk-Lam Ho
Keyword(s):  
Excited State ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
High Energy ◽  
Intersystem Crossing ◽  
Spectroscopic Techniques ◽  
Triplet States ◽  
Ambient Conditions ◽  
Triplet Excited States ◽  
Atom Effect

A new trinuclear mercury(ii) complex of 1,3,5-triethynylbenzene [(MeHgC≡C)3(1,3,5-C6H3)] 1 was prepared in good yield by Hagihara’s dehydrohalogenation reaction of HgMeCl with [(HC≡C)3(1,3,5-C6H3)] under ambient conditions. This trimercury triacetylide complex’s structure was confirmed by common spectroscopic techniques and its photophysical properties were examined and compared with the isolobal gold(i) congener [{(PPh3)AuC≡C}3(1,3,5-C6H3)] 2. Our investigations indicate that the organic triplet emissions can be harvested by the heavy-atom effect of mercury which enables efficient intersystem crossing from the S1 singlet excited state to the T1 triplet excited state. The influence of Hg and Au centres on the phosphorescence efficiency and evolution of the lowest electronic singlet and triplet excited states is critically characterized. Both complexes 1 and 2 possess high-energy triplet states of 2.77–2.82 eV, in which the order of intersystem crossing rate follows the order Au > Hg.

The effect of substitutents at alkylsulfanyl/arylsulfanyl non-peripherally substituted phthalocyanines: Spectral and photophysical properties, basicity and photostability

2015 ◽  
Vol 19 (10) ◽  
pp. 1095-1106 ◽  
Author(s):  
Antonin Cidlina ◽  
Zuzana Pausimova ◽  
Miroslav Miletin ◽  
Petr Zimcik ◽  
Veronika Novakova
Keyword(s):  
Photophysical Properties ◽  
Heavy Atom ◽  
Blue Shift ◽  
Red Shift ◽  
Oxygen Production ◽  
Metal Free ◽  
Peripheral Position ◽  
Magnesium Complexes ◽  
Derivatives Of ◽  
Atom Effect

A series of magnesium, zinc and metal-free derivatives of non-peripherally substituted phthalocyanines (Pcs) bearing alkylsulfanyl or arylsulfanyl groups of different bulkiness was synthesized. Their spectral and photophysical properties including also the basicity of azomethine nitrogens and photostability were compared within the series as well as with similar peripherally substituted Pcs. Non-peripheral position of substituents led to the 70[Formula: see text]nm red-shift of Q-band in comparison to the peripherally substituted Pcs. However, unexpected blue-shift of approximately 50[Formula: see text]nm was observed in the series of non-peripherally substituted Pcs for the most bulky tert-butylsulfanyl derivative caused probably by extreme distortion of the macrocycle. The substitution had no effect on photophysical properties and compounds reached [Formula: see text] values 0.74–0.76 and [Formula: see text] 0.053–0.080 for zinc complexes, and [Formula: see text] 0.47–0.51 and [Formula: see text] 0.10–0.17 for magnesium complexes following the rule of heavy atom effect. Generally, non-peripherally substituted Pcs possessed improved singlet oxygen production in comparison to peripherally substituted ones. The photostability of the target compounds decreased with the red-shift of their absorption maxima with the arylsulfanyl derivatives being less photostable. The basicity of azomethine nitrogens was clearly dependent on the position and the character of substituent. Thus, non-peripherally substituted Pcs showed extraordinary increased basicity over the peripherally substituted ones with the most pronounced effect at alkylsulfanyl derivatives.

Sign in / Sign up

Export Citation Format

Share Document