30 research outputs found
Regulating Signal Enhancement with Coordination-Coupled Deprotonation of a Hydrazone Switch
Proton relay plays an important role in many biocatalytic pathways. In order to mimic such processes in the context of molecular switches, we developed coordination-coupled deprotonation (CCD) driven signaling and signal enhancement sequences. This was accomplished by using the zinc(ii)-initiated CCD of a hydrazone switch to instigate an acid catalyzed imine bond hydrolysis that separates a quencher from a fluorophore thus leading to emission amplification. Because CCD is a reversible process, we were able to show that the catalysis can be regulated and turned “on” and “off” using a metalation/demetalation cycle
Direct formation of fullerene monolayers using [4+2] Diels-Alder cycloaddition.
International audienceThe formation of covalent C(60) monolayers through [4+2] Diels-Alder cycloaddition between C(60) and anthracene monolayers grafted onto a silicon oxide surface was investigated by ellipsometry, fluorescence and by atomic force microscopy
Sperm Motility Regulatory Proteins: A Tool to Enhance Sperm Quality
Sperm forward motility is an essential parameter in mammalian fertilization. Studies from our laboratory have identified and characterized a few unique sperm motility regulatory proteins/glycoproteins from the male reproductive fluids and mammalian blood serum. The purified sperm motility-initiating protein (MIP) from caprine epididymal plasma as well as the forward motility-stimulating factor (FMSF) and motility-stimulating protein (MSP) from buffalo and goat serum, respectively, have high efficacy to initiate or increase motility in nonmotile or less motile sperm. Antibody of sperm motility inhibitory factor (MIF-II) has the high potential to enhance sperm vertical velocity and forward motility by increasing intracellular cyclic adenosine monophosphate (cAMP) level. The appearance and disappearance of D-galactose–specific lectin and its receptor along the epididymis has been reported to be involved in motility regulation in spermatozoa. A novel synthetic cryopreservation method and role of lipid to protect membrane damage during cryopreservation have been demonstrated. Motility-promoting proteins may be extremely useful for improving cattle breeding and breeding of endangered species, thereby helping in enhanced production of animal products as well as in the conservation of animals. Isolated proteins and developed cryopreservation technology may also be beneficial in human infertility clinics to increase the chance of fertilization
Carbazole–Benzonitrile–Norbornadiene Conjugates for Photothermally Reversible Ambient Phosphorescence
Organic photoswitches have attracted
significant attention across
various fields, such as sensing, bioimaging, photopharmacology, molecular
machines, and solar energy storage. However, as a result of design
complexities, achieving photothermally reversible ambient phosphorescence
switching in the condensed state remains elusive. Herein, we explore
the impact of norbornadiene (NBD)/quadricyclane (QC) substitution
at position 5 of the benzonitrile acceptor covalently attached to
the carbazole donor on photothermally reversible luminescence switching.
Experimental investigations demonstrated that the CzN and TBCzN switches
exhibited photothermally reversible fluorescence switching in solution.
Moreover, in the condensed state, fluorescence and ambient phosphorescence
switching were observed as a result of a low singlet–triplet
(ΔEST) gap (CzN ⇆ CzQ, ΔESTCzN/CzQ = 0.05/0.28 eV; TBCzN ⇆ TBCzQ, ΔESTTBCzN/TBCzQ = 0.06/0.09
eV). Reversible ambient phosphorescence switching is primarily influenced
by modulation of acceptor conjugation resulting from NBD ⇆
QC switching. This approach may provide important clues for the design
of visible-light-absorbing photothermally reversible phosphorescent
materials
Carbazole–Benzonitrile–Norbornadiene Conjugates for Photothermally Reversible Ambient Phosphorescence
Organic photoswitches have attracted
significant attention across
various fields, such as sensing, bioimaging, photopharmacology, molecular
machines, and solar energy storage. However, as a result of design
complexities, achieving photothermally reversible ambient phosphorescence
switching in the condensed state remains elusive. Herein, we explore
the impact of norbornadiene (NBD)/quadricyclane (QC) substitution
at position 5 of the benzonitrile acceptor covalently attached to
the carbazole donor on photothermally reversible luminescence switching.
Experimental investigations demonstrated that the CzN and TBCzN switches
exhibited photothermally reversible fluorescence switching in solution.
Moreover, in the condensed state, fluorescence and ambient phosphorescence
switching were observed as a result of a low singlet–triplet
(ΔEST) gap (CzN ⇆ CzQ, ΔESTCzN/CzQ = 0.05/0.28 eV; TBCzN ⇆ TBCzQ, ΔESTTBCzN/TBCzQ = 0.06/0.09
eV). Reversible ambient phosphorescence switching is primarily influenced
by modulation of acceptor conjugation resulting from NBD ⇆
QC switching. This approach may provide important clues for the design
of visible-light-absorbing photothermally reversible phosphorescent
materials
Carbazole–Benzonitrile–Norbornadiene Conjugates for Photothermally Reversible Ambient Phosphorescence
Organic photoswitches have attracted
significant attention across
various fields, such as sensing, bioimaging, photopharmacology, molecular
machines, and solar energy storage. However, as a result of design
complexities, achieving photothermally reversible ambient phosphorescence
switching in the condensed state remains elusive. Herein, we explore
the impact of norbornadiene (NBD)/quadricyclane (QC) substitution
at position 5 of the benzonitrile acceptor covalently attached to
the carbazole donor on photothermally reversible luminescence switching.
Experimental investigations demonstrated that the CzN and TBCzN switches
exhibited photothermally reversible fluorescence switching in solution.
Moreover, in the condensed state, fluorescence and ambient phosphorescence
switching were observed as a result of a low singlet–triplet
(ΔEST) gap (CzN ⇆ CzQ, ΔESTCzN/CzQ = 0.05/0.28 eV; TBCzN ⇆ TBCzQ, ΔESTTBCzN/TBCzQ = 0.06/0.09
eV). Reversible ambient phosphorescence switching is primarily influenced
by modulation of acceptor conjugation resulting from NBD ⇆
QC switching. This approach may provide important clues for the design
of visible-light-absorbing photothermally reversible phosphorescent
materials
Carbazole–Benzonitrile–Norbornadiene Conjugates for Photothermally Reversible Ambient Phosphorescence
Organic photoswitches have attracted
significant attention across
various fields, such as sensing, bioimaging, photopharmacology, molecular
machines, and solar energy storage. However, as a result of design
complexities, achieving photothermally reversible ambient phosphorescence
switching in the condensed state remains elusive. Herein, we explore
the impact of norbornadiene (NBD)/quadricyclane (QC) substitution
at position 5 of the benzonitrile acceptor covalently attached to
the carbazole donor on photothermally reversible luminescence switching.
Experimental investigations demonstrated that the CzN and TBCzN switches
exhibited photothermally reversible fluorescence switching in solution.
Moreover, in the condensed state, fluorescence and ambient phosphorescence
switching were observed as a result of a low singlet–triplet
(ΔEST) gap (CzN ⇆ CzQ, ΔESTCzN/CzQ = 0.05/0.28 eV; TBCzN ⇆ TBCzQ, ΔESTTBCzN/TBCzQ = 0.06/0.09
eV). Reversible ambient phosphorescence switching is primarily influenced
by modulation of acceptor conjugation resulting from NBD ⇆
QC switching. This approach may provide important clues for the design
of visible-light-absorbing photothermally reversible phosphorescent
materials
Carbazole–Benzonitrile–Norbornadiene Conjugates for Photothermally Reversible Ambient Phosphorescence
Organic photoswitches have attracted
significant attention across
various fields, such as sensing, bioimaging, photopharmacology, molecular
machines, and solar energy storage. However, as a result of design
complexities, achieving photothermally reversible ambient phosphorescence
switching in the condensed state remains elusive. Herein, we explore
the impact of norbornadiene (NBD)/quadricyclane (QC) substitution
at position 5 of the benzonitrile acceptor covalently attached to
the carbazole donor on photothermally reversible luminescence switching.
Experimental investigations demonstrated that the CzN and TBCzN switches
exhibited photothermally reversible fluorescence switching in solution.
Moreover, in the condensed state, fluorescence and ambient phosphorescence
switching were observed as a result of a low singlet–triplet
(ΔEST) gap (CzN ⇆ CzQ, ΔESTCzN/CzQ = 0.05/0.28 eV; TBCzN ⇆ TBCzQ, ΔESTTBCzN/TBCzQ = 0.06/0.09
eV). Reversible ambient phosphorescence switching is primarily influenced
by modulation of acceptor conjugation resulting from NBD ⇆
QC switching. This approach may provide important clues for the design
of visible-light-absorbing photothermally reversible phosphorescent
materials
Biluminescence via Fluorescence and Persistent Phosphorescence in Amorphous Organic Donor(D<sub>4</sub>)–Acceptor(A) Conjugates and Application in Data Security Protection
Purely organic biluminescent
materials are of great interest due
to the involvement of both singlet and long-lived triplet emissions,
which have been rarely reported in bioimaging and organic light-emitting
diodes. We show two molecules 3,4,5,6-tetraphenyloxy-phthalonitrile
(<b>POP</b>) and 3,4,5,6-tetrakis-<i>p</i>-tolyloxy-phthalonitrile
(<b>TOP</b>), in which <b>POP</b> was found to exhibit
fluorescence and persistent room-temperature green phosphorescence
(pRTGP) in the amorphous powder and crystal states. Both <b>POP</b> and <b>TOP</b> show aggregation-induced emission in a tetrahydrofuran–water
mixture. We found in single-crystal X-ray analysis that intra- and
intermolecular lpÂ(O)···π interactions along with
Ď€Â(C = C)···πÂ(Cî—ĽN), hydrogen bond
(H–B), and C–H···π interactions
induce a head-to-tail slipped-stack arrangement in <b>POP</b>. In addition, the X-ray structure of <b>TOP</b> with a slipped-stack
arrangement induced by only Ď€Â(Cî—»C)···πÂ(Cî—ĽN)
and H–B interactions shows dim afterglow only in crystals.
These indicate that more noncovalent interactions found in <b>POP</b> may reinforce relatively efficient intersystem crossing
that leads to pRTGP. Given the unique green afterglow feature in amorphous
powder of <b>POP</b>, document security protection application
is achievable
Biluminescence via Fluorescence and Persistent Phosphorescence in Amorphous Organic Donor(D<sub>4</sub>)–Acceptor(A) Conjugates and Application in Data Security Protection
Purely organic biluminescent
materials are of great interest due
to the involvement of both singlet and long-lived triplet emissions,
which have been rarely reported in bioimaging and organic light-emitting
diodes. We show two molecules 3,4,5,6-tetraphenyloxy-phthalonitrile
(<b>POP</b>) and 3,4,5,6-tetrakis-<i>p</i>-tolyloxy-phthalonitrile
(<b>TOP</b>), in which <b>POP</b> was found to exhibit
fluorescence and persistent room-temperature green phosphorescence
(pRTGP) in the amorphous powder and crystal states. Both <b>POP</b> and <b>TOP</b> show aggregation-induced emission in a tetrahydrofuran–water
mixture. We found in single-crystal X-ray analysis that intra- and
intermolecular lpÂ(O)···π interactions along with
Ď€Â(C = C)···πÂ(Cî—ĽN), hydrogen bond
(H–B), and C–H···π interactions
induce a head-to-tail slipped-stack arrangement in <b>POP</b>. In addition, the X-ray structure of <b>TOP</b> with a slipped-stack
arrangement induced by only Ď€Â(Cî—»C)···πÂ(Cî—ĽN)
and H–B interactions shows dim afterglow only in crystals.
These indicate that more noncovalent interactions found in <b>POP</b> may reinforce relatively efficient intersystem crossing
that leads to pRTGP. Given the unique green afterglow feature in amorphous
powder of <b>POP</b>, document security protection application
is achievable