Jingbai Li

Shenzhen Polytech · Hoffmann Institute of Advanced Materials

Storing solar energy is a vital component of using renewable energy sources to meet the growing demands of the global energy economy. Molecular solar thermal (MOST) energy storage is a promising means to store solar energy with on-demand energy release. The light-induced isomerization reaction of norbornadiene (NBD) to quadricyclane (QC) is of grea...

Storing solar energy is a vital component of using renewable energy sources to meet the growing demands of the global energy economy. Molecular solar thermal (MOST) energy storage is a promising means to store solar energy with on-demand energy release. The light-induced isomerization reaction of norbornadiene (NBD) to quadricyclane (QC) is of grea...

We report the synthesis and evaluation of novel chelating agents for zirconium-89 (89Zr) with positron emission tomography (PET) imaging applications. New chelating agents NODHA, NOTHA, and NODHA-PY were constructed on 1,4,7-triazacyclononane (TACN) and possess hydroxamic acid or a pyridine ring as an acyclic binding moiety. The new chelating agent...

ConspectusPhotochemical reactions are of great importance in chemistry, biology, and materials science because they take advantage of a renewable energy source, mild reaction conditions, and high atom economy. Light absorption can excite molecules to a higher energy electronic state of the same spin multiplicity. The following nonadiabatic processe...

The photochemistry of benzene is complex and non‐selective because numerous mechanistic pathways are accessible in the ground and excited states. Fluorination is a known strategy to increase the chemoselectivities for Dewar‐benzenes via 4π‐disrotatory electrocyclization. However, the origin of the chemo‐ and regioselectivities of fluorobenzenes rem...

Two phenylene based geometrical/isomeric triplet ortho- and para–dyads (o–3 and p–3, respectively) were synthesized and fully characterized using advanced photophysical tools and computations. In dyad o–3, the through-space donor-acceptor interactions led to simultaneous triplet energy transfer and charge transfer with identical kinetics. On the ot...

The photochemistry of benzene is complex and non-selective because numerous mechanistic pathways are accessible in the ground- and excited-states. Fluorination is a known strategy to increase the chemoselectivities for Dewar-benzenes via 4π-disrotatory electrocyclization. However, the origin of the chemo- and regioselectivities of fluorobenzenes re...

Photochemical [2+2]-photocycloadditions are used to efficiently access strained organic molecular architectures, storing solar energy in chemical bonds. Functionalized [3]-ladderenes have been shown to undergo [2+2]-photocycloadditions to afford cubanes, an energy-dense class of organic molecules. The substituents (e.g., methyl, trifluoromethyl, an...

Photochemical [2+2]-photocycloadditions are used to efficiently access strained organic molecular architectures, storing solar energy in chemical bonds. Functionalized [3]-ladderenes have been shown to undergo [2+2]-photocycloadditions to afford cubanes, an energy-dense class of organic molecules. The substituents (e.g., methyl, trifluoromethyl, an...

Photochemical reactions are widely used by academia and industry to construct complex molecular architectures via mechanisms that are often inaccessible by other means.

Photochemical reactions exemplify “green” chemistry and are an essential tool for synthesizing highly strained molecules under mild conditions with light. The light-promoted denitrogenation of bicyclic azoalkanes affords functionalized, stereoenriched bicyclo[1.1.0]butanes. These reactions were revisited with multireference calculations and non-adi...

p>Photochemical reactions exemplify ‘green’ chemistry and are essential for synthesizing highly strained molecules with mild conditions with light. The light-promoted denitrogenation of bicyclic azoalkanes affords functionalized, stereoenriched bicyclo[1.1.0]butanes. We revisited these reactions with multireference calculations and non-adiabatic mo...

p>Photochemical reactions are being increasingly used to construct complex molecular architectures with mild and straightforward reaction conditions. Computational techniques are increasingly important to understand the reactivities and chemoselectivities of photochemical isomerization reactions because they offer molecular bonding information alon...

Cu(i) and Au(i) ions, capped with an N-heterocyclic carbene (NHC), react with (TMS)3P7 (TMS = trimethyl-silyl) to afford an η4-coordinated anion [NHCDippCu-P7(TMS)]- and a neutral trinuclear complex (NHCDippAu)3P7. Protecting the P7 cage with the TMS groups is instrumental in controlling the course of these reactions.

Sunlight is a renewable energy source that can be stored in chemical bonds using photochemical reactions. The synthesis of exotic and strained molecules is especially attractive with photochemical techniques because of the associated efficient and mild reaction conditions. We have used complete active space self-consistent field (CASSCF) calculatio...

Optical imaging in the shortwave infrared region (SWIR, 1000-2000 nm) provides high-resolution images in complex systems. Here we explore substituent placement on dimethylamino flavylium polymethine dyes, a class of SWIR fluorophores. We find that the position of the substituent significantly affects the λmax and fluorescence quantum yield. Quantum...

p>Sunlight is a renewable energy source that can be stored in chemical bonds using photochemical reactions. The synthesis of exotic and strained molecules is especially attractive with photochemical techniques because of the associated efficient and mild reaction conditions. We have used complete active space self-consistent field (CASSCF) calculat...

We report the synthesis and photophysical characterization of a triplet donor-acceptor dyad (3), which was constructed from a quinoidal naphthalene thioamide triplet sensitizer 1 and a perylene derivative 2 as the acceptor. The dyad of interest exhibits convoluted photophysical characteristics from the donor and acceptor chromophores. The kinetic a...

The Cover Feature shows Lawesson reagent mediated selective transformations of pi‐expanded acene diimides to afford the corresponding quinoidal triplet chromophores. The comprehensive photophysics and aromaticity of the these chromophores were also described in the present work. While the pi‐expansion strategy allowed to create long‐lived triplet e...

Nanoscale localization of electromagnetic fields using metallic nanostructures can catalyze chemical reactions in their immediate vicinity. Local optical field confinement and enhancement is also exploited to attain single molecule detection sensitivity in surface and tip-enhanced Raman (TER) spectroscopy. In this work, we observe and investigate t...

We report the synthesis and photophysical characterization of π‐expanded quinoidal triplet chromophores which exhibits attractive light‐harvesting properties. The kinetic of the triplet excited state of quinoidal benzotetraphene 2 was found to be one order of magnitude higher than the lifetime of 3(1)* from the less conjugated parent chromophore 1....

The comprehensive theoretical investigation of stability of functionalized corannulene cations [R-C20 H10 ]+ with respect to two alternative bond-breaking mechanisms, namely, homolytic or radical ([R-C20 H10 ]+ → R• + C20 H10+• ) and heterolytic or cationic ([R-C20 H10 ]+ → R+ + C20 H10 ), was accomplished. The special focus was on the influence of...

One‐electron reduction of corannulene, C20H10, with Li metal in diglyme resulted in crystallization of [{Li+(diglyme)2}4(C20H10•−)2(C20H10−C20H10)2−] (1), as revealed by single crystal X‐ray diffraction. This hybrid product contains two corannulene monoanion‐radicals along with a dianionic dimer, crystallized with four Li+ ions wrapped by diglyme m...

Raman and infrared (IR) are two complementary vibrational spectroscopy techniques that enable label-free, noninvasive, and nondestructive structural characterization of analyzed specimens. IR spectroscopy is broadly utilized in various research areas ranging from food chemistry and agriculture to geology and medicine. Recently, Raman spectroscopy (...

In-depth theoretical analysis of the consequences of methylation of the rim sites of corannulene is completed. The full set of derivatives ranging from parent C20H10 to fully substituted C20(CH3)10 has been evaluated, revealing consistent trends along the series. The controlled one-electron chemical reduction of selected methylated corannulenes, su...

In this study, the first comprehensive theoretical investigation of the stability of functionalized fullerene‐based cations [R‐C60]⁺ and its relationship with the nature of the attached R‐group was performed. C60‐Fullerene core was functionalized with an alkyl group of different length (R = (CH2)nCH3, where n = 0–9). This set was further complement...

The first convex cesium-bound complex with a bowl-shaped carbanion, namely [{Cs⁺(dc-18-crown-6)}(C21H11–)] (1), has been isolated and crystallographically characterized. In the structure of 1, the cesium ion capped by dicyclohexano-18-crown-6 ether coordinates to the deprotonated five-membered ring of a sumanenyl bowl in an exo fashion with the Cs·...

We report a novel reductive desulfurization reaction involving π-acidic naphthalene diimides (NDI) 1 using thionating agents such as Lawesson’s reagent. Along with the expected thionated NDI derivatives 2–6, new heterocyclic naphtho-p-quinodimethane compounds 7 depicting broken/reduced symmetry were successfully isolated and fully characterized. Em...

The first comprehensive theoretical exploration of the energetics of the interaction between π-ligands with isolated multiple carbon-carbon bonds (acetylene and ethylene), aromatic (benzene), planar polyaromatic (naphthalene, acenaphthalene, pyrene), curved polyaromatic (corannulene) and closed-cage C60-fullerene systems and Lewis acidic [Rh2(O2CCF...

The electronic structure, reduction limits, and coordination abilities of a bowl-shaped polycyclic aromatic hydrocarbon, indacenopicene (C26H12, 1), have been investigated for the first time using a combination of theoretical and experimental tools. A direct comparison with the prototypical corannulene bowl (C20H10, 2) revealed the effects of carbo...

N-Heterocyclic carbenes (NHC's) are known to serve as efficient substrates for the stabilization of various transient species possessing low-valent Group?14 elements and for the generation of double E=C bonds. Herein, we report that the thermal tri- and tetramerizations of pyridoannulated silylene 1 lead to the formation of remarkably stable silene...

N-Heterocyclic carbenes (NHC's) are known to serve as efficient substrates for the stabilization of various transient species possessing low-valent Group?14 elements and for the generation of double E=C bonds. Herein, we report that the thermal tri- and tetramerizations of pyridoannulated silylene 1 lead to the formation of remarkably stable silene...

The first comprehensive theoretical study of stability of hub-functionalized corannulene cations [R-C20 H10 ](+) as the function of the nature of R-group was accomplished. The initial set of linear alkyl R-group of different length (R=(CH2 )n CH3 , n = 0-9) was augmented by groups which form stable organic cations, such as tert-butyl, isopropyl, al...

A variety of optically active secondary N,N-disubstituted β-halo amines are efficiently synthesized from N,N-disubstituted alaninol via formation and ring opening (at the more hindered carbon) of aziridinium ions by halides.

The first comprehensive theoretical investigation of aromaticity in functionalized corannulene cations of general formula [CH3-C20H10]+ was accomplished. The experimentally known system [CH3-hub-C20H10]+ was augmented by two other possible isomers, namely, rim- and spoke-ones. Changes in aromaticity, when going from neutral corannulene to its funct...

Aziridinium ions are useful reactive intermediates for the synthesis of enantiomerically enriched building blocks. However, N,N-dialkyl aziridinium ions are relatively underutilized in the synthesis of optically active molecules as compared to other three-membered ring cogeners, aziridines and epoxides. The characterization of both optically active...

Hot spots in superconducting radio-frequency (SRF) cavities at the Advanced Photon Source are a problem found to be at least partially caused by surface carbon and oxygen based molecules. This study illustrates how Density Functional Theory (DFT) can be used to compare theoretical spectra of various molecules to the experimental results, which can...

Experimentally known adducts of SO2 with transition metal complexes have distinct geometries. In the present paper, we demonstrate by a bonding analysis that this is a direct consequence of sulfur dioxide acting as an acceptor in one set, square-planar complexes of d(8) and linear two-coordinated complexes of d(10) transition metals, and as a donor...