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Cycloheptatrienyl (tropyl) molecules are representative non‐alternant hydrocarbons that offer interesting chemistry because of their unique structures and properties. However, there have been a limited number of polycyclic aromatic tropyl cations and radicals reported in the literature. Herein, we report the synthesis of a series of azahomocorannulene derivatives, where the key reactions are a 1,3‐dipolar cycloaddition of polycyclic aromatic azomethine ylides with dibenzotropone and a subsequent palladium‐catalyzed cyclization. X‐ray diffraction analysis revealed that the obtained azahomocorannulenyl cation and radical adopt planar structures and exhibit unique packing structures. Their electronic and optical properties were investigated experimentally and theoretically to reveal their aromatic character. [ABSTRACT FROM AUTHOR]

Sulfur‐embedded polycyclic aromatic compounds have been used as building blocks for numerous organic semiconductors over the past few decades. While the success is based on thiophene‐containing compounds, aromatic compounds that contain thiepine, a sulfur‐containing seven‐membered‐ring arene, has been less well investigated. Here we report the synthesis and properties of π‐extended pyrrole‐fused heteropine compounds such as thiepine and oxepine. A π‐extended pyrrole‐fused thiepine exhibited a "pitched π‐stacking" structure in the crystal, and exhibited a high charge carrier mobility of up to 1.0 cm2 V−1 s−1 in single‐crystal field‐effect transistors. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic molecules are promising functional materials for a wide range of applications, especially in organic electronics. However, their largely hydrophobic nature has impeded further applications. As such, imparting high solubility/hydrophilicity to polycyclic aromatic molecules leads to a breakthrough in this research field. Herein, we report the synthesis of diazapentabenzocorannulenium, a cationic nitrogen‐embedded buckybowl bearing a central imidazolium core, by a bottom‐up strategy from polycyclic aromatic azomethine ylide. X‐ray crystallography analyses have revealed a bowl‐shaped molecular structure that is capable of forming charge‐segregated one‐dimensional columns by bowl‐in‐bowl packing. In addition to its fluorescence capabilities and high dispersibility in water, the molecule was found to selectively localize in the mitochondria of various tumor cells, showing potential as viable mitochondria‐selective fluorescent probes. [ABSTRACT FROM AUTHOR]

The ability to rationally design and predictably construct crystalline solids has been the hallmark of crystal engineering research. To date, numerous examples of multicomponent crystals comprising organic molecules have been reported. However, the crystal engineering of cocrystals comprising both organic and inorganic chemical units is still poorly understood and mostly unexplored. Here, we report a new diverse set of higher‐order cocrystals (HOCs) based on the structurally versatile—yet largely unexplored—phosph(V/V)azane heterosynthon building block. The novel ternary and quaternary cocrystals reported are held together by synergistic and orthogonal intermolecular interactions. Notably, the HOCs can be readily obtained either via sequential or one‐pot mechanochemical methods. Computational modelling methods reveal that the HOCs are thermodynamically driven to form and that their mechanical properties strongly depend on the composition and intermolecular forces in the crystal, offering untapped potential for optimizing material properties. [ABSTRACT FROM AUTHOR]

A facile approach to assemble catalase‐like photosensitizing nanozymes with a self‐oxygen‐supplying ability was developed. The process involved Fe3+‐driven self‐assembly of fluorenylmethyloxycarbonyl (Fmoc)‐protected amino acids. By adding a zinc(II) phthalocyanine‐based photosensitizer (ZnPc) and the hypoxia‐inducible factor 1 (HIF‐1) inhibitor acriflavine (ACF) during the Fe3+‐promoted self‐assembly of Fmoc‐protected cysteine (Fmoc‐Cys), the nanovesicles Fmoc‐Cys/Fe@Pc and Fmoc‐Cys/Fe@Pc/ACF were prepared, which could be disassembled intracellularly. The released Fe3+ could catalyze the transformation of H2O2 enriched in cancer cells to oxygen efficiently, thereby ameliorating the hypoxic condition and promoting the photosensitizing activity of the released ZnPc. With an additional therapeutic component, Fmoc‐Cys/Fe@Pc/ACF exhibited higher in vitro and in vivo photodynamic activities than Fmoc‐Cys/Fe@Pc, demonstrating the synergistic effect of ZnPc and ACF. [ABSTRACT FROM AUTHOR]

Published studies of layered (2D) (100)‐oriented hybrid lead‐bromide perovskites evidence a correlation between increased inter‐octahedral (Pb‐Br‐Pb) distortions and the appearance of broadband white light emission. However, the impact of distortions within their constituent [PbBr6]4− octahedra has yet to be assessed. Herein, we report two new (100)‐oriented 2D Pb‐Br perovskites, whose structures display unusually high intra‐octahedral distortions, whilst retaining minimal inter‐octahedral distortions. Using a combination of temperature‐dependent, power‐dependent and time‐resolved photoluminescence spectroscopic measurements, we show that increased intra‐octahedral distortion induces exciton localization processes and leads to formation of multiple photoinduced emissive colour centres. Ultimately, this leads to highly Stokes‐shifted, ultrabroad white light emission at room temperature. [ABSTRACT FROM AUTHOR]

Clinical translation of curcumin has been highly obstructed by the rapid degradation and poor tissue absorption of this agent. Herein, we report on the generation of supramolecular curcumin nanoagents through amino acid coordination driven self‐assembly to simultaneously increase the biological stability and tumor accumulation of curcumin. The biological stability of curcumin was significantly improved both through coordination and through molecular stacking. The sizes of these nanoagents can be readily manipulated to facilitate tumor accumulation. These favorable therapeutic features, together with high drug‐loading capacities and responses to pH and redox stimuli, substantially enhanced the antitumor activity of curcumin without discernible side effects. Hence, supramolecular curcumin nanoagents may hold promise in moving forward the clinical application of curcumin as an effective anticancer drug. Special agents on the job: Supramolecular curcumin nanoagents were fabricated by amino acid coordination driven self‐assembly (see picture). The biological stability of curcumin was significantly improved through both coordination and molecular stacking in the nanoagents, the size of which could be readily manipulated. These favorable therapeutic features substantially enhanced the antitumor activity of curcumin without discernible side effects. [ABSTRACT FROM AUTHOR]

Metal‐free activation of homoatomic E−E σ bonds (E=P, B) in white phosphorus (P4) and bis(catecholato)diboron (B2cat2) with a 1,2‐diboraallene 1 is reported. The 1:1 and 1:2 reactions of P4 with 1 afford BnP4 cages (2: n=2, 3: n=4), whereas a stoichiometric mixture of 1 and B2cat2 undergoes homonuclear catenation through the addition of the B−B σ bond of B2cat2 across the B=B double bond of 1 (i.e. diboration), which leads to the formation of a tetraborane (4) featuring a B4 chain. Metal‐free activation of homoatomic E−E σ bonds (E=P, B) in white phosphorus (P4) and bis(catecholato)diboron (B2cat2) with a 1,2‐diboraallene is reported. The former affords BnP4 cages (n=2, 4), whereas the latter leads to the formation of a tetraborane featuring a B4 chain through homonuclear catenation. [ABSTRACT FROM AUTHOR]

Abstract: Success in obtaining higher‐order twistarenes with precise structures is very important for fundamentally understanding the relationship between the structures and physical properties/optoelectronic applications. In this research, by using the advantages from a retro‐Diels–Alder process (clean reaction) and the cross‐conjugated nature of the pyrene unit, a novel dodeca‐twistarene was prepared for the first time. Its structure, confirmed by single‐crystal XRD analysis, indicates that it possesses a twisted angle (≈30°), and two neighboring molecules in the crystal lattice are perpendicular to each other because of the twisted character and the strong intermolecular CH–π interactions. However, its basic physicochemical properties suggest its instability in air derives from its elevated HOMO energy level, although NICS calculations confirm that the pyrene units contribution poorly to the π conjugation of the overall molecule. [ABSTRACT FROM AUTHOR]

Abstract: Weak intermolecular interactions in organic semiconducting molecular crystals play an important role in determining molecular packing and electronic properties. Single crystals of metal‐free and metal phthalocyanines were synthesized to investigate how the coordination of the central metal atom affects their molecular packing and resultant electronic properties. Single‐crystal field‐effect transistors were made and showed a hole mobility order of ZnPc>MnPc>FePc>CoPc>CuPc>H2Pc>NiPc. Density functional theory (DFT) and 1D polaron transport theory reach a good agreement in reproducing the experimentally measured trend for hole mobility. Additional detail analysis at the DFT level suggests the metal atom coordination into H2Pc planes can tune the hole mobility via adjusting the intermolecular distances along the shortest axis with closest parallel π stackings. [ABSTRACT FROM AUTHOR]

Abstract: Weak intermolecular interaction in organic semiconducting molecular crystals plays an important role in molecular packing and electronic properties. Here, four five‐ring‐fused isomers were rationally designed and synthesized to investigate the isomeric influence of linear and angular shapes in affecting their molecular packing and resultant electronic properties. Single‐crystal field‐effect transistors showed mobility order of 5,7‐ICZ (3.61 cm2 V−1 s−1) >5,11‐ICZ (0.55 cm2 V−1 s−1) >11,12‐ICZ (ca. 10−5 cm2 V−1 s−1) and 5,12‐ICZ (ca. 10−6 cm2 V−1 s−1). Theoretical calculations based on density functional theory (DFT) and polaron transport model revealed that 5,7‐ICZ can reach higher mobilities than the others thanks to relatively higher hole transfer integral that links to stronger intermolecular interaction due to the presence of multiple NH⋅⋅⋅π and CH⋅⋅⋅π(py) interactions with energy close to common NH⋅⋅⋅N hydrogen bonds, as well as overall lower hole‐vibrational coupling owing to the absence of coupling of holes to low frequency modes due to better π conjugation. [ABSTRACT FROM AUTHOR]

Abstract: An annulated 1,3,2,5‐diazadiborinine with 14 π electrons has been synthesized and fully characterized. Experimental and computational studies revealed that this compound features a rather small HOMO–LUMO gap, which leads to enhanced reactivity towards small molecules. Thus, the 1,3,2,5‐diazadiborinine readily cleaves the H−H bond of dihydrogen and an N−H bond of ammonia under mild conditions. Moreover, it reacts with 2,6‐dimethylphenylisonitrile in a [4+1] cycloaddition at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: One‐electron oxidation of 1,4,2,5‐diazadiborinine 1 has been studied. While the reaction of 1 a bearing phenyl groups on the B atoms with AgAl{OC(CF3)3}4 afforded a complex mixture, the same oxidation reaction with 1 b featuring bulky mesityl substituents on the B atoms rendered the corresponding cation radical 2 b as an isolable species. X‐ray diffraction analysis, EPR spectroscopy, and DFT calculations of 2 b revealed the delocalization of the unpaired electron over the entire π‐system of 2 b, as well as a large spin density (0.76 in total) on the two equivalent boron atoms. The chemical trapping reaction of 2 b with p‐benzoquinone and triphenyltin hydride afforded the dicationic species 3 containing two newly formed B−O bonds and the monocationic product 2b‐H containing a B−H bond, respectively, thus confirming the boron‐centered radical reactivity of 2 b. [ABSTRACT FROM AUTHOR]

Abstract: Determination of molecular structural parameters of hydrophobic cholesterol–naphthalimide conjugates for water binding capabilities as well as their moisture‐sensitive supramolecular self‐assembly were revealed. Water binding was a key factor in leading trace water‐induced crystallization against gelation in apolar solvent. Ordered water molecules entrapped in self‐assembly arrays revealed by crystal structures behave as hydrogen‐bonding linkers to facilitate three‐dimensional growth into crystals rather than one‐dimensional gel nanofibers. Water binding was also reflected on the supramolecular chirality inversion of vesicle self‐assembly in aqueous media via heating‐induced dehydration. Structural parameters that favor water binding were evaluated in detail, which could help rationally design organic building units for advancing soft materials, crystal engineering, and chiral recognition. [ABSTRACT FROM AUTHOR]

Diverse skeletal transformations of 1,4,2-diazaboroles through ring expansion, photoisomerization, and retrocyclization led to the isolation of various B,N-dihydroindole (compounds 3 and 6), 1,3-azaborolidin-2-imine (compound 7), and 1,4,2-diazaborol-3-imine derivatives (compound 11). [ABSTRACT FROM AUTHOR]

The reaction of the NHC-disilicon(0) complex [(IAr)Si=Si(IAr)] ( 1, IAr=:C{N(Ar)C(H)}2, Ar=2,6- iPr2C6H3) with two equiv of elemental Te in toluene at room temperature for three days afforded a mixture of the first dimeric NHC-silicon monotelluride [(IAr)Si=Te]2 ( 2) and its isomeric complex [(IAr)Si(μ-Te)Si(IAr)=Te] ( 3). When the same reaction was performed for ten days, only 3 was isolated from the reaction mixture. Compound 1 reacted with four equiv of elemental Te in toluene for four weeks, which proceeded through the formation of 2, 3 and the NHC-disilicon tritelluride complex [{(IAr)Si(=Te)}2Te] ( 5-Te), to form the dimeric NHC-silicon ditelluride [(IAr)Si(=Te)(μ-Te)]2 ( 4). The reactions are in line with theoretical mechanistic studies for the formation of 4. Compound 3 reacted with one equiv of elemental sulfur in toluene to form the first NHC-disilicon sulfur ditelluride complex [{(IAr)Si(=Te)}2S] ( 5-S). [ABSTRACT FROM AUTHOR]

The trapping of a silicon(I) radical with N-heterocyclic carbenes is described. The reaction of the cyclic (alkyl)(amino) carbene [cAACMe] (cAACMe=:C(CMe2)2(CH2)NAr, Ar=2,6- iPr2C6H3) with H2SiI2 in a 3:1 molar ratio in DME afforded a mixture of the separated ion pair [(cAACMe)2Si:.]+I− ( 1), which features a cationic cAAC-silicon(I) radical, and [cAACMe−H]+I−. In addition, the reaction of the NHC-iodosilicon(I) dimer [IAr(I)Si:]2 (IAr=:C{N(Ar)CH}2) with 4 equiv of IMe (:C{N(Me)CMe}2), which proceeded through the formation of a silicon(I) radical intermediate, afforded [(IMe)2SiH]+I− ( 2) comprising the first NHC-parent-silyliumylidene cation. Its further reaction with fluorobenzene afforded the CAr−H bond activation product [1-F-2-IMe-C6H4]+I− ( 3). The isolation of 2 and 3 confirmed the reaction mechanism for the formation of 1. Compounds 1- 3 were analyzed by EPR and NMR spectroscopy, DFT calculations, and X-ray crystallography. [ABSTRACT FROM AUTHOR]

Metal-free regioselective carboboration of arylnitriles with L2PhB: ( 1: L=oxazol-2-ylidene) catalyzed by Et3B afforded the unprecedented acyclic 2-aza-4-borabutadienes 2, thus demonstrating a new strategy to construct a B,C,N-mixed π-system involving B=C and C=N bonds. Thermal isomerization of 2 gave C-borylimines ( 3), and diverse reactivity of 2 a towards several substrates, such as H+, F+, O2, S, Se, and isonitriles, allowed construction of boron-containing heterocycles with various ring sizes, thus illustrating the utility of 2 as a synthetic building block. [ABSTRACT FROM AUTHOR]

Molecular evolution, with self-organization of simple molecules towards complex functional systems, provides a new strategy for biomimetic architectonics and perspectives for understanding the complex processes of life. However, there remain many challenges to fabrication of systems comprising different types of units, which interact with one another to perform desired functions. Challenges arise from a lack of stability, dynamic properties, and functionalities that reconcile with a given environment. A co-assembling fiber system composed of simple peptide and porphyrin is presented. This material is considered a prebiotic assembly of molecules that can be rather stable and flexibly self-functionalized with the assistance of visible light in a 'prebiotic soup'; acidic (pH 2), hot (70 °C), and mineral-containing (Na+, Ti4+, Pt2+, and so forth) water. The co-assembled peptide-porphyrin fiber, with self-mineralized reaction centers, may serve as a primitive photobacteria-like cellular model to achieve light harvesting, energy transfer, and ultimately sustainable hydrogen evolution. [ABSTRACT FROM AUTHOR]

An autoionization of germanium dichloride/dioxane complex with an imino-N-heterocyclic carbene ligand ( L) afforded a novel germyliumylidene ion, [( L)GeCl]+[GeCl3]−, which was fully characterized. Reduction of the germyliumylidene ion with potassium graphite produced a cyclic species [( L)Ge], which can be viewed as both a Ge0 species and a mesoionic germylene. X-ray diffraction analysis and computational studies revealed one of the lone pairs on the Ge atom is involved in the π system on the GeC2N2 five-membered ring. It was also confirmed that the nucleophilic behavior of [( L)Ge] as a two lone-pair donor. [ABSTRACT FROM AUTHOR]

An isolable phenylborylene species supported by two oxazol-2-ylidene ligands was synthesized and structurally characterized. Computational studies revealed the presence of lone-pair electrons on the boron atom in this molecule; therefore, there are eight electrons around the three-coordinate boron center. The nucleophilic property was confirmed by the reactions with trifluoromethanesulfonic acid and [(thf)Cr(CO)5], which gave the corresponding conjugate acid and a chromium-borylene complex, respectively. [ABSTRACT FROM AUTHOR]

The two-electron reduction of a Group 14-element(I) complex [RË⋅] (E=Ge, R=supporting ligand) to form a novel low-valent dianion radical with the composition [RË:]. 2− is reported. The reaction of [LGeCl] ( 1, L=2,6-(CHNAr)2C6H3, Ar=2,6- iPr2C6H3) with excess calcium in THF at room temperature afforded the germylidenediide dianion radical complex [LGe]. 2−⋅Ca(THF)32+ ( 2). The reaction proceeds through the formation of the germanium(I) radical [LGe⋅], which then undergoes a two-electron reduction with calcium to form 2. EPR spectroscopy, X-ray crystallography, and theoretical studies show that the germanium center in 2 has two lone pairs of electrons and the radical is delocalized over the germanium-containing heterocycle. In contrast, the magnesium derivative of the germylidendiide dianion radical is unstable and undergoes dimerization with concurrent dearomatization to form the germylidenide anion complex [C6H3-2-{C(H)NAr}Ge-Mg-6-{C(H)-NAr}]2 ( 3). [ABSTRACT FROM AUTHOR]

Secondary phosphirane complexes isomerize above 100 °C to give the corresponding terminal phosphinidene complexes, which can be trapped by alkenes and alkynes. This reaction is a rare instance of the isomerization of a PIII derivative into a PI derivative. It appears to mimic the reductive elimination of alkanes from transition-alkylmetal hydrides. [ABSTRACT FROM AUTHOR]