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Strategic design for the construction of contiguous tetrasubstituted carbon centers represents a daunting challenge in synthetic organic chemistry. Herein, we report a combined experimental and computational investigation aimed at developing catalytic aerobic carbooxygenation, involving the intramolecular addition of tertiary radicals to geminally disubstituted alkenes, followed by aerobic oxygenation. This reaction provides a straightforward route to various α,α,β,β‐tetrasubstituted γ‐lactones, which can be readily transformed into hexasubstituted γ‐lactones through allylation/translactonization. Computational analysis reveals that the key mechanistic foundation for achieving the developed aerobic carbooxygenation involves the design of endothermic (energetically uphill) C−C bond formation followed by exothermic (energetically downhill) oxygenation. Furthermore, we highlight a unique fluorine‐induced stereoelectronic effect that stabilizes the endothermic stereodetermining transition state. [ABSTRACT FROM AUTHOR]

A silyliumylidene ion 2 stabilized by two σ‐donating Ni(0)‐ and Pd(0)‐fragments was successfully synthesized. Due to the σ‐donation of M→Si interactions, 2 presents a pyramidalized cationic silicon center with a localized lone pair. The additional coordination of basic Pd(0) fragment to the mono‐Ni(0)‐stabilized silyliumylidene 1 results in a higher HOMO level and an unchanged HOMO‐LUMO gap and thus, 2 remains highly reactive. Interestingly, the coordination mode at the Si center is closely related to the nature of M‐ligands. Indeed, the donor/donor‐stabilized silyliumylidene ion 2 has been transformed into a donor/acceptor‐stabilized ion 13, featuring a trigonal planar Si center with a vacant orbital, just via a ligand exchange reaction from PCy3/NHC toward PMe3. [ABSTRACT FROM AUTHOR]

Although second near‐infrared (NIR‐II, 1000–1500 nm) light has attracted considerable attention, especially for life sciences applications, the development of organic dyes with NIR‐II absorption remains a formidable challenge. Herein we report the design, synthesis, and electronic properties of 20π‐electron antiaromatic benziphthalocyanines (BPcs) that exhibit intense absorption bands in the NIR region. The strong, low‐energy absorption of the antiaromatic BPcs is attributed to electric‐dipole‐allowed HOMO‐LUMO transitions with narrow band gaps, enabled by the reduced structural symmetry of BPc compared with regular porphyrins and phthalocyanines. The combination of peripheral substituents and a central metal decreases the HOMO‐LUMO energy gaps, leading to the extension of the absorption bands into the NIR‐II region (reaching 1100 nm) under reductive conditions. [ABSTRACT FROM AUTHOR]

The treatment of the bulky Rind-based dibromosilanes, (Rind)2SiBr2 (2) [Rind = 1,1,7,7-tetra-R1-3,3,5,5-tetra-R2-s-hydrindacen-4-yl: EMind (a: R1 = Et, R2 = Me) and Eind (b: R1 = R2 = Et)], with two equivalents of tBuLi in Et2O at low temperatures resulted in the formation of blue solutions derived from the diarylsilylenes, (Rind)2Si: (3). Upon warming the solutions above −20 °C, the blue color gradually faded, accompanying the decomposition of 3 and yielding cyclic hydrosilanes (4) via intramolecular C–H bond insertion at the Si(II) center. The molecular structures of the bulky Eind-based 3b and 4b were confirmed by X-ray crystallography. Thus, at −20 °C, blue crystals were formed (Crystal-A), which were identified as mixed crystals of 3b and 4b. Additionally, colorless crystals of 4b as a singular component were isolated (Crystal-B), whose structure was also determined by an X-ray diffraction analysis. Although the isolation of 3 was difficult due to their thermally labile nature, their structural characteristics and electronic properties were discussed based on the experimental findings complemented by computational results. We also examined the hydrolysis of 3b to afford the silanol, (Eind)2SiH(OH) (5b). [ABSTRACT FROM AUTHOR]

The O2 splitting mediated by the bulky Rind-based diphosphenes resulted in the clean formation of the mixed-valent diphosphorus compounds, diphosphene oxides, with P2O moieties. Their structural features and electronic properties have been clearly characterized by experimental and theoretical methods. [ABSTRACT FROM AUTHOR]

A coordination network containing isolated pores without interconnecting channels is prepared from a tetrahedral ligand and copper(I) iodide. Despite the lack of accessibility, CO2 is selectively adsorbed into these pores at 298 K and then retained for more than one week while exposed to the atmosphere. The CO2 adsorption energy and diffusion mechanism throughout the network are simulated using Matlantis, which helps to rationalize the experimental results. CO2 enters the isolated voids through transient channels, termed "magic doors", which can momentarily appear within the structure. Once inside the voids, CO2 remains locked in limiting its escape. This mechanism is facilitated by the flexibility of organic ligands and the pivot motion of cluster units. In situ powder X‐ray diffraction revealed that the crystal structure change is negligible before and after CO2 capture, unlike gate‐opening coordination networks. The uncovered CO2 sorption and retention ability paves the way for the design of sorbents based on isolated voids. [ABSTRACT FROM AUTHOR]

The spontaneous orientation polarization (SOP) of 1,3,5,7-tetrakis(1-phenyl-1H-benzo[d]imidazol-2-yl)adamantane (TPBAD) and its photosensitivity were investigated and compared with those of 2,2′,2′′-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), a prototypical molecule exhibiting SOP. Despite the large difference in the molecular shapes of TPBAD (tetragonal) and TPBi (disc-shaped), their vacuum-deposited films exhibited similarly high SOPs of +74.7 and +77.2 mV nm−1, respectively. Due to the non-conjugated adamantane core, TPBAD had a wider optical band gap (4.22 eV) than TPBi (3.50 eV). This reduced the sensitivity of SOP in TPBAD films to light irradiation, and the decay time constant was 10 times longer than that of TPBi films. Variable angle spectroscopic ellipsometry and two-dimensional grazing-incidence wide-angle X-ray scattering revealed that TPBAD films are optically isotropic with a lower packing order than TPBi films, suggesting that the subtle directional selectivity of the TPBAD molecules in the amorphous film generates large SOP. [ABSTRACT FROM AUTHOR]

Allenes (>C=C=C<) are classified as cumulated dienes with a linear structure and an sp‐hybridized central carbon atom. We have synthesized and isolated a stable 2‐germapropadiene with bulky silyl substituents. The 2‐germapropadiene allene moiety adopts a linear structure both in the solid state and in solution. An X‐ray diffraction electron‐density‐distribution (EDD) analysis of this 2‐germapropadiene confirmed the linear C=Ge=C geometry with a formally sp‐hybridized germanium atom that bears two orthogonal C=Ge π‐bonds. Based on detailed structural and computational studies, we concluded that the linear geometry of the isolated 2‐germapropadiene most likely arises from the negative hyperconjugation of the silyl substituents at the terminal carbon atoms. The 2‐germapropadiene reacts rapidly with nucleophiles, indicating that the linearly oriented germanium atom is highly electrophilic. [ABSTRACT FROM AUTHOR]

Thermoelectric energy harvesters based on p- and n-type organic semiconductors are in high demand, while the air stability of n-type devices has long been a challenge. Here, we demonstrate that supramolecular salt-functionalized n-doped ladder-type conducting polymers exhibit excellent stability in the presence of dry air. [ABSTRACT FROM AUTHOR]

The synthesis of a series of ferrocenylvinylketenes as stable η4-[Fe(CO)3] complexes (3a–f) was successfully accomplished through the reaction of η2-[Fe(CO)4] complexes under mild carbonylation conditions. The reactivity of 3a–f under thermal conditions afforded the unexpected formation of a novel family of (μ2,η3-allyl-η5-oxapentadienyl)diiron pentacarbonyl complexes 5a–f proposed to be formed by a sequence metathesis-haptotropic rearrangement between the starting η4-vinylketene iron(0) complex 3 and a η4-vinylcarbene iron(0) complex trapped in situ after a reversible carbonylation process favored by the thermal conditions. An electron density distribution analysis (EDD) of 5e using high-resolution X-ray diffraction data in combination with the DFT framework was performed to understand the electronic communication between the two iron fragments. [ABSTRACT FROM AUTHOR]

A series of (E)-1,2-diaryldigermenes, (Eind)ArGe＝GeAr(Eind) [Ar = phenyl (2), thiophen-2-yl (3), 9,9-dimethyl-2-fluorenyl (4) and 2,2′-bithiophen-5-yl (5)], supported by the fused-ring bulky 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl (Eind) groups, have been obtained as yellow-orange to red crystalline solids by the reaction of 1,2-dibromodigermene, (Eind)BrGe＝GeBr(Eind) (1), with ArLi. In the crystals of 2–5, the digermene cores show a flexible nature adopting a trans-bent geometry with the trans-bent angles () between the Ge–Ge vector and the CEind–Ge–CAr plane of 34.04(12)° (2), 38.3(3)° and 38.8(3)° (3), 33.69(12)° (4) and 39.30(13)° (5). In the UV-vis spectra, strong π–π* absorptions have been observed with an absorption maximum at 451 nm (ε = 1.3 × 104) (2), 455 nm (ε = 9.7 × 103) (3), 480 nm (ε = 1.3 × 104) (4) and 497 nm (ε = 1.4 × 104) (5), retaining the Ge＝Ge double bond in solution. The absorption data and DFT calculations provide evidence for the intrinsic π-conjugation between the Ge＝Ge chromophore and aromatic rings involving the narrowing of the HOMO–LUMO gaps (ΔE) with the extension of the carbon π-electron systems. [ABSTRACT FROM AUTHOR]

Molecular design strategy of the π‐electron core is of importance to enhance the organic semiconducting performance. In this study, diphenanthro[1,2‐b:2′,1′‐d]thiophene (DPT) as a new zigzag‐shaped sulfur‐bridged π‐electron core and its phenyl‐substituted derivative (Ph–DPT) exhibiting unique orbital configurations are reported. The DPT derivatives are readily synthesized through a versatile synthetic scheme in five steps from the commercially available dibenzothiophene. Their single‐crystal structural analyses and band calculations revealed that both DPTs form typical herringbone packing structures, which are favorable for 2D charge carrier transport, along with small effective masses. Single‐crystal‐based field‐effect transistors (FETs) of both DPT and Ph–DPT exhibit p‐type behaviors and charge‐carrier mobility up to 5.5 cm2 V–1 s–1. These results provide information that can broaden the molecular design approaches toward high‐performance organic semiconductors. [ABSTRACT FROM AUTHOR]

We present the experimental visualization of the valence-electron-density distribution in benzene and its kinetically stabilized heavier-element analogues, i.e., 1,2-disilabenzene and 1,2-digermabenzene. The valence-electron-density-distribution (EDD) analysis on the 1,2-disila- and 1,2-digermabenzenes revealed that these contain incompletely delocalized π electrons on their cyclic conjugation systems, making them less aromatic compared to benzene. Based on the results of this EDD analysis in combination with anisotropy of the current-induced density (ACID) calculations, considerable contributions from the characteristic resonance structures of 1,2-disila- and 1,2-digermabenzenes with cleaved E＝E bonds can be expected. [ABSTRACT FROM AUTHOR]