Heterocyclic diradicaloids with atom‐precise control over open‐shell nature are promising materials for organic electronics and spintronics. Herein, we disclose quinoidal π‐extension of a B/N‐heterocycle for generating B/N‐type organic diradicaloids. Two quinoidal π‐extended B/N‐doped polycyclic hydrocarbons that feature fusion of the B/N‐heterocycle motif with the antiaromatic s‐indacene or dicyclopenta[b,g]naphthalene core were synthesized. This quinoidal π‐extension and B/N‐heterocycle leads to their open‐shell electronic nature, which stands in contrast to the multiple‐resonance effect of conventional B/N‐type emitters. These B/N‐type diradicaloids have modulated (anti)aromaticity and enhanced diradical characters comparing with the all‐carbon analogues, as well as intriguing properties, such as magnetic activities, narrow energy gaps and highly red‐shifted absorptions. This study thus opens the new space for both of B/N‐doped polycyclic π‐systems and heterocyclic diradicaloids.

The mixed-anion GeS3O unit induces huge improvement in the optical anisotropy and NLO response from Sr2ZnGe2O7 oxide to Sr2MGe2S6O oxysulfides.

Tuning diradical character is an important topic for organic diradicaloids. Herein, we report the precise borylation enabling structural isomerism as an effective strategy to modulate diradical character and thereby properties of organic diradicaloids. We synthesized a new B‐containing polycyclic hydrocarbon that has the indeno[1,2‐b]fluorene π‐skeleton with the β‐carbons bonding to two boron atoms. Detailed theoretical and experimental results show that this bonding pattern leads to its distinctive electronic structures and properties in comparison to that of its isomeric molecule. This molecule has the efficient conjugation between boron atoms and π‐skeleton, resulting in downshifted LUMO and HOMO levels. Moreover, it exhibits smaller diradical character and thereby inhibited diradical properties, such as significantly blue‐shifted light absorption, larger energy bandgap and weak para‐magnetic resonance. Notably, this B‐containing polycyclic hydrocarbon possesses much stronger Lewis acidity and its Lewis acid‐base adducts display enhanced diradical character, demonstrating the positive effects of Lewis coordination on modulating diradical performance.

High-performance infrared nonlinear optical (IR NLO) materials are crucial devices in tunable IR solid-state lasers, and the functional-group cosubstitution strategy was selected to design and explore outstanding IR NLO crystals. For that reason, taking the famous AgGaSe 2 as the template, five new mercury-based IR NLO selenides, Li 2 HgMSe 4 and Na 2 Hg 3 M 2 Se 8 (M = Si, Ge, Sn), were successfully designed and synthesized through concurrently replacing the cation (Ag + ) and GaSe 4 unit with the alkali metal (Li + or Na + ) and anionic groups (HgSe 4 and MSe 4 ) to optimize crystal structures and performances. All of them exhibit extremely strong powder second-harmonic generation (SHG) responses (3.6−6.0 × commercial AgGaS 2 ) with the essential phase-matching behavior. Note that Li 2 HgSnSe 4 exhibits the largest SHG response (6.0 × AgGaS 2 ) among the known Hg-based chalcogenides without disorder structures, and its millimeter-level single-crystals were successfully grown by the Bridgman method. Theoretical analysis further illustrates that the different arrangement modes of HgSe 4 units offer considerable but distinguishing SHG contributions, such as Li 2 HgMSe 4 (53−55%) and Na 2 Hg 3 M 2 Se 8 (19−23%). This research result highlights the practicability of the functional group cosubstitution-oriented design strategy and Hg-based selenides could be viewed as the optimal system for future exploration of large SHG crystals.

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In recent years, exciting advances have been achieved in pursuing organic thin film transistors (OTFTs) with high mobility. Whereas, the economical infeasibility of Au source/drain (S/D) electrodes that are widely used in OTFTs hinders the further development of OTFTs in industry. In this study, the modified indium tin oxide (ITO) as S/D electrodes is adopted. The ITO is modified by HCl aqueous solutions, its surface work function is improved from 4.8 to 5.5 eV. By first‐principle calculations and experiments, the charge analysis shows that the Cl atom traps 0.475 electrons, which indicates that In–Cl dipoles are responsible for the increase of the surface work function, besides the HCl modification leads to In+‐Cl− bonds instead of In3+‐Cl− bonds on the ITO surface compared with the reported InCl3 modification. More encouragingly, In+‐Cl− surface is found to have higher Cl density, higher work function and higher conductivity. TIPS‐pentacene, with suitable HOMO level of 5.2 eV, is adopted as organic semiconductor, and the bar‐coating process is optimized to realize oriented films. OTFTs with maximum field‐effect mobility of 0.77 cm2 V−1 s−1 are achieved. The ITO electrodes modified by HCl can be promising in the industry.

A novel narrow-band blue light emission has been realized in Eu2+-activated Rb2HfSi3O9.