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Two coordinate boron cations are rare. Herein we report the synthesis of [RNSiMe2CH2]2BF (R = Dipp 3, 1-Ad 5) (Dipp = C6H3(iPr)2, Ad = C10H15) via the reaction of BF3 with the corresponding dilithiated diamides. Subsequent abstraction of fluoride provided the corresponding borinium salts, [(RNSiMe2CH2)2B][B(C6F5)4] (R = Dipp 6, 1-Ad 8). While the former was generated, the latter proved isolable and was crystallographically characterized. [ABSTRACT FROM AUTHOR]

para-Substitution reactions on C6F5 rings of Lewis acids have been exploited to achieve triply substituted derivatives. The reaction of B(C6F5)3 with P(SiMe3)3 ultimately affords the Lewis acid B(C6F4P(SiMe3)2)31. This species binds Lewis bases affording the adducts LB(C6F4P(SiMe3)2)3 (L = MeCN 2, OPEt33, PMe34, PBu35) and reacts with LiMe to give the salt [Li][MeB(C6F4P(SiMe3)2)3]·3THF 6. It also reacts with H2O to give (L)B(C6F4PH2)3 (L = H2O 7, MeCN 8). In an analogous fashion, [(C6F5)3PF][B(C6F5)4] was converted to [FP(C6F4P(SiMe3)2)3] [B(C6F5)4] 9 and subsequently to [(MeO)P(C6F4PH2)3][B(C6F5)4] 10. [ABSTRACT FROM AUTHOR]

Select triphenyl stannanes bearing either a formally sp2 or sp3 hybridized amine, viz 2-(pyC2H4)SnPh3 (2: py = pyridinyl), 4-(pyC2H4)SnPh3 (3), 2-(pzC2H4)SnPh3 (4: pz = pyrazyl), and Me2N(CH2)3SnPh3 (6), were prepared and characterized by NMR spectroscopy (119Sn, 13C, 1H), and additionally, in the case of 2, by single crystal X-ray diffraction. Bromination of 2 to yield 2-(pyC2H4)SnPhBr2 (8) was achieved in good yield. X-ray crystallographic analysis of 8 revealed two unique molecules with 5-coordinate Sn centers featuring Sn-N distances of 2.382 (5) and 2.363 (5) Å, respectively. The calculated structures of the non- and hypercoordinating C,N-stannanes (1–9) were in good agreement with available crystallographic data. The relative stabilities of hyper- and non-hypercoordinating conformers obtained from conformational sampling were determined by comparison with reference conformers and by natural bond orbital (NBO) energetic analyses. Reduction of 8 to the dihydride species, 2-(pyC2H4)SnPhH2 (9), and subsequent conversion to the polystannane, -[2-(pyC2H4)SnPh]n- (15), by transition metal-catalyzed dehydropolymerization was also achieved. Evidence for the decomposition of 15 into a redistributed distannoxane, {2-(pyC2H4)SnPh2}2O (16), was also observed. [ABSTRACT FROM AUTHOR]

Poly(3‐hexylthiophene) (P3HT) is a well‐studied conjugated polymer; however, the end‐group functionalization of these polymers is limited by fundamental synthetic challenges. Generally, end‐capping agents are used to terminate the Kumada catalyst transfer polycondensation (KCTP) to install functional end‐groups at the propagating chain end. In this work, it is shown that P3HT can be prepared with a novel SNAr‐active external initiator, followed by end capping to afford heterobifunctional end‐groups that exhibit orthogonal chemical reactivity. This orthogonal chemistry can be leveraged in sequential "click"‐type reactions to ultimately achieve the synthesis of triblock copolymers. More specifically, it is shown that the synthesis of a new pentafluorophenyl initiator allows one to append this readily functionalized group at the initiating end during P3HT synthesis. After reaching the desired degree of polymerization, an ethynyl group is incorporated at the polymer terminus using an end‐capping Grignard reagent. Critically, this heterobifunctional P3HT allows for both orthogonal para‐fluoro thiol reactions, a subset of nucleophilic aromatic substitution (SNAr), and copper‐catalyzed alkyne‐azide cycloadditions (CuAAC). The efficacy of this heterobifunctional polymer design is demonstrated by assessing sequential "click" reactions with different nonconjugated polymer blocks to either end of the P3HT polymer block. [ABSTRACT FROM AUTHOR]

The crystal structures of 16 boron subphthalocyanines (BsubPcs) with structurally diverse axial groups were analyzed and compared to elucidate the impact of the axial group on the intermolecular π–π interactions, axial‐group interactions, axial bond length and BsubPc bowl depth. π–π interactions between the isoindole units of adjacent BsubPc molecules most often involve concave–concave packing, whereas axial‐group interactions with adjacent BsubPc molecules tend to favour the convex side of the BsubPc bowl. Furthermore, axial groups that contain O and/or F atoms tend to have significant hydrogen‐bonding interactions, while axial groups containing arene site(s) can participate in π–π interactions with the BsubPc bowl, both of which can strongly influence the crystal packing. Bulky axial groups did tend to disrupt the π–π interactions and/or axial‐group interactions, preventing some of the close packing that is seen in BsubPcs with less bulky axial groups. The atomic radius of the heteroatom bonded to boron directly influences the axial bond length, whereas the axial group has minimal impact on the BsubPc bowl depth. Finally, the crystal growth method did not generally appear to have a significant impact on the solid‐state arrangement, with the exception of water occasionally being incorporated into crystal structures when hygroscopic solvents were used. These insights can help with the design and fine‐tuning of the solid‐state structures of BsubPcs as they continue to be developed as functional materials in organic electronics. [ABSTRACT FROM AUTHOR]

Correction for 'A chelated borinium cation' by Christopher Major et al., Dalton Trans., 2024, 53, 10075–10078, https://doi.org/10.1039/D4DT01242A. [ABSTRACT FROM AUTHOR]

para-Substitution reactions on C6F5 rings of Lewis acids have been exploited to achieve triply substituted derivatives. The reaction of B(C6F5)3 with P(SiMe3)3 ultimately affords the Lewis acid B(C6F4P(SiMe3)2)31. This species binds Lewis bases affording the adducts LB(C6F4P(SiMe3)2)3 (L = MeCN 2, OPEt33, PMe34, PBu35) and reacts with LiMe to give the salt [Li][MeB(C6F4P(SiMe3)2)3]·3THF 6. It also reacts with H2O to give (L)B(C6F4PH2)3 (L = H2O 7, MeCN 8). In an analogous fashion, [(C6F5)3PF][B(C6F5)4] was converted to [FP(C6F4P(SiMe3)2)3] [B(C6F5)4] 9 and subsequently to [(MeO)P(C6F4PH2)3][B(C6F5)4] 10. [ABSTRACT FROM AUTHOR]

The precise synthesis of subporphyrinoid hybrids with π-expanded topologies and unique material properties plays a promising role in the design of functional macrocycles. Easy, selective, and controllable routes to boron subphthalocyanine-subnaphthalocyanine hybrids, Bsub(Pc 3- p -Nc p )s, are desirable for this purpose yet synthetically challenging due to random mixtures of C s -, C 3 v -, and, in some cases, C 1 -symmetric compounds that form during traditional statistical mixed cyclotrimerizations. Herein, we addressed this issue by developing a sterically driven mixed cyclotrimerization with enhanced selectivity for the targeted C s -symmetric hybrid and complete suppression of sterically crowded macrocyclic byproducts. This process, coupled with a rationally designed precursor bearing bulky phenyl substituents, enabled the synthesis and characterization of bay-position phenylated Ph 2 -(R p ) 8 Bsub(Pc 2 -Nc 1 ) hybrids with halogens (R p = Cl or F) in their peripheral isoindole rings. Reaction selectivity ranged between 59 and 72% with remarkable yields, significantly higher than that of conventional mixed cyclotrimerizations. These findings were augmented by theoretical calculations on precursor Lewis basicity as guiding principles into hybrid macrocycle formation. Additionally, the incorporation of unfused phenyl groups and halogen atoms into the hybrid framework resulted in fine-tuned optical, structural, electronic, and electrochemical properties. This straightforward approach achieved improved selectivity and controlled narrowing of the product distribution, affording the efficient synthesis of structurally sophisticated Bsub(Pc 2 -Nc 1 ) hybrids. This then expands the library of 3-dimensional π-extended macrocycles for use in a range of applications, such as in optoelectronic devices with precisely tailored optical properties., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Co-published by University of Science and Technology of China and American Chemical Society.)

para -Substitution reactions on C 6 F 5 rings of Lewis acids have been exploited to achieve triply substituted derivatives. The reaction of B(C 6 F 5 ) 3 with P(SiMe 3 ) 3 ultimately affords the Lewis acid B(C 6 F 4 P(SiMe 3 ) 2 ) 3 1. This species binds Lewis bases affording the adducts LB(C 6 F 4 P(SiMe 3 ) 2 ) 3 (L = MeCN 2, OPEt 3 3, PMe 3 4, PBu 3 5) and reacts with LiMe to give the salt [Li][MeB(C 6 F 4 P(SiMe 3 ) 2 ) 3 ]·3THF 6. It also reacts with H 2 O to give (L)B(C 6 F 4 PH 2 ) 3 (L = H 2 O 7, MeCN 8). In an analogous fashion, [(C 6 F 5 ) 3 PF][B(C 6 F 5 ) 4 ] was converted to [FP(C 6 F 4 P(SiMe 3 ) 2 ) 3 ] [B(C 6 F 5 ) 4 ] 9 and subsequently to [(MeO)P(C 6 F 4 PH 2 ) 3 ][B(C 6 F 5 ) 4 ] 10.

Polar crystalline materials, a subset of the non-centrosymmetric materials, are highly sought after. Their symmetry properties make them pyroelectric and also piezoelectric and capable of second-harmonic generation (SHG). For SHG and piezoelectric applications, metal oxides are commonly used. The advantages of oxides are durability and hardness - downsides are the need for high-temperature synthesis/processing and often the need to include toxic metals. Organic polar crystals, on the other hand, can avoid toxic metals and can be amenable to solution-state processing. While the vast majority of polar organic molecules crystallize in non-polar space groups, we found that both 7-chloro-1,3,5-triazaadamantane, for short Cl-TAA, and also the related Br-TAA (but not I-TAA) form polar crystals in the space group R3m, easily obtained from dichloromethane solution. Measurements confirm piezoelectric and SHG properties for Cl-TAA and Br-TAA. When the two species are crystallized together, solid solutions form, suggesting that properties of future materials can be tuned continuously., (© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)