The replacement of C=C units by their isoelectronic and isosteric B=N (BN/CC isosterism) in π-conjugated organic compounds, as a strategy to produce novel organic-inorganic hybrid materials, has recently been successfully transferred polymers. This Concept provides an overview the recent advances this quickly evolving field, with focus on synthesis, photophysical electrochemical properties new polymers related oligomers, well possible future applications electronics optoelectronics.

Abstract The structural motif of porphyrin is relevant for many essential biological processes and has emerged as a versatile component functional materials. Here, we introduce thiophene-based porphyrinogen having electron-deficient boron atoms in all four meso -positions. Its fully π-conjugated backbone exhibits effectively concealed antiaromaticity, with locally confined aromaticity to the thiophene units. macrocycle readily binds fluoride ions, signaled by changes its photophysical...

The kinetics of the metal-free hydrogen transfer from amine–borane Me2NH·BH3 to aminoborane iPr2N═BH2, yielding iPr2NH·BH3 and cyclodiborazane [Me2N-BH2]2 via transient Me2N═BH2, have been investigated in detail, with further information derived isotopic labeling DFT computations. approach system toward equilibrium was monitored both directions by 11B{1H} NMR spectroscopy a range solvents at variable temperatures THF. Simulation resulting temporal–concentration data according simple...

Abstract Substitution of selected CC units in π‐conjugated organic frameworks by their isoelectronic and isosteric BN (BN/CC isosterism) has proven to be a successful concept for the development BN‐doped polycyclic aromatic hydrocarbons (PAHs) with intriguing properties functions. The first examples have just demonstrated applicability this approach polymer chemistry. Herein, we present synthesis comprehensive characterization poly(p‐phenylene iminoborane). This novel inorganic–organic...

Complexes of Group 4 metallocenes in the +3 oxidation state and amidoborane or phosphidoborane function as efficient precatalysts for dehydrocoupling/dehydrogenation amine-boranes, such Me(2) NH⋅BH(3). Such Ti(III) -amidoborane complexes are generated [Cp(2)Ti]-catalyzed amine-borane dehydrocoupling reactions, which diamagnetic M(II) M(IV) species have been previously postulated intermediates.

Despite the great potential of both π-conjugated organoboron polymers and BN-doped polycyclic aromatic hydrocarbons in organic optoelectronics, our knowledge conjugated with B-N bonds their main chain is currently scarce. Herein, first examples a new class organic-inorganic hybrid are presented, which consist alternating NBN para-phenylene units. Polycondensation bond formation provides facile access to soluble materials under mild conditions. The photophysical data for polymer molecular...

The significance of inorganic main-group polymers is demonstrated most clearly by the commercial relevance polysiloxanes (silicones). Organoboron-based materials such as π-conjugated organoborane and BN-doped polycyclic aromatic hydrocarbons are currently attracting considerable attention. Surprisingly, poly(iminoborane)s (PIBs; [BRNR']n ), that is, parent unsaturated BN polymers, which formally isoelectronic to polyacetylene, have not been convincingly characterized thus far. Herein, we...

Conjugated organoboranes have emerged as attractive hybrid materials for optoelectronic applications. Herein, a highly efficient, environmentally benign catalytic B-C bond formation method is presented that uses organosilicon compounds, dibromoboranes, and the metal-free organocatalyst Me3SiNTf2. This Si/B exchange approach has been successfully applied to synthesis of arylborane molecules 4a-c, oligomers 8a,b, polymers 8a',b'. Photophysical investigations, supported by TD-DFT calculations,...

Linear diborazanes R3N-BH2-NR2-BH3 (R = alkyl or H) are often implicated as key intermediates in the dehydrocoupling/dehydrogenation of amine-boranes to form oligo- and polyaminoboranes. Here we report detailed studies reactivity three related examples: Me3N-BH2-NMe2-BH3 (1), Me3N-BH2-NHMe-BH3 (2), MeNH2-BH2-NHMe-BH3 (3). The mechanisms thermal catalytic redistributions 1 were investigated depth using temporal-concentration studies, deuterium labeling, DFT calculations. results indicated...

Access to dithiophene-fused oxadiborepins and the first azadiborepins attained via a modular synthesis route are presented. The new compounds emit intense blue light, some of which demonstrate fluorescence quantum yields close unity. Cyclic voltammetry (CV) revealed electrochemically reversible one-electron reduction processes. weak aromatic character novel 1,2,7-azadiborepin ring is demonstrated with in-depth theoretical investigations using nucleus-independent chemical shift (NICS) scans...

The dehydrocoupling/dehydrogenation behavior of primary arylamine-borane adducts ArNH(2)⋅BH(3) (3 a-c; Ar = a: Ph, b: p-MeOC(6)H(4), c: p-CF(3)C(6)H(4)) has been studied in detail both solution at ambient temperature as well the solid state or elevated temperatures. presence a metal catalyst was found to be unnecessary for release H(2). From reactions 3 a,b concentrated solutions THF 22 °C over 24 h cyclotriborazanes (ArNH-BH(2))(3) (7 a,b) were isolated adducts, 7 a,b⋅THF, solvent-free a,...

The reaction of n-C8 H17 B[N(Me)SiMe3 ]2 (1) with BCl2 (2 a) yielded, instead a linear poly(iminoborane), the aminoborane B(Cl)N(Me)SiMe3 (4) and after cyclotrimerization borazine cyclo-(n-C8 BNMe)3 (6). Side reactions that result in formation were effectively suppressed if 1,3-bis(trimethylsilyl)-1,3,2-diazaborolidines 7 employed as co-monomers combination dichloro- or dibromoboranes 2 8, respectively. Silicon/boron exchange polycondensation led to oligo(iminoborane)s 11 a,b,ac,d....

Abstract The application of our newly developed B–C coupling method by catalytic Si/B exchange is demonstrated for the synthesis a series triarylboranes ( 1 ), monodisperse thienyl‐ and furylborane dimers 2 ) trimers 9 extended oligomers 3 polymers ′), as well mixed (oligo)thienyl‐/furylboranes. structures aa Tip , bb bbb Mes * determined X‐ray crystallography, reveal largely coplanar hetarene rings BR environments, which are most pronounced in species. Photophysical investigations,...

Abstract While certain inorganic main‐group polymers such as silicones (polysiloxanes) are ubiquitous in our everyday life, poly(iminoborane)s have been elusive for a long time. Incorporation of heterocyclic building blocks into their backbone has recently enabled access to the first derivatives this inorganic‐polymer class, approach effectively prevents undesired side‐reactions borazines. Information about microstructure these cyclolinear macromolecules, however, scarce. Herein, we present...

The combination of redox‐active ferrocene moieties, conju­gated B=N units, and p‐phenylene building blocks in linearly concate­nated architectural arrangements has been explored. Oligo‐ poly(ferrocenylene iminoborane)s have successfully prepared, whereby the latter case, formation linear polymers vs. dis­crete molecular macrocycles could be largely influenced by poly­merization conditions applied. In addition, a series well‐defined co‐oligomers composed ferrocenylene moieties bridged one or...

We report the synthesis of 5-bora-21,22-dioxaporphyrin 5 and its main-group d-block metal complexes 6 7, respectively. These macrocyclic boranes constitute first examples neutral porphyrins with boron in a meso-position that exhibit global aromaticity. This is evidenced by spectroscopic structural features as well calculated nucleus independent chemical shifts (NICS) anisotropic induced current densities (ACID). The boraporphyrins absorb light strongly red spectral region (Q bands) show...

1,2,3-Benzodiazaborines (DABs), isoelectronic to isoquinoline alkaloids, have attracted considerable interest due their unique reactivity and promising potential applications, including but not limited pH sensors, chiral probes or antibacterial agents. Although DABs with hemiboronic acid functionality been known since the 1960s were extensively studied then, a method convert borinic into borane moiety carbon-based substituents has remained elusive is of interdisciplinary interest. Herein, we...

Abstract Der isoelektronische und isostere Austausch ausgewählter CC‐ durch BN‐Einheiten in π‐konjugierten organischen Systemen (BN/CC‐Isosterie) hat sich als erfolgreiche Strategie zur Entwicklung BN‐dotierter polycyclischer aromatischer Kohlenwasserstoffe (PAKs) mit faszinierenden Eigenschaften Funktionen erwiesen. Unlängst haben erste Beispiele die Nützlichkeit dieses Konzepts der Polymerchemie gezeigt. Hier stellen wir Synthese Charakterisierung des ersten Poly(p‐phenyleniminoborans)...

Borazine-based inorganic–organic hybrid cyclomatrix microspheres with a mean diameter of about 900 nm have been obtained <italic>via</italic> novel silicon/boron exchange precipitation polycondensation approach.

An unprecedented poly(thiophene iminoborane)-a boron-nitrogen analogue of the well-established conjugated organic polymer vinylene)-is presented. The synthesis is achieved by selective Si/B exchange polycondensation a 2,5-diborylthiophene with 2,5-diaminothiophene derivative. For latter, facile synthetic strategy devised, which makes this versatile, strongly electron-releasing building block easily accessible. novel and series monodisperse thiophene iminoborane oligomers reveal systematic...