TY - JOUR A1 - Weiser, Jonas A1 - Cui, Jingjing A1 - Dewhurst, Rian D. A1 - Braunschweig, Holger A1 - Engels, Bernd A1 - Fantuzzi, Felipe T1 - Structure and bonding of proximity‐enforced main‐group dimers stabilized by a rigid naphthyridine diimine ligand JF - Journal of Computational Chemistry N2 - The development of ligands capable of effectively stabilizing highly reactive main‐group species has led to the experimental realization of a variety of systems with fascinating properties. In this work, we computationally investigate the electronic, structural, energetic, and bonding features of proximity‐enforced group 13–15 homodimers stabilized by a rigid expanded pincer ligand based on the 1,8‐naphthyridine (napy) core. We show that the redox‐active naphthyridine diimine (NDI) ligand enables a wide variety of structural motifs and element‐element interaction modes, the latter ranging from isolated, element‐centered lone pairs (e.g., E = Si, Ge) to cases where through‐space π bonds (E = Pb), element‐element multiple bonds (E = P, As) and biradical ground states (E = N) are observed. Our results hint at the feasibility of NDI‐E2 species as viable synthetic targets, highlighting the versatility and potential applications of napy‐based ligands in main‐group chemistry. KW - bond theory KW - computational chemistry KW - density functional calculations KW - main group elements KW - N ligands Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312586 VL - 44 IS - 3 SP - 456 EP - 467 ER - TY - INPR A1 - Wang, Sunewang R. A1 - Arrowsmith, Merle A1 - Böhnke, Julian A1 - Braunschweig, Holger A1 - Dellermann, Theresa A1 - Dewhurst, Rian D. A1 - Kelch, Hauke A1 - Krummenacher, Ivo A1 - Mattock, James D. A1 - Müssig, Jonas H. A1 - Thiess, Torsten A1 - Vargas, Alfredo A1 - Zhang, Jiji T1 - Engineering a Small HOMO-LUMO Gap and Intramolecular B–B Hydroarylation by Diborene/Anthracene Orbital Intercalation T2 - Angewandte Chemie, International Edition N2 - The diborene 1 was synthesized by reduction of a mixture of 1,2-di-9-anthryl-1,2-dibromodiborane(4) (6) and trimethylphosphine with potassium graphite. The X-ray structure of 1 shows the two anthryl rings to be parallel and their π(C\(_{14}\)) systems perpendicular to the diborene π(B=B) system. This twisted conformation allows for intercalation of the relatively high-lying π(B=B) orbital and the low-lying π* orbital of the anthryl moiety with no significant conjugation, resulting in a small HOMO-LUMO gap (HLG) and ultimately an unprecedented anthryl B–B bond hydroarylation. The HLG of 1 was estimated to be 1.57 eV from the onset of the long wavelength band in its UV–vis absorption spectrum (THF, λ\(_{onset}\) = 788 nm). The oxidation of 1 with elemental selenium afforded diboraselenirane 8 in quantitative yield. By oxidative abstraction of one phosphine ligand by another equivalent of elemental selenium, the B–B and C\(^1\)–H bonds of 8 were cleaved to give the cyclic 1,9-diboraanthracene 9. KW - boron KW - small HOMO-LUMO gap KW - diborenes KW - borylation KW - hydroarylation Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148126 N1 - This is the pre-peer reviewed version of the following article: S. R. Wang, M. Arrowsmith, J. Böhnke, H. Braunschweig, T. Dellermann, R. D. Dewhurst, H. Kelch, I. Krummenacher, J. D. Mattock, J. H. Müssig, T. Thiess, A. Vargas, J. Zhang, Angew. Chem. Int. Ed. 2017, 56, 8009., which has been published in final form at DOI: 10.1002/anie.201704063. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. VL - 56 IS - 27 ER - TY - INPR A1 - Stoy, Andreas A1 - Böhnke, Julian A1 - Jiménez-Halla, J. Oscar C. A1 - Dewhurst, Rian D. A1 - Thiess, Torsten A1 - Braunschweig, Holger T1 - CO\(_2\) Binding and Splitting by Boron–Boron Multiple Bonds T2 - Angewandte Chemie, International Edition N2 - CO\(_2\) is found to undergo room-temperature, ambient- pressure reactions with two species containing boron-boron multiple bonds, leading to incorporation of either one or two CO\(_2\) molecules. In one case, a thermally-unstable intermediate was structurally characterized, indicating the operation of an initial 2+2 cycloaddition mechanism in the reaction. KW - carbon dioxide KW - CO2 fixation KW - diborenes KW - diborynes KW - boron Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164265 N1 - This is the pre-peer reviewed version of the following article: A. Stoy, J. Böhnke, J. O. C. Jiménez‐Halla, R. D. Dewhurst, T. Thiess, H. Braunschweig, Angew. Chem. Int.Ed. 2018, 57,5947 –5951, which has been published in final form at DOI: 10.1002/anie.201802117. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. ER - TY - JOUR A1 - Schorr, Fabian A1 - Schopper, Nils A1 - Riensch, Nicolas A1 - Fantuzzi, Felipe A1 - Neder, Marco A1 - Dewhurst, Rian D. A1 - Thiess, Thorsten A1 - Brückner, Tobias A1 - Hammond, Kai A1 - Helten, Holger A1 - Finze, Maik A1 - Braunschweig, Holger T1 - Controlled Synthesis of Oligomers Containing Main-Chain B(sp\(^{2}\))-B(sp\(^{2}\)) Bonds JF - Chemistry—A European Journal N2 - A number of novel alkynyl-functionalized diarylbis(dimethylamino)diboranes(4) are prepared by salt metathesis, and the appended alkynyl groups are subjected to hydroboration. Their reactions with monohydroboranes lead to discrete boryl-appended diborane(4) species, while dihydroboranes induce their catenation to oligomeric species, the first known examples of well-characterized macromolecular species with B−B bonds. The oligomeric species were found to comprise up to ten repeat units and are soluble in common organic solvents. Some of the oligomeric species have good air stability and all were characterized by NMR and vibrational spectroscopy and size-exclusion chromatography techniques. KW - oligomerization KW - boron KW - catenation KW - diborane KW - hydroboration Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257274 VL - 27 IS - 64 ER - TY - JOUR A1 - Schmidt, Paul A1 - Fantuzzi, Felipe A1 - Klopf, Jonas A1 - Schröder, Niklas B. A1 - Dewhurst, Rian D. A1 - Braunschweig, Holger A1 - Engel, Volker A1 - Engels, Bernd T1 - Twisting versus delocalization in CAAC- and NHC-stabilized boron-based biradicals: the roles of sterics and electronics JF - Chemistry - A European Journal N2 - Twisted boron-based biradicals featuring unsaturated C\(_2\)R\(_2\) (R=Et, Me) bridges and stabilization by cyclic (alkyl)(amino)carbenes (CAACs) were recently prepared. These species show remarkable geometrical and electronic differences with respect to their unbridged counterparts. Herein, a thorough computational investigation on the origin of their distinct electrostructural properties is performed. It is shown that steric effects are mostly responsible for the preference for twisted over planar structures. The ground-state multiplicity of the twisted structure is modulated by the σ framework of the bridge, and different R groups lead to distinct multiplicities. In line with the experimental data, a planar structure driven by delocalization effects is observed as global minimum for R=H. The synthetic elusiveness of C\(_2\)R\(_2\)-bridged systems featuring N-heterocyclic carbenes (NHCs) was also investigated. These results could contribute to the engineering of novel main group biradicals. KW - chemistry KW - radicals KW - ab initio calculations KW - boron KW - carbene ligands KW - density functional calculations Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256636 VL - 27 IS - 16 ER - TY - JOUR A1 - Roy, Dipak Kumar A1 - Tröster, Tobias A1 - Fantuzzi, Felipe A1 - Dewhurst, Rian D. A1 - Lenczyk, Carsten A1 - Radacki, Krzysztof A1 - Pranckevicius, Conor A1 - Engels, Bernd A1 - Braunschweig, Holger T1 - Isolation and Reactivity of an Antiaromatic s‐Block Metal Compound JF - Angewandte Chemie International Edition N2 - The concepts of aromaticity and antiaromaticity have a long history, and countless demonstrations of these phenomena have been made with molecules based on elements from the p, d, and f blocks of the periodic table. In contrast, the limited oxidation‐state flexibility of the s‐block metals has long stood in the way of their participation in sophisticated π‐bonding arrangements, and truly antiaromatic systems containing s‐block metals are altogether absent or remain poorly defined. Using spectroscopic, structural, and computational techniques, we present herein the synthesis and authentication of a heterocyclic compound containing the alkaline earth metal beryllium that exhibits significant antiaromaticity, and detail its chemical reduction and Lewis‐base‐coordination chemistry. KW - antiaromaticity KW - aromaticity KW - beryllium KW - heterocycles KW - s-block metals Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224447 VL - 60 IS - 7 SP - 3812 EP - 3819 ER - TY - INPR A1 - Muessig, Jonas H. A1 - Thaler, Melanie A1 - Dewhurst, Rian D. A1 - Paprocki, Valerie A1 - Seufert, Jens A1 - Mattock, James D. A1 - Vargas, Alfredo A1 - Braunschweig, Holger T1 - Phosphine-Stabilized Diiododiborenes: Isolable Diborenes with Six Labile Bonds T2 - Angewandte Chemie, International Edition N2 - The lability of B=B, B-P and B-halide bonds is combined in the syntheses of the first diiododiborenes. In a series of reactivity tests, these diiododiborenes demonstrate cleavage of all six of their central bonds in different ways, leading to products of B=B hydrogenation and dihalogenation as well as halide exchange. KW - boron KW - low-valent main-group species KW - iodine KW - multiple bonding KW - 1,2-additions Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178608 N1 - This is the pre-peer reviewed version of the following article: J. H. Muessig, M. Thaler, R. D. Dewhurst, V. Paprocki, J. Seufert, J. D. Mattock, A. Vargas, H. Braunschweig, Angew. Chem. Int. Ed. 2019, 58, 4405, which has been published in final form at https://doi.org/10.1002/anie.201814230. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. ER - TY - JOUR A1 - Muessig, Jonas H. A1 - Lisinetskaya, Polina A1 - Dewhurst, Rian D. A1 - Bertermann, Rüdiger A1 - Thaler, Melanie A1 - Mitric, Roland A1 - Braunschweig, Holger T1 - Dibortetraiodid (B\(_2\)I\(_4\)) ist im Festkörper ein Polymer aus sp3‐hybridisiertem Bor JF - Angewandte Chemie N2 - Anhand der ersten Festkörperstrukturen von Dibortetraiodid (B\(_2\)I\(_4\)) wird gezeigt, dass dieses nicht, wie lange angenommen, analog zu den leichteren Dibortetrahalogeniden B\(_2\)F\(_4\), B\(_2\)Cl\(_4\) und B\(_2\)Br\(_4\) in allen Aggregatzuständen in Form diskreter Moleküle mit planaren, dreifach koordinierten Boratomen vorliegt. Röntgenstrukturanalysen, Festkörper‐NMR‐ und IR‐Messungen zeigen, dass B\(_2\)I\(_4\) im Festkörper in zwei polymeren Konformeren vorkommt, die tetraedrisch koordinierte Boratome enthalten. Anhand von DFT‐Rechnungen werden die IR‐Spektren in Lösung und im Festkörper simuliert und mit den experimentellen Daten verglichen. KW - Bor KW - Diboran KW - DFT-Rechnungen KW - Festkörperstrukturen KW - Halogene Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219653 VL - 132 IS - 14 ER - TY - JOUR A1 - Muessig, Jonas H. A1 - Lisinetskaya, Polina A1 - Dewhurst, Rian D. A1 - Bertermann, Rüdiger A1 - Thaler, Melanie A1 - Mitric, Roland A1 - Braunschweig, Holger T1 - Tetraiododiborane(4) (B\(_2\)I\(_4\)) is a Polymer based on sp\(^3\) Boron in the Solid State JF - Angewandte Chemie International Edition N2 - Herein we present the first solid‐state structures of tetraiododiborane(4) (B\(_2\)I\(_4\)), which was long believed to exist in all phases as discrete molecules with planar, tricoordinate boron atoms, like the lighter tetrahalodiboranes(4) B\(_2\)F\(_4\), B\(_2\)Cl\(_4\), and B\(_2\)Br\(_4\). Single‐crystal X‐ray diffraction, solid‐state NMR, and IR measurements indicate that B\(_2\)I\(_4\) in fact exists as two different polymeric forms in the solid state, both of which feature boron atoms in tetrahedral environments. DFT calculations are used to simulate the IR spectra of the solution and solid‐state structures, and these are compared with the experimental spectra. KW - boron tetraiodide KW - boron KW - density functional theory KW - diborane KW - halides KW - solid-state sturcture Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-209428 VL - 59 ER - TY - JOUR A1 - Lu, Wei A1 - Jayaraman, Arumugam A1 - Fantuzzi, Felipe A1 - Dewhurst, Rian D. A1 - Härterich, Marcel A1 - Dietz, Maximilian A1 - Hagspiel, Stephan A1 - Krummenbacher, Ivo A1 - Hammond, Kai A1 - Cui, Jingjing A1 - Braunschweig, Holger T1 - An unsymmetrical, cyclic diborene based on a chelating CAAC ligand and its small-molecule activation and rearrangement chemistry JF - Angewandte Chemie International Edition N2 - A one-pot synthesis of a CAAC-stabilized, unsymmetrical, cyclic diborene was achieved via consecutive two-electron reduction steps from an adduct of CAAC and B\(_2\)Br\(_4\)(SMe\(_2\))\(_2\). Theoretical studies revealed that this diborene has a considerably smaller HOMO–LUMO gap than those of reported NHC- and phosphine-supported diborenes. Complexation of the diborene with [AuCl(PCy\(_3\))] afforded two diborene–Au\(^I\) π complexes, while reaction with DurBH\(_2\), P\(_4\) and a terminal acetylene led to the cleavage of B−H, P−P, and C−C π bonds, respectively. Thermal rearrangement of the diborene gave an electron-rich cyclic alkylideneborane, which readily coordinated to Ag\(^I\) via its B=C double bond. KW - inorganic chemistry KW - thermal rearrangement KW - alkylideneborane KW - carbene KW - diborene Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256576 VL - 61 IS - 3 ER -