Ambient-Temperature Isolation of a Compound with a Boron-Boron Triple Bond

@article{Braunschweig2012AmbientTemperatureIO,
  title={Ambient-Temperature Isolation of a Compound with a Boron-Boron Triple Bond},
  author={Holger Braunschweig and Rian D. Dewhurst and Kai Hammond and Jan Mies and Krzysztof Radacki and Alfredo Vargas},
  journal={Science},
  year={2012},
  volume={336},
  pages={1420 - 1422}
}
B-B Bond Alkynes contain carbon-carbon triple bonds and represent a diverse class of organic compounds. In principle, valence rules suggest that the boron analog of an alkyne, with a B-B triple bond, ought to be accessible by appending a two-electron donor to each B atom. Braunschweig et al. (p. 1420; see the Perspective by Frenking and Holzmann) now present the synthesis, isolation, and crystallization of a solid, triple-bonded diboryne, with N-heterocyclic carbenes as the terminal… 
Prediction of Boron-Boron Triple-Bond Polymers Stabilized by Janus-Type Bis(N-heterocyclic) Carbenes.
TLDR
A class of polymeric compounds containing boron-boron triple bonds stabilized by N-heterocyclic biscarbenes is proposed and it is shown that the replacement of biscarbene with N2 or CO as spacers could change the bonding profile of the borons-borons units to a cumulene-like structure.
Reductive Insertion of Elemental Chalcogens into Boron-Boron Multiple Bonds.
TLDR
The demonstration of these six- and four-electron reductions lends support to the presence of three and two pairs of bonding electrons between the boron atoms of the diboryne and diborene, respectively, a fact that may be useful in future discussions on bond order.
A Boron-Boron Triple Bond
TLDR
A complex with a boron-boron triple bond expands the range of genuine triple bonds known to chemists and is reported on in this issue of Science.
Boronyl chemistry: the BO group as a new ligand in gas-phase clusters and synthetic compounds.
TLDR
An overview of research activities over the past few years that are relevant to the development of boronyl chemistry, in particular, in size-selected gaseous clusters containing BO is provided, and a unique concept of π and σ double conjugation is proposed for the first time to elucidate the structures and bonding in the double-chain nanoribbon boron diboronyL clusters.
Strongly Phosphorescent Transition Metal π-Complexes of Boron-Boron Triple Bonds.
TLDR
While the Cu diborene bond is dominated by electrostatic interactions, DFT studies show that the CuI π-complexes of diborynes reported herein exhibit enhanced metal d orbital contributions to HOMO and HOMo-1, which results in S1 and T1 having significant MLCT character, enabling strong spin-orbit coupling for highly efficient intersystem-crossing S1 → Tn and phosphorescence T1 → S0.
The boron–boron triple bond in NHC→BB←NHC
Quantum chemical calculations of the compound B2(NHCMe)2 and a thorough examination of the electronic structure with an energy decomposition analysis provide strong evidence for the appearance of
A two-coordinate boron cation featuring C-B+-C bonding.
TLDR
This diarylborinium ion possesses exceptional Lewis acidity, accepting a pair of electrons from CO2 to cause an unusual deoxygenation reaction and adopts a linear two-coordinate structure in both the solid state and in solution.
Metal-free binding and coupling of carbon monoxide at a boron-boron triple bond.
TLDR
In this work, CO was added to a boron-boron triple bond at room temperature and atmospheric pressure, resulting in a compound into which four equivalents of CO are incorporated: a flat, bicyclic, bis(boralactone).
A Stable Neutral Compound with an Aluminum-Aluminum Double Bond.
TLDR
X-ray crystallographic and spectroscopic analyses demonstrate that the dialuminum entity possesses trans-planar geometry and an Al-Al bond length of 2.3943(16) Å, which is the shortest distance reported for a molecular dialuminum species.
Triple B≡B bond: from a perfect Lewis structure to a dominant π-back-donation. The need for a reference point
Abstract Coordination of a B2 fragment by two σ-donor ligands could lead to complexes with a formal triple B≡B bond L→B≡B←L. Formation of L-B σ-bond leads to excess electrons around the B2 central
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 66 REFERENCES
Oxoboryl Complexes: Boron−Oxygen Triple Bonds Stabilized in the Coordination Sphere of Platinum
TLDR
Formation of the oxoboryl complex trans-[(Cy3P)2BrPt(B≡O)] (Cy being cyclohexyl) by means of reversible liberation of trimethylsilylbromide from the boron–bromine oxidative addition product of dibromo(trimethylsiloxy)borane and [Pt (PCy3)2] in room-temperature toluene solution is reported.
OCBBCO: a neutral molecule with some boron-boron triple bond character.
TLDR
Experimental and theoretical evidence is reported of a neutral OCBBCO molecule with some boron-boron triple bond character that was produced and unambiguously characterized by matrix isolation infrared spectroscopy.
Multiple boron-boron bonds in neutral molecules: an insight from the extended transition state method and the natural orbitals for chemical valence scheme.
TLDR
It is concluded that use of phosphorus ligands leads to strengthening of the B═B bond by 6.4 kcal/mol, and the orbital interaction term is more stabilizing; however, the effect is less pronounced compared to the drop in the Pauli repulsion term.
Molecules with all triple bonds: OCBBCO, N2BBN2, and [OBBBBO](2-).
TLDR
DFT calculations at the BP86/TZ2P level have been carried out for the compounds OCBBCO, N(2)BBN(2), and [OBBBBO](2-) and shows that the central boron-boron bonds are genuine triple bonds.
A stable, neutral diborene containing a B=B double bond.
TLDR
Compound 3 is the first structurally characterized neutral diborene and the nature of the BB double bond in 3 was delineated by DFT computations.
Boron Chemistry Lights the Way: Optical Properties of Molecular and Polymeric Systems.
Electrooptical and electronic materials are the subject of much research interest, whereby the focus has often been on electron-rich organic molecules. In the past years, new routes to
Synthesis and structure of the "dialuminyne" Na(2)[Ar'AlAlAr'] and Na(2)[(Ar''Al)3]: Al--Al bonding in Al2Na2 and Al3Na2 clusters.
TLDR
The synthesis and characterization of the first “dialuminyne” species Na2[Ar�’AlAlAlAr’] (3) and the “cyclotrialuminene” Na2 [(Al Ar’’)3] (4) are described, which are of key importance as the first metal of the p-block elements.
Pi-bonding and the lone pair effect in multiple bonds involving heavier main group elements: developments in the new millennium.
TLDR
The key unifying feature of almost all molecules discussed in this review is that they are generally stabilized by the use of bulky substituents which block associative or various decomposition pathways.
Comparison of B–B π-bonding in singly reduced and neutral diborane (4) derivatives: isolation and structure of [{Li(Et2O)2}{MeO(mes)BB(mes)OMe}]
A single-crystal X-ray diffraction study of [{Li(Et2O)2}-{MeO(mes)BB(mes)OMe}]1(mes = C6H2Me3-2,4,6) allows the first structural comparison between singly reduced and neutral diborane(4) species;
...
1
2
3
4
5
...