Boron

Boron:

Elemental crystalline Boron

Facts about Boron:

• Boron: Metalloid, with a high melting point and an empty P-orbital
• Fun fact about Boron: One of the key elements in Borax which is used to make slime.
• Chemical symbol: B
• Atomic number: 5

A crystal structure containing Boron:

A diborane illustrating the 'Banana bonding' of 2 borons bridged by 2 hydrogens

Facts about this structure:

• Formula: C₅₈ H₅₈ B₂ F₁₈ P₂
• Structure name: bis(μ-hydrido)-bis(2,4,6-tris(trifluoromethyl)phenyl)-bis(2-[bis(2,4,6-trimethylphenyl)phosphanyl]ethyl)-di-boron
• Fun fact about the structure: This compound is a mild reductant capable of making fomaldehyde from carbon monoxide
• CSD refcode: DOBDOQ (What's this?)
• Associated publication: Gerhard Erker, Jun Li, Constantin G. Daniliuc, Gerald Kehr, Angewandte Chemie, International Edition, 2019, 58, 6737, DOI: 10.1002/anie.201901634

More info:

Boron's chemistry is largely governed by it only having 3 electrons in its outer shell. As a result it tends to form 3 covalent bonds leaving one p-orbital unoccupied which can accept lone pairs of electrons. What is unusual in diboranes is that whilst a covalently bound hydrogen has no lone pairs, two molecules containing boron hydrogen bonds can share hydrogens in a form known colloquially as banana bonding due to its shape. This was first proposed by Longuet-Higgins while still an undergraduate chemist at Balliol college Oxford.

More info about the International Year of the Periodic Table (IYPT) in crystals project:

This project (#IYPTCrystals) is part of the International Year of the Periodic Table celebration (#IYPT2019), read more about the project here. You can follow us on social media using #IYPTCrystals and learn more about the wonders of crystals by following the CCDC on Twitter @ccdc_cambridge on Facebook ccdc.cambridge, on Instagram ccdc_cambridge or on YouTube CCDCCambridge.

If you want to find out more about some of the terms and concepts we have a Frequently Asked Questions Page.

A visualisation showing the structure containing Boron alongside other structures published in the same scientific article: