Borylene (BH₂) Lewis Structure

Borylene (BH₂) Lewis Structure: H₂B Lewis Structure, bent Geometry, sp2 Hybridization & Polarity

Borylene (BH₂) Key Facts

The Borylene (BH₂) Lewis structure is 2 B–H single bond; the central B has 3 electron domains (0 lone pairs), giving a trigonal planar electron-domain arrangement and a bent molecular geometry with a ≈119° bond angle. B is best described as sp2-hybridized, and Borylene (BH₂) is polar because the bent shape (and/or unequal terminal atoms) prevents cancellation of the bond dipoles.

Figure 1: Lewis Structure of Borylene (BH₂) (H₂B)

Chemical Formula	H₂B
CAS Number	12353-52-5
Total Valence Electrons	5
Lewis Structure	2 B–H single bond
Electron-Domain Geometry	trigonal planar
Molecular Geometry	bent
Hybridization Model	sp2 (central B)
Bond Angle	≈119°
Polarity	Polar molecule

PubChem and NIST list Borylene (BH₂) as H ₂B with CAS 12353-52-5; molecular weight ≈ None g/mol. View CAS 12353-52-5 dictionary details on Guidechem →

Applications of Borylene (BH₂) (CAS 12353-52-5)

As a hydride of B, Borylene (BH₂) is typically a strong reducing agent, a potential fuel component, or a precursor in inorganic and organometallic synthesis. Many pnictogen/sulfur hydrides are toxic, foul-smelling and pyrophoric or flammable, and are handled with appropriate ventilation and inert-atmosphere technique.

Reducing Agent Electron-rich hydrides reduce metal centers and functional groups in synthesis.

Precursor / Feedstock Source of B in the preparation of derivatives and doped materials.

Handling Often toxic/flammable/pyrophoric; inert atmosphere and active ventilation required.

Procurement Note "Borylene (BH₂)" is supplied in multiple commercial grades and package sizes. Specify purity, grade, moisture/impurity limits, package (cylinder, drum or bulk) and intended process, and use CAS 12353-52-5 as the primary identifier when screening suppliers; always confirm regional availability and safety documentation (SDS).

Step 1 - Valence Electrons & Central Atom

To draw the Borylene (BH₂) Lewis structure we first count the total valence electrons. H₂B contains 2×1 (H) + 3 (B); the net charge of 0 gives a total of 5 valence electrons to place.

The central atom is B. It is the least electronegative atom capable of forming multiple bonds and is surrounded by the more electronegative terminal atom(s); hydrogen, when present, always occupies a terminal position. Electronegativity considerations place the electron density toward the terminal atom(s).

Valence-electron count

Total valence electrons = 2×1 (H) + 3 (B) = 5 electrons.

Step 2 - Lewis Structure & Electron Distribution

Place B at the center and connect each surrounding atom with a single bond, complete octets on the terminal atoms, and place any remaining electrons on the central atom. The resulting electron distribution is: 2 B–H single bond; no lone pairs on B and one unpaired electron on B.

Counting bonding and nonbonding electrons around B therefore satisfies the octet/expanded-octet requirement for the drawn structure.

B–H ×2

B: 0 lone pairs, 2 bonding domains

2 bonding domains + 0 lone pairs = 3 electron domains

Octet Rule: Why B Has Eight Electrons B forms 2 bond(s) and retains 0 nonbonding electron(s), reaching an octet. No expanded octet is required for this second-row (or octet-satisfying) central atom.

Step 3 - VSEPR Theory & Geometry

VSEPR theory states that the 3 electron domains around B arrange to minimize mutual repulsion, giving an trigonal planar electron-domain geometry.

Because 0 of these domains are lone pair(s) — and lone pairs repel more strongly than bonding pairs — the observed molecular geometry is bent; the B bond angle is set to ≈119° rather than the ideal value for the electron-domain geometry.

Repulsion hierarchy

A useful VSEPR approximation is: lone pair–lone pair repulsion > lone pair–bonding pair repulsion > bonding pair–bonding pair repulsion. With 0 lone pair(s) on B, the lone-pair domains occupy positions that minimize overall repulsion while pushing the bonding domains (and therefore the bonded atoms) closer together.

Hybridization & Formal Charge

In the conventional localized-bond model, B uses sp2 hybrid orbitals to form the 3 equivalent electron-domain directions (2 bonding + 0 lone pair).

Formal-charge check

Formal charge on central B = V − N − ½B = 3 − 0 − ½×4 = 3. The nonzero formal charge is distributed by resonance / charge separation; the drawn structure is the lowest-energy contributor.

Modeling Note Modeling Note: sp2 is a compact model for the 3 electron-domain directions around B; full quantum-chemical treatments use molecular orbitals.

Is Borylene (BH₂) Polar or Nonpolar?

Borylene (BH₂) is polar. The bent shape prevents cancellation of the bond dipoles. The bond dipoles do not cancel, leaving a net molecular dipole, which strongly influences solvation behavior and intermolecular interactions.

Expert Quote — Structural Chemistry Perspective

The decisive structural fact is not simply that the individual bonds are polar; it is whether molecular symmetry allows their vector sum to vanish. In Borylene (BH₂) the bent arrangement prevents cancellation, so a permanent dipole remains.

Interpretation consistent with standard VSEPR / molecular-geometry references.

This polarity profile underpins its behavior as a solvent, reactant or process intermediate; when sourcing, specify grade and container compatibility.

Structural Comparison Table

Species	Formula	Central Atom	Electron Domains	Molecular Geometry	Polarity
Borylene (BH₂)	H₂B	B	3	bent	Polar
Boron trifluoride	BF₃	B	3	trigonal planar	Nonpolar
Boron trichloride	BCl₃	B	3	trigonal planar	Nonpolar
Diborane	B₂H₆	B	3	trigonal planar	Polar

Practice question Starting from the 5 valence electrons of H₂B, draw the Lewis structure and confirm the central B atom is sp2-hybridized with bent geometry. What happens to the bond angle if one terminal atom is replaced by a more electronegative substituent?

Looking for industrial bulk or specified-grade supplies of Borylene (BH₂) (CAS 12353-52-5)? Browse Supplier on Guidechem →

FAQs

Is H₂B polar or nonpolar?

Borylene (BH₂) is polar. Its bent geometry (and/or unequal terminal atoms) stops the bond dipoles from cancelling.

What is the Lewis structure of Borylene (BH₂)?

2 B–H single bond; no lone pairs on B and one unpaired electron on B. It uses all 5 valence electrons and the preferred structure carries a formal charge of 3 on the central atom.

What is the bond angle in Borylene (BH₂)?

The B angle is about ≈119°. Lone-pair repulsion compresses the angle from the ideal trigonal planar value.

What is the hybridization of B in Borylene (BH₂)?

The conventional model is sp2. Borylene (BH₂) has 3 electron domains around the central B.

What is the CAS number of Borylene (BH₂)?

The CAS number is 12353-52-5. PubChem and NIST identify this with H₂B; use it to locate suppliers and database records.

References

PubChem, Borylene (BH₂). Molecular formula, CAS number, molecular weight and chemical identity.
NIST Chemistry WebBook, SRD 69, Borylene (BH₂). Formula, CAS Registry Number and thermochemical / spectroscopic data.
IUPAC Gold Book. Definitions for "lone pair", "VSEPR", "hybridization" and "formal charge".
Atkins, P. & de Paula, J., Physical Chemistry. VSEPR, molecular geometry and dipole moments.
Guidechem supplier & dictionary records. Commercial sourcing and CAS-linked property pages for Borylene (BH₂) (CAS 12353-52-5).

Technical scope: Lewis structures, VSEPR and hybridization are model-based descriptions for chemical communication and structure prediction; actual molecular electronic structure is more accurately represented by molecular-orbital and quantum-chemical methods. Commercial grades vary substantially by supplier and intended use; CAS 12353-52-5 identifies the substance, not a universal purity specification.

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Borylene (BH₂) Lewis Structure

Borylene (BH₂) Lewis Structure