Formyl radical Lewis Structure

Formyl radical Lewis Structure: CHO Lewis Structure, bent Geometry, sp2 Hybridization & Polarity

Formyl radical Key Facts

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

Figure 1: Lewis Structure of Formyl radical (CHO)

Chemical Formula	CHO
CAS Number	2597-44-6
Total Valence Electrons	11
Lewis Structure	C–O double bond and C–H single bond
Electron-Domain Geometry	trigonal planar
Molecular Geometry	bent
Hybridization Model	sp2 (central C)
Bond Angle	≈119°
Polarity	Polar molecule

PubChem (CID 123370) and NIST list Formyl radical as CHO with CAS 2597-44-6; molecular weight ≈ 29.018 g/mol. View CAS 2597-44-6 dictionary details on Guidechem →

Applications of Formyl radical (CAS 2597-44-6)

This organic compound is used as a solvent, intermediate or specialty reagent in fine-chemical, pharmaceutical and materials synthesis; specify grade and impurity profile when sourcing.

Solvent / Reagent Medium for reactions, extraction or formulation.

Intermediate Building block for downstream derivatives.

Specialty Use Targeted role in pharma/fragrance/materials.

Procurement Note "Formyl radical" 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 2597-44-6 as the primary identifier when screening suppliers; always confirm regional availability and safety documentation (SDS).

Step 1 - Valence Electrons & Central Atom

To draw the Formyl radical Lewis structure we first count the total valence electrons. CHO contains 4 (C) + 1 (H) + 6 (O); the net charge of 0 gives a total of 11 valence electrons to place.

The central atom is C. 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 = 4 (C) + 1 (H) + 6 (O) = 11 electrons.

Step 2 - Lewis Structure & Electron Distribution

Place C 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: C–O double bond and C–H single bond; no lone pairs on C and one unpaired electron on C.

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

C=O C–H

C: 0 lone pairs, 2 bonding domains

2 bonding domains + 0 lone pairs = 3 electron domains

Octet Rule: Why C Has Eight Electrons C 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 C 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 C 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 C, 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, C uses sp2 hybrid orbitals to form the 3 equivalent electron-domain directions (2 bonding + 0 lone pair).

Formal-charge check

Formal charge on central C = V − N − ½B = 4 − 0 − ½×6 = 2. 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 C; full quantum-chemical treatments use molecular orbitals.

Is Formyl radical Polar or Nonpolar?

Formyl radical 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 Formyl radical 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
Formyl radical	CHO	C	3	bent	Polar
Carbon dioxide	CO₂	C	2	linear	Nonpolar
Carbon monoxide	CO	C	2	linear (diatomic)	Polar
Carbon disulfide	CS₂	C	2	linear	Nonpolar
Methane	CH₄	C	4	tetrahedral	Nonpolar
Ethane	C₂H₆	C	4	tetrahedral	Nonpolar

Practice question Starting from the 11 valence electrons of CHO, draw the Lewis structure and confirm the central C 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 Formyl radical (CAS 2597-44-6)? Browse Supplier on Guidechem →

FAQs

Is CHO polar or nonpolar?

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

What is the Lewis structure of Formyl radical?

C–O double bond and C–H single bond; no lone pairs on C and one unpaired electron on C. It uses all 11 valence electrons and the preferred structure carries a formal charge of 2 on the central atom.

What is the bond angle in Formyl radical?

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

What is the hybridization of C in Formyl radical?

The conventional model is sp2. Formyl radical has 3 electron domains around the central C.

What is the CAS number of Formyl radical?

The CAS number is 2597-44-6. PubChem (CID 123370) and NIST identify this with CHO; use it to locate suppliers and database records.

References

PubChem CID 123370, Formyl radical. Molecular formula, CAS number, molecular weight and chemical identity.
NIST Chemistry WebBook, SRD 69, Formyl radical. 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 Formyl radical (CAS 2597-44-6).

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 2597-44-6 identifies the substance, not a universal purity specification.

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Formyl radical Lewis Structure