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Cyanamide / Diazomethane Polarity

Cyanamide / Diazomethane (CAS 420-04-2 / 334-88-3) is polar. CH2N2 has a calculated dipole of about 4.14 D, which follows from its linear carbon centre Snyder polarity index Not conventionally assigned; XlogP3-AA -0.57 (Crippen calculated, RDKit). Jacobson6 MIN READOctober 8, 2026
Reviewed by: Guidechem Scientific Editorial Board
Standards: IUPAC & PubChem Guidelines  |  Updated: 2026

Is CH2N2 (Cyanamide / Diazomethane) Polar or Nonpolar? Molecular Polarity & Structure Analysis

Cyanamide / Diazomethane Polarity Cover
CH2N2 (Cyanamide / Diazomethane) is a polar molecule. The primary amine (–NH₂) and nitrile (–C≡N) gives the molecule a locally polar region that is not mirrored elsewhere in the structure, so the bond dipoles do not cancel. The calibrated dipole moment is μ ≈ 4.14 D — large for a molecule of this size. With 50 Ų of topological polar surface area and 3 hydrogen-bond sites, it is expected to interact strongly with polar and protic media. Catalogue note: this listing names more than one substance on a single line (Cyanamide / Diazomethane). The structure resolved here is the one registered under CAS 420-04-2 — cyanamide, so the polarity statement above applies to that substance alone and not to the alternative(s) named beside it.

2D Lewis Structure of Cyanamide / Diazomethane (CH2N2)
Figure 1: 2D Lewis Structure (CH 2N 2; linear carbon centre)

Polarity Parameters of CH2N2

CAS Registry Number 420-04-2 / 334-88-3
Molecular Formula CH2N2
Molecular Weight 42.040 g/mol
Valence Electrons 16
Lewis Structure Guide View CH2N2 Lewis Structure Guide
Dipole Moment (μ) ≈ 4.14 D (calculated: GFN2-xTB//MMFF94, gas phase, single conformer, calibrated against a 60-molecule benchmark; typical residual ±0.3 D)
Dielectric Constant (εr) ≈ 1.05927 (calculated dilute-gas estimate, Debye equation, 298 K, 1 atm)
Snyder Polarity Index (P′) Not conventionally assigned
XlogP3-AA -0.57 (Crippen calculated, RDKit) (computed descriptor)
Note: Snyder P′ is a chromatographic solvent scale developed for conventional liquid solvents; the dipole moment is a calculated value (GFN2-xTB single point on an MMFF94 geometry, gas phase, single conformer, calibrated against a 60-molecule benchmark), not a measurement; treat it as good to about ±0.3 D; the relative permittivity is a dilute-gas estimate obtained from the Debye equation at 298 K and 1 atm, not a liquid dielectric constant; XlogP is a calculated partition descriptor, not a direct measure of solvent polarity.

1. Molecular Polarity Analysis of Cyanamide / Diazomethane: Geometry & Dipole Vector

To determine whether Cyanamide / Diazomethane (CH2N2) is polar or nonpolar, the decisive question is whether the bond dipoles of the molecule cancel once its three-dimensional shape is taken into account. Cyanamide / Diazomethane is a nitrile, built from primary amine (–NH₂) and nitrile (–C≡N). As set out in the CH2N2 Lewis Structure Guide, CH2N2 has 3 heavy atoms. For cyanamide (USEPA/OPP Pesticide Code: 014002) ACTIVE products with label matches..

The bond polarities follow from electronegativity. The largest differences in the structure are C–N (ΔEN ≈ 0.49), so electron density is pulled toward nitrogen. In three dimensions, the carbon centre is linear (180°) with sp hybridization. As a result, the calibrated dipole moment is μ ≈ 4.14 D. Treated as a dilute ideal gas at 298 K and 1 atm, the Debye equation converts that dipole into a relative permittivity of about 1.05927 — a number very close to unity, which is exactly what a gas-phase value should look like.

For formulation and process work, the useful consequences are these: the calculated topological polar surface area is 49.8 Ų, 1 hydrogen-bond donor and 2 hydrogen-bond acceptors, the Crippen calculated partition coefficient is logP ≈ -0.57 and the calculated molar refractivity is 9.80 cm³ mol⁻¹. A negative logP indicates a net preference for the aqueous phase over octanol, which is what one expects when polar and ionisable groups dominate a small molecule. PubChem’s curated experimental record adds: Cyanamide / Diazomethane is 78 % at 59 °F (NIOSH, 2024).

Valence-electron check: Counting valence electrons from the formula: nitrogen contributes 2 × 5 = 10, carbon contributes 1 × 4 = 4 and hydrogen contributes 2 × 1 = 2, giving 10 + 4 + 2 = 16 valence electrons.

2. Cyanamide / Diazomethane application: For cyanamide (USEPA/OPP Pesticide Code: 014002) ACTIVE products with…

PubChem’s use and manufacturing record describes Cyanamide / Diazomethane as follows: For cyanamide (USEPA/OPP Pesticide Code: 014002) ACTIVE products with label matches. These applications are what make the polarity question practical — solvent choice, extraction recovery, cleaning and formulation all turn on how strongly the molecule interacts with polar phases.

The measured physical behaviour recorded for this substance is consistent with that picture. Solubility: 78 % at 59 °F (NIOSH, 2024). Physical Description: Cyanamide appears as colorless deliquescent crystals.. Density: 1.28 (NIOSH, 2024) - Denser than water;. Melting Point: 113 °F (NIOSH, 2024). These are database values and should be read with the conditions (temperature, purity, pressure) that the source states.

Treated as a dilute gas, the calculated relative permittivity is about 1.05927 at 298 K and 1 atm. That figure is close to unity because a gas is mostly empty space: it is a useful consistency check on the dipole, but it is not the number to use when sizing a liquid process, where condensed-phase permittivity and specific interactions dominate.

Structurally the reactivity sits in primary amine (–NH₂) and nitrile (–C≡N). That functional inventory, together with the large dipole, is what predicts the solubility and adsorption behaviour: polar groups give the molecule a handle on polar solvents and on polar surfaces, while the hydrocarbon portion resists them.

PubChem’s GHS record for this substance lists H301: Toxic if swallowed [Danger Acute toxicity, oral] and H311: Toxic in contact with skin [Danger Acute toxicity, dermal]. Those classifications, not the polarity of the molecule, normally determine packaging, labelling, ventilation and transport requirements.

Industrial Sourcing & Compliance Insight: For Cyanamide / Diazomethane, the commercially relevant specification is assay, grade, water content and the impurity profile declared on the certificate of analysis, together with the packaging and transport class required for the destination market. Because the molecule carries hydrogen-bond donors, it is sensitive to residual moisture and to the choice of drying agent. Request the certificate of analysis with the enquiry rather than after it: for a substance handled at industrial scale, the declared impurity profile usually decides whether a lot is usable more often than the nominal purity does.

Recommended Analytical Quality-Control Strategy

  • Identity confirmation: FTIR or Raman against a reference spectrum, supported by GC–MS or LC–MS where the compound is amenable; this is the fastest way to catch a mis-labelled lot.
  • Assay / purity: GC-FID or GC-MS for volatile material, HPLC with a validated detector for non-volatile or thermally labile material; state the basis (area %, assay on dried substance, or titrimetric) on the certificate of analysis.
  • Water content: Karl Fischer titration is the default for a substance whose polarity and hydrogen-bonding capacity make it hygroscopic; moisture is the single most common cause of out-of-specification lots.
  • Related substances: a gradient HPLC or GC method capable of resolving the synthesis by-products and the isomeric impurities typical of this structure.
  • Acid–base / ionisable content: a validated acid–base titration or potentiometric determination, since the ionisable group controls both the assay and the behaviour in use.

In short, specify Cyanamide / Diazomethane by assay, water content, impurity profile, packaging and transport class, and state the intended application on the enquiry. The polarity analysis above explains behaviour in use; it does not replace a specification.

3. Polarity Comparison: CH2N2 and Related Industrial Fluids

The comparison below places CH2N2 next to structurally related substances from the same catalogue. Dipole moments come from one consistent protocol (GFN2-xTB//MMFF94, gas phase, single conformer) and are quoted only where that protocol has been validated; where it has not, the cell says so instead of giving a number. Permittivities are dilute-gas estimates from the Debye equation, logP values are Crippen calculations, and the solubility column is a qualitative inference from the calculated descriptors rather than a measurement.

Compound Dipole Moment Approx. Gas εr log P / XlogP Water Solubility Behavior Industrial Sourcing
CH2N2 ≈4.14 D (calc.) ≈1.0593 logP ≈ -0.57 78 % at 59 °F (NIOSH, 2024) See supply listing
C2H3N ≈3.92 D (lit.) ≈1.0389 logP ≈ 0.53 Moderate (inferred from logP) See supply listing
C2H7N ≈1.23 D (calc.) ≈1.0070 logP ≈ 0 Moderate to high (inferred from logP < 0) See supply listing
CH6N2 ≈0.19–2.17 D (conformers) ≈1.0017 logP ≈ -0.92 High (polar, H-bonding; inferred) See supply listing
CIN non-zero, not quoted — logP ≈ 0.90 Moderate (inferred from logP) See supply listing

The spread across this table is the point: composition alone does not set the polarity verdict. CH2N2 sits where it does because of the balance between its polar functional groups and the asymmetry of its shape, and any of the neighbouring entries can be the better choice once the temperature, the phase and the required polarity window are fixed.

4. Expert R&D Commentary

Expert Chemical Commentary
“A dipole of about 4.14 D puts CH 2N 2 in the large range, and it comes directly from the geometry: the carbon centre is linear (180°) with sp hybridization. A calculated logP of -0.57 tells you where it will partition. The curated experimental record is consistent: 78 % at 59 °F (NIOSH, 2024).”

5. Regulatory, Safety & Sustainability Trends

Regulatory status is specific to the substance and to the jurisdiction, and it changes. For CAS 420-04-2 / 334-88-3 the authoritative public sources are the ECHA registered-substance database for the EU, and the OSHA and NIOSH tables for occupational exposure in the United States.

PubChem’s GHS record for this substance lists H301: Toxic if swallowed [Danger Acute toxicity, oral] and H311: Toxic in contact with skin [Danger Acute toxicity, dermal]. These statements are the ones that must appear on the label and in section 2 of the safety data sheet; they, rather than the polarity of the molecule, drive classification, packaging group and transport documentation.

No occupational exposure limit for this substance is quoted in this article, because none was present in the database record used here. Publishing a limit that is not on the record would be worse than publishing none: obtain the applicable value from the OSHA Z-table, the NIOSH pocket guide or the equivalent national instrument before designing the ventilation or monitoring programme.

From a compliance and sustainability standpoint, the polarity of CH2N2 is a means rather than an end. It determines which solvent can replace another, how completely the substance can be recovered from a stream, and how much energy the separation will cost — so it belongs in the process justification, while the hazard classification and the exposure limits belong in the safety case.

6. Guidechem's Procurement Tips: What to Specify for Cyanamide / Diazomethane

A purchase enquiry for Cyanamide / Diazomethane (CAS 420-04-2 / 334-88-3) should state the grade, assay basis, permitted impurity limits, water content, packaging, and the transport and regulatory status required for the destination market. Where the substance is used as a reagent or intermediate, the impurity profile usually matters more than the nominal percentage.

Because polarity governs phase behaviour, it also governs recovery: a large molecule is easier to strip from a non-polar stream and harder to dry than a non-polar one, and vice versa. Confirm the Guidechem supply listing for current availability and compare lots on the certificate of analysis rather than on the label alone.

Industrial Engineering & Sourcing Specifications

Looking for commercial bulk supplies or technical documentation for Cyanamide / Diazomethane (CAS 420-04-2 / 334-88-3)?

Frequently Asked Questions (FAQs)

Is Cyanamide / Diazomethane polar or nonpolar?

Cyanamide / Diazomethane is polar. The bond dipoles do not cancel, giving a calculated dipole of about 4.14 D.

What is the dipole moment of Cyanamide / Diazomethane?

The calculated gas-phase dipole is approximately 4.14 D, obtained as a GFN2-xTB single point on an MMFF94-optimised geometry and then calibrated. Against 60 molecules with published gas-phase dipoles the calibrated protocol has a median residual of about 0.12 D and a 90th percentile near 0.3 D; it returns exactly zero whenever symmetry requires zero.

How does the molecular geometry decide the answer?

The carbon centre is linear (180°) with sp hybridization. The vector sum of the bond dipoles is what remains once the shape is fixed, so geometry — not the mere presence of polar bonds — is the deciding factor.

What is the dielectric constant of Cyanamide / Diazomethane?

The dilute-gas estimate from the Debye equation at 298 K and 1 atm is about 1.05927. That is a gas-phase number and is close to unity by construction; it is not a liquid dielectric constant, and no liquid value is quoted here unless it appears in the cited database record.

Does Cyanamide / Diazomethane have a Snyder polarity index?

Not in routine tabulations. Snyder P′ was developed for conventional liquid chromatographic solvents, and this substance is outside the scope of that scale. Dipole moment, calculated logP and hydrogen-bond counts are the descriptors used here instead.

How does Cyanamide / Diazomethane behave toward water?

The curated database record states: 78 % at 59 °F (NIOSH, 2024). The calculated logP of -0.57 is consistent with that behaviour.

What should be checked before buying Cyanamide / Diazomethane?

Grade, assay basis, water content, the declared impurity profile, packaging and the transport classification, plus the regulatory status required for the destination market. PubChem’s GHS record for this substance lists H301: Toxic if swallowed [Danger Acute toxicity, oral] and H311: Toxic in contact with skin [Danger Acute toxicity, dermal].

References & Academic Databases

  1. PubChem Compound Summary: Cyanamide / Diazomethane, CAS RN 420-04-2 / 334-88-3, CID 9864. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov
  2. ECHA Substance Information: Cyanamide / Diazomethane, CAS 420-04-2 / 334-88-3 — REACH registration status, harmonised classification and regulatory context. European Chemicals Agency.
  3. NIST Chemistry WebBook / CCCBDB: experimental geometry, vibrational data and dipole-moment compilations for Cyanamide / Diazomethane. National Institute of Standards and Technology.
  4. CRC Handbook of Chemistry and Physics, 92nd ed. (Haynes, W. M., ed.), CRC Press, 2011 — electronegativity, dielectric constant and dipole-moment tables.
  5. Nelson, R. D.; Lide, D. R.; Maryott, A. A.: Selected Values of Electric Dipole Moments for Molecules in the Gas Phase, NSRDS-NBS 10, National Bureau of Standards, 1967.
  6. Snyder, L. R.: solvent-polarity classification and the P′ scale for liquid chromatographic solvents. The P′ scale is defined only for conventional liquid solvents and is not assigned to substances outside that scope.
  7. Bannwarth, C.; Ehlert, S.; Grimme, S.: GFN2-xTB — an accurate and broadly parametrised self-consistent tight-binding quantum chemical method with multipole electrostatics and density-dependent dispersion contributions. J. Chem. Theory Comput. 2019, 15 (3), 1652–1671.
  8. RDKit / Halgren, T. A.: MMFF94 force field for geometry generation (J. Comput. Chem. 1996, 17, 490–519) and the RDKit cheminformatics toolkit used for the Crippen logP, TPSA and hydrogen-bond descriptors quoted here.
Technical note: Dipole moment, relative permittivity, Snyder P′ and calculated logP are not interchangeable descriptors. For CH 2N 2 the dipole is a calculated value (GFN2-xTB single point on an MMFF94-optimised geometry, gas phase, single conformer, calibrated against a linear fit to 60 published gas-phase dipoles). On that benchmark the median residual is about 0.12 D and the 90th percentile is near 0.3 D, so treat the number as a guide rather than a measurement. The relative permittivity quoted is a dilute-gas estimate from the Debye equation at 298 K and 1 atm and must not be read as a liquid dielectric constant. Procurement and process decisions should rest on application-specific specifications — grade, assay, water content and impurity profile — supported by measured property data, rather than on a single polarity number.
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