n-methylmaleimide molecular weight (2026)

N-Methylmaleimide is a small but highly significant organic compound widely used in chemistry, pharmaceuticals, and materials science. As a derivative of maleimide, it features a reactive maleimide ring with a methyl group attached to nitrogen, giving it unique chemical properties. 

Understanding its molecular weight is essential for chemists and researchers because it directly impacts calculations for reactions, solution preparation, and compound formulation. Accurate knowledge of molecular weight ensures precise stoichiometry in laboratory experiments and industrial processes, making it a fundamental piece of information for anyone working with this compound. 

Beyond laboratory use, N-Methylmaleimide finds applications in polymer crosslinking, bioconjugation, and drug synthesis, where molecular weight plays a key role in determining reactivity and product outcomes. This article provides a comprehensive guide to the molecular weight of N-Methylmaleimide, exploring its calculation, chemical properties, applications, and practical importance in modern chemistry.

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Chemical Structure of N-Methylmaleimide

N-Methylmaleimide is an organic compound with the molecular formula C₅H₅NO₂, belonging to the class of maleimide derivatives. Its structure consists of a five-membered cyclic imide ring, known as the maleimide ring, with a double bond between two carbon atoms, making it highly reactive. The nitrogen atom in the ring is substituted with a methyl group, giving the compound its “N-Methyl” designation. This small modification significantly influences the chemical and physical properties of the molecule, including solubility, stability, and reactivity.

The compound is typically a solid at room temperature with a pale to white appearance and exhibits moderate solubility in organic solvents such as ethanol, acetone, and dimethylformamide (DMF). The maleimide ring’s double bond makes N-Methylmaleimide an excellent Michael acceptor, enabling its use in various chemical reactions, including click chemistry and polymer crosslinking.

Understanding the chemical structure is crucial because it directly relates to the compound’s molecular weight, reactivity, and applications. By knowing the positions of each atom and functional group, chemists can accurately calculate the molecular weight and predict the behavior of N-Methylmaleimide in both laboratory and industrial settings.

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Molecular Weight of N-Methylmaleimide

The molecular weight of a compound is the sum of the atomic weights of all the atoms in its molecular formula. For N-Methylmaleimide, the molecular formula is C₅H₅NO₂, which contains 5 carbon atoms, 5 hydrogen atoms, 1 nitrogen atom, and 2 oxygen atoms. Calculating the molecular weight involves adding the contributions of each atom:

• Carbon (C): 5 × 12.01 g/mol = 60.05 g/mol
  
• Hydrogen (H): 5 × 1.008 g/mol = 5.04 g/mol
  
• Nitrogen (N): 1 × 14.01 g/mol = 14.01 g/mol
  
• Oxygen (O): 2 × 16.00 g/mol = 32.00 g/mol
  

Adding these together: 60.05 + 5.04 + 14.01 + 32.00 = 111.10 g/mol.

This molecular weight is critical for practical laboratory calculations, such as determining the amount of compound needed to prepare solutions, performing stoichiometric reactions, or predicting yields in chemical synthesis. Moreover, knowing the precise molecular weight allows chemists to interpret experimental results accurately, especially when using techniques like mass spectrometry. It also provides insight into the compound’s behavior in different chemical environments and applications, including pharmaceuticals, polymer chemistry, and bioconjugation reactions.

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Methods to Determine Molecular Weight of N-Methylmaleimide

Determining the molecular weight of N-Methylmaleimide can be done through both experimental and computational approaches. Experimentally, mass spectrometry (MS) is one of the most accurate methods. MS ionizes the molecules and measures their mass-to-charge ratio, providing precise molecular weight data and confirming the compound’s identity. Another technique is nuclear magnetic resonance (NMR) spectroscopy, which, while primarily used to study structure, can indirectly support molecular weight verification by confirming the number of hydrogen and carbon atoms in the molecule. X-ray crystallography is also useful, especially for solid samples, as it gives detailed structural information that correlates with molecular mass.

On the computational side, chemists often rely on chemical databases such as PubChem, ChemSpider, or Sigma-Aldrich, which list molecular weights based on standardized atomic weights. Software tools for molecular modeling can also calculate the theoretical molecular weight and simulate molecular behavior in reactions.

Accurate determination of molecular weight is crucial for laboratory work, chemical synthesis, and industrial applications. It ensures correct stoichiometry, guides reaction planning, and validates experimental results. For N-Methylmaleimide, both experimental and computational methods complement each other, offering chemists reliable and precise molecular weight data.

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Physical and Chemical Properties Related to Molecular Weight

The molecular weight of N-Methylmaleimide (111.10 g/mol) directly influences its physical and chemical properties, which are critical for laboratory handling and practical applications. Physically, compounds with lower molecular weights, like N-Methylmaleimide, tend to have moderate melting points and are often solids at room temperature. This compound typically appears as a pale white solid, soluble in organic solvents such as ethanol, acetone, and dimethylformamide (DMF), but has limited solubility in water. The molecular weight also affects its vapor pressure and diffusion rate, which are relevant for handling in chemical labs.

Chemically, the presence of the reactive maleimide ring combined with the N-methyl substitution makes N-Methylmaleimide an effective Michael acceptor in organic reactions. The molecular weight ensures precise stoichiometric calculations when preparing reaction mixtures, as even small deviations can affect yield and efficiency. In polymer chemistry, the molecular weight influences the reactivity during crosslinking and bioconjugation processes. Additionally, MW affects the stability of the molecule under heat and light, guiding storage and safety precautions. Understanding these properties allows chemists to predict behavior, optimize reactions, and safely handle N-Methylmaleimide in diverse applications.

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Applications of N-Methylmaleimide

N-Methylmaleimide is a versatile compound with a range of applications in organic chemistry, pharmaceuticals, and materials science, largely due to its reactive maleimide ring and well-defined molecular weight. In organic synthesis, it is commonly used as a Michael acceptor, enabling reactions such as nucleophilic additions and click chemistry. These reactions are essential in forming complex molecules, making N-Methylmaleimide a valuable intermediate in chemical laboratories and research.

In the pharmaceutical industry, N-Methylmaleimide is utilized as a building block for drug synthesis and enzyme inhibitors. Its precise molecular weight allows chemists to calculate dosages and reaction stoichiometry accurately, ensuring consistent product quality. Moreover, it is often employed in bioconjugation techniques, where it reacts with thiol groups on proteins or peptides to create stable covalent bonds, crucial for developing therapeutic proteins and antibodies.

Material science is another important area of application. N-Methylmaleimide serves as a crosslinking agent in polymers, improving mechanical strength and thermal stability. Its molecular weight influences polymer chain length and reactivity, making it essential for designing specialized materials. Understanding both the molecular structure and weight of N-Methylmaleimide ensures its effective use across these fields, highlighting its significance in modern chemistry.

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Safety and Handling of N-Methylmaleimide

Although N-Methylmaleimide is widely used in chemistry and industry, it must be handled with care due to its reactivity and potential health hazards. The compound can cause skin and eye irritation, and inhalation of dust or vapors may lead to respiratory discomfort. Proper laboratory safety protocols are essential to minimize exposure and ensure safe handling.

The molecular weight of N-Methylmaleimide (111.10 g/mol) is relevant in safety considerations because it affects vapor pressure, diffusion rate, and the quantity used in reactions. Accurate weighing based on molecular weight ensures correct stoichiometry while avoiding excess, which could increase the risk of unwanted reactions or toxicity.

When storing N-Methylmaleimide, it should be kept in a cool, dry place, away from light and moisture, and in tightly sealed containers. Personal protective equipment (PPE) such as gloves, lab coats, and safety goggles is recommended. Work should be conducted in a well-ventilated fume hood to prevent inhalation of dust or vapors. In case of spills, proper chemical spill protocols must be followed to neutralize and contain the substance safely. By understanding its chemical properties and molecular weight, chemists can handle N-Methylmaleimide safely while maintaining accuracy in laboratory and industrial applications.

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Frequently Asked Questions 

1. What is the solubility of N-Methylmaleimide?
N-Methylmaleimide is moderately soluble in organic solvents such as ethanol, acetone, and dimethylformamide (DMF), but it has limited solubility in water. Solvent choice often depends on the type of reaction being performed.

2. How do you calculate the molecular weight of N-Methylmaleimide?
The molecular weight is calculated by summing the atomic weights of all atoms in its molecular formula (C₅H₅NO₂). Carbon: 5 × 12.01 = 60.05 g/mol, Hydrogen: 5 × 1.008 = 5.04 g/mol, Nitrogen: 14.01 g/mol, Oxygen: 2 × 16.00 = 32.00 g/mol. Total = 111.10 g/mol.

3. Why is molecular weight important in reactions?
Molecular weight is crucial for accurate stoichiometry, determining the amount of compound needed, predicting yields, and ensuring proper reaction conditions.

4. Can molecular weight vary with isotopes?
Yes, the standard molecular weight is an average based on isotopic distribution. Using isotopically labeled compounds can slightly alter the molecular weight.

5. What makes N-Methylmaleimide reactive?
Its reactive maleimide ring allows it to act as a Michael acceptor, enabling reactions with nucleophiles like thiols and amines, which is essential in organic synthesis, polymer chemistry, and bioconjugation.

These FAQs address common concerns, helping chemists and students use N-Methylmaleimide efficiently and safely.

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Conclusion

N-Methylmaleimide is a small but highly versatile compound with significant importance in chemistry, pharmaceuticals, and materials science. Its molecular weight of 111.10 g/mol, derived from the molecular formula C₅H₅NO₂, plays a crucial role in laboratory and industrial applications. Accurate knowledge of molecular weight ensures precise stoichiometry in chemical reactions, proper solution preparation, and predictable outcomes in synthesis and polymerization.

The compound’s structure a maleimide ring with an N-methyl substitution gives it unique chemical properties, including reactivity as a Michael acceptor. This reactivity underpins its diverse applications, from organic synthesis and drug development to polymer crosslinking and bioconjugation techniques. Additionally, understanding physical and chemical properties, such as solubility, melting point, and stability, allows chemists to optimize reactions and handle the compound safely.

Safety considerations are closely tied to molecular weight and chemical behavior. Proper storage, protective equipment, and controlled handling ensure that N-Methylmaleimide can be used effectively without risk. By combining knowledge of molecular weight, chemical structure, and practical applications, researchers and chemists can maximize the utility of N-Methylmaleimide, making it an indispensable tool in modern chemical science.

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