MOLINATE

Molinate is a selective systemic thiocarbamate herbicide whose defining commercial role is grass control in flooded rice.
Unlike many pesticide active ingredients supplied as crystalline solids, Molinate is a clear organic liquid, and its combination of moderate water solubility with appreciable volatility strongly influences formulation, field retention, storage and environmental containment.
Its present procurement context includes technical active ingredient and formulated material for legally authorised markets, together with analytical and research grades used in residue, environmental, resistance and toxicological work.

CHEMICAL IDENTITY AND COMMON NAMES

Molinate is the accepted common name for S-ethyl azepane-1-carbothioate, a synthetic monothiocarbamate containing a seven-membered azepane ring and an S-ethyl carbothioate group.
The molecule is neutral under ordinary environmental conditions, has no stereogenic centre and is not supplied as a mixture of geometric or optical isomers.
The older term hexamethyleneimine in several systematic names describes the same saturated azepane ring and does not indicate a different active ingredient.

Molinat, molinato and molinaat are established language variants of the same pesticide common name.
Commercial trade names are not chemical synonyms and are intentionally excluded from the identity list.

Synonyms and Common Names: Molinate, S-ethyl azepane-1-carbothioate, S-ethyl hexahydro-1H-azepine-1-carbothioate, S-ethyl hexahydroazepine-1-carbothioate, S-ethyl perhydroazepine-1-carbothioate, S-ethyl perhydroazepine-1-thiocarboxylate, S-ethyl N,N-hexamethylenethiocarbamate, S-ethyl-N,N-hexamethylene-thiocarbamate, 1H-azepine-1-carbothioic acid, hexahydro-, S-ethyl ester, azepane-1-carbothioic acid S-ethyl ester, S-ethyl 1-azepanecarbothioate, S-ethyl 1-perhydroazepinecarbothioate, ethyl 1-hexamethyleneiminecarbothioate, ethyl 1-hexamethyleneiminecarbothiolate, Molinat, Molinato, Molinaat

TECHNICAL IDENTIFICATION

CAS Number: 2212-67-1
EC / EINECS Number: 218-661-0
CLP Index Number: 613-051-00-4
CIPAC Number: 235
Pesticide Chemical Code: 041402
Molecular Formula: C9H17NOS
Molar Mass: 187.30 g/mol
IUPAC Name: S-ethyl azepane-1-carbothioate
Chemical Class: Thiocarbamate herbicide
Canonical SMILES: CCSC(=O)N1CCCCCC1
InChIKey: DEDOPGXGGQYYMW-UHFFFAOYSA-N
Isomerism: None

MOLECULAR DESIGN AND HERBICIDAL ACTION

Molinate belongs to herbicide Group 15, with the legacy classification K3.N for thiocarbamates.
It interferes with the synthesis of very-long-chain fatty acids required for membrane lipids, cuticular components and normal expansion of newly developing shoot tissue.
Susceptible seedlings consequently show suppressed shoot elongation, stunting and failure of normal emergence rather than the rapid leaf scorching associated with contact herbicides.

Uptake occurs through roots and basal shoot tissues, after which the active ingredient and its metabolites move within the plant.
Oxidative metabolism produces Molinate sulfoxide as well as hydroxy and oxo derivatives of the azepane ring, and sulfoxide formation is part of the metabolic activation characteristic of thiocarbamate herbicides.
The chemistry therefore involves both the parent molecule delivered by the formulation and biologically generated oxidation products.

Selectivity between rice and barnyardgrass is not explained by one barrier alone.
Barnyardgrass absorbs more Molinate than rice, while the two plants differ in translocation direction, metabolite pattern and conjugation chemistry.
These combined differences allow useful suppression of susceptible Echinochloa seedlings while established rice tolerates an authorised treatment programme.

Resistance has been recorded in Echinochloa crus-galli and Echinochloa oryzicola.
Where Molinate remains registered, resistance management uses rotation or combination with effective non-Group 15 modes of action, cultural weed suppression, clean seed, field scouting and control of surviving plants.

PHYSICAL AND CHEMICAL PROFILE

Physical State: Liquid
Appearance: Clear, colourless to pale yellow liquid
Odour: Aromatic, sometimes described as spicy
Freezing Point: -25 °C
Boiling Point: 278 °C
Density: 1.063 g/mL at 20 °C
Water Solubility: 1.1 g/L at 20 °C and pH 7
Organic Solvent Solubility: Miscible with methanol, acetone, ethyl acetate and hexane
Log Kow: 2.86 at pH 7 and 20 °C
Dissociation: Non-ionising; pKa is not applicable
Vapour Pressure: 0.5 Pa at 20 °C
Henry's Law Constant: 0.687 Pa·m3/mol at 25 °C
Ultraviolet Absorption: Maximum near 200 nm, with no significant absorption above 290 nm
Explosive Properties: Not explosive
Oxidising Properties: Not oxidising
Technical Active Purity: Historically specified at a minimum of 950 g/kg

The water-solubility value is high enough for meaningful distribution through shallow floodwater, yet the log Kow still permits interaction with organic matter, plant surfaces and formulation solvents.
Because Molinate does not ionise in the normal pH range, pH changes do not create charged forms that would fundamentally alter this partitioning behaviour.

The vapour pressure is modest compared with a conventional solvent but high for a pesticide active ingredient.
Its Henry's law constant shows that transfer from water to air is commercially and environmentally important, particularly over the large exposed surface of a flooded paddy.

WHY WATER MANAGEMENT MATTERS

Floodwater serves as a distribution phase for Molinate, carrying dissolved active ingredient to emerging weed shoots and roots.
The same water surface also creates a route for volatilisation, while drainage can move dissolved residues beyond the treated field.
Performance and environmental containment are therefore closely tied to maintaining the water regime specified by the authorised product label.

Molinate is only slowly hydrolysed in neutral water, with an aqueous hydrolysis half-life near 365 days at pH 7 and 20 °C.
Direct photolysis is also limited because the molecule absorbs little sunlight above 290 nm.
The much faster decline observed in paddy water consequently reflects volatilisation, sorption, biological transformation and transfer to soil or sediment rather than rapid hydrolytic destruction of the molecule.

A representative organic-carbon adsorption coefficient of about 190 mL/g places Molinate in the moderately mobile range.
Flooded-soil degradation has a representative half-life near 28 days, while field dissipation can be faster, with a representative half-life of 12.5 days.
In water-sediment systems, the overall half-life is about 61 days even though the water-phase concentration can fall within several days as the active ingredient redistributes or dissipates.

The measured bioconcentration factor of about 72 indicates limited bioaccumulation compared with strongly hydrophobic pesticides.
This does not remove the aquatic hazard, because Molinate is very toxic to aquatic life and can produce long-lasting effects.
Containment of irrigation water, spray drift, vapour, spills and equipment washings is therefore central to responsible handling.

PRODUCTION, FORMULATION AND COMMERCIAL FORM

An established synthesis prepares ethyl thiochloroformate from phosgene and ethanethiol and then couples this reactive thiocarbonyl intermediate with azepane, also known as hexamethyleneimine.
Base control neutralises the acid formed during carbamoylation and supports completion of the N-C(O)-S linkage.
The crude liquid is washed, phase-separated and purified, commonly with vacuum finishing, before assay and impurity control.

Industrial manufacture requires closed equipment because the route involves highly toxic phosgene, odorous ethanethiol, reactive acyl intermediates and corrosive off-gases.
Containment, off-gas scrubbing, temperature control and rigorous residual-reactant analysis are defining process requirements rather than optional refinements.

Technical Molinate is a liquid active ingredient traditionally supplied at approximately 95% minimum purity for formulation.
Its principal agricultural forms have been emulsifiable concentrates and granules.
Analytical supply forms include neat high-purity material and prepared calibration solutions intended for instrumental analysis.

In an emulsifiable concentrate, solvent selection must maintain a homogeneous liquid while the surfactant package forms a stable dispersion after dilution into water.
Density, viscosity, flash behaviour, low-temperature stability, emulsion stability and container compatibility are therefore evaluated together.
Volatile loss during formulation and filling is controlled through closed transfer and prompt sealing.

Granular formulations distribute the liquid active ingredient on an inert carrier suited to placement in flooded fields.
Uniform active loading, carrier absorption capacity, particle-size distribution, attrition resistance, dust generation, release into water and package stability determine whether the granule delivers reproducibly.
Granules change placement and operator exposure characteristics, but they do not change Molinate's intrinsic aquatic toxicity or volatility after release.

APPLICATIONS AND INDUSTRIES

Rice herbicide systems

Molinate's principal established agricultural function is selective control of germinating and young grass weeds in paddy rice, especially barnyardgrass and closely related Echinochloa species.
Root and basal-shoot uptake suits flooded production systems in which the active ingredient is distributed through shallow water and reaches the elongating tissues of young weeds.
Its value is associated with early growth suppression, not with rapid desiccation of mature foliage.

Crop stage, weed stage, water depth, soil texture, percolation and the period for which floodwater is retained all affect biological performance.
Only registered formulations, crops, timings, rates and water-management directions apply to agricultural use in a particular market.

Resistance and mode-of-action research

Molinate is used as a defined Group 15 thiocarbamate in studies of very-long-chain fatty-acid inhibition, metabolic activation and differential crop selectivity.
Comparative work with susceptible and resistant Echinochloa populations can examine uptake, oxidative metabolism, conjugation, cross-resistance and the contribution of non-target-site resistance.
Research-grade identity and a well-characterised impurity profile are especially important when small metabolic differences are being measured.

Residue and environmental analysis

Water authorities, agricultural laboratories and environmental monitoring programmes analyse Molinate in paddy water, drainage, groundwater, soil, sediment and crop matrices.
Its neutral, moderately lipophilic and volatile character makes gas chromatography with mass-selective detection particularly suitable for trace analysis.
Sample extraction, headspace control, storage temperature and evaporation steps require attention so that volatilisation does not bias recovery.

Analytical programmes may also include Molinate sulfoxide, carboxymolinate and matrix-specific transformation products when the monitoring objective extends beyond the parent active ingredient.
Isotopically labelled internal standards and matrix-matched calibration can improve quantification where recovery and matrix effects are demanding.

Toxicology and metabolism research

Molinate is a specialist research substance in investigations of thiocarbamate oxidation, cholinesterase effects, aldehyde dehydrogenase inhibition and male reproductive toxicity.
The parent compound and its sulfoxide or sulfone metabolites must be distinguished because metabolic oxidation changes enzyme-inhibition behaviour.
High-purity material, controlled storage and complete analytical characterisation are necessary for reproducible mechanistic work.

Analytical reference materials

Neat standards and accurately prepared solutions support identity confirmation, instrument calibration, method validation, recovery studies and residue surveillance.
For this use, certified purity, concentration uncertainty, metrological traceability, homogeneity, stability, solvent identity and expiry information matter more than bulk formulation properties.
Agricultural technical material is not interchangeable with a certified analytical reference material.

REGULATORY POSITION AND PROCUREMENT CONTEXT

Molinate has a fragmented regulatory history rather than a single worldwide status.
United States pesticide registrations were cancelled in 2008, and European Union active-substance approval expired on 31 July 2014.
Limited authorised rice uses remain in some national markets, while other jurisdictions permit only research, analytical or waste-management activities involving the substance.

Agricultural sale and use proceed under the pesticide registration, approved label, residue limits, import rules and water-protection controls of the destination market.
Technical active ingredient, end-use formulation and analytical reference material are legally and technically distinct supply categories.
The destination, intended use and required regulatory documentation should therefore be defined at the start of procurement.

GRADE AND FORMULATION SELECTION

Technical active ingredient is selected for registered formulation manufacture and is evaluated primarily by Molinate assay, related organic impurities, water, acidity, residual solvents, density, colour and non-volatile residue.
The historical 950 g/kg minimum active-substance purity is a useful technical benchmark for this supply form.
A chromatographic impurity profile is more informative than assay alone when the material will enter toxicological, metabolism or sensitive formulation work.

Emulsifiable-concentrate selection adds active content, solvent composition, density, viscosity, flash characteristics, emulsifiability, emulsion stability, persistent foam, low-temperature stability and package compatibility to the purchasing specification.
Granule selection instead emphasises active-content uniformity, carrier identity, moisture, particle-size distribution, attrition, dust, flow and release behaviour in water.

Research and analytical grades require a different hierarchy of controls.
Identity by orthogonal techniques, high chemical purity, traceability, uncertainty, solution concentration, solvent identity and stability data are central, while field-formulation attributes are irrelevant.
The grade designation should always match whether the material is intended for formulation, regulated residue analysis, environmental monitoring or mechanistic research.

QUALITY CONTROL AND DOCUMENTATION

Gas chromatography with flame-ionisation detection is well suited to routine assay of technical Molinate, while gas chromatography-mass spectrometry provides strong identity and impurity confirmation.
Infrared spectroscopy and nuclear magnetic resonance add orthogonal structural evidence for high-purity or reference material.
Water content, acidity, density and non-volatile residue reveal process carryover or deterioration that a single assay result can miss.

For emulsifiable concentrates, a useful release programme examines dilution behaviour in waters of defined hardness as well as active content and physical stability.
For granules, representative sampling is critical because local differences in carrier loading can be hidden by a composite assay.
For calibration solutions, gravimetric preparation records, solvent blank quality, ampoule or vial integrity and stability assessment protect concentration accuracy.

A Certificate of Analysis records batch-specific test results.
A Safety Data Sheet communicates classification, exposure controls, transport and emergency measures for the supplied grade and package.
A Technical Data Sheet describes the commercial form, relevant properties, intended technical context and storage conditions.

SAFETY, EXPOSURE AND ENVIRONMENTAL PROTECTION

Molinate is harmful if swallowed or inhaled and can cause an allergic skin reaction.
It is classified as suspected of causing cancer, suspected of damaging fertility and capable of causing organ damage through prolonged or repeated exposure.
It is also very toxic to aquatic life with long-lasting effects.

CLP Hazard Statements: H302, H317, H332, H351, H361f, H373, H400, H410
Representative Acute Oral LD50: 483 mg/kg in rats
Representative Acute Dermal LD50: Greater than 4,350 mg/kg in rats
Representative Acute Inhalation LC50: 1.39 mg/L in rats

Molinate has cholinesterase-inhibiting and neurotoxic potential, while oxidative metabolites can inhibit aldehyde dehydrogenase.
Animal data identify the male reproductive system as an important target of repeated exposure.
Possible poisoning signs include nausea, vomiting, diarrhoea, headache, dizziness, weakness, respiratory difficulty and neurological effects.

Closed transfer, local exhaust ventilation and restricted access reduce inhalation and skin exposure during bulk handling.
Chemical splash goggles, suitable chemical-resistant gloves, protective clothing and footwear are used for routine operations.
Respiratory protection selected for organic vapour and aerosol hazards is required when engineering controls cannot maintain controlled exposure, and emergency response to a concentrated release requires a higher level of respiratory and chemical protection.

Molinate must not enter drains, surface water, irrigation channels or soil outside the controlled work area.
Firefighting water and contaminated absorbents are contained for hazardous-waste disposal because dilution does not remove the aquatic hazard.
Heating can produce carbon oxides, nitrogen oxides and sulfur oxides.

FIRST AID

Inhalation: Move the exposed person to fresh air, maintain a clear airway and obtain immediate medical attention if exposure is significant or symptoms occur.
Skin Contact: Remove contaminated clothing and wash the skin thoroughly with soap and water.
Eye Contact: Rinse cautiously with clean water for at least 15 minutes, remove contact lenses when easy to do and obtain medical attention for persistent irritation.
Ingestion: Rinse the mouth, do not induce vomiting and obtain immediate medical advice.
Note to Physicians: Treatment is symptomatic and supportive, with attention to respiratory status, neurological findings and cholinesterase-related effects.

HANDLING, STORAGE AND SPILL CONTROL

Handle Molinate in closed or well-contained equipment with effective vapour control.
Avoid breathing vapour or mist and prevent all unnecessary contact with skin, eyes and clothing.
Do not eat, drink or smoke in handling areas, and wash exposed skin before breaks and after work.

Store the material tightly closed in a cool, dry, well-ventilated and secured pesticide or toxic-chemical area.
Protect containers from direct sunlight, heat and physical damage.
Segregate Molinate from strong oxidising agents, peroxides, acids and acid halides, and use compatible pumps, seals, linings and gaskets.

For a spill, isolate the area, remove ignition and exposure sources where this can be done safely, stop the leak and protect drains.
Recover free liquid into a compatible labelled container, then collect the remainder with a compatible non-combustible absorbent selected for thiocarbamate liquids.
Contaminated soil, absorbent, wash liquid and protective equipment are managed as hazardous pesticide waste.

PACKAGING AND PROCUREMENT CONSIDERATIONS

Technical and formulation material is packaged in tightly sealed, chemically compatible containers such as suitable high-density polyethylene or internally lined metal packaging.
Closures, headspace, seal integrity and vapour permeability deserve particular attention because gradual evaporative loss can change active content and create occupational exposure.
Analytical quantities are commonly protected in sealed glass vials or ampoules, while calibration solutions require solvent-compatible closures and breakage-resistant secondary packaging.

A complete Molinate enquiry identifies the intended use, required grade, active content or certified purity, formulation type, pack size, destination market, analytical documentation and delivery schedule.
Agricultural orders also require the applicable registration and label pathway, whereas analytical orders require the target matrix, concentration, solvent and traceability level.
These details align the package, documentation and quality-control programme with the actual technical purpose of the material.

For Molinate grade selection, formulation parameters, analytical documentation, packaging and supply planning, contact Ataman Kimya at +90 216 577 10 10 or info@atamankimya.com.