chemistry

Sulfentrazone

Sulfentrazone is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sulfentrazone rather than just read about it. In short: Sulfentrazone is the ISO common name for an organic compound used as a broad-spectrum herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase.

Key takeaways

Sulfentrazone belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sulfentrazone to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sulfentrazone from memory before moving on to harder problems.

Reference excerpt

Sulfentrazone is the ISO common name for an organic compound used as a broad-spectrum herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase. It was first marketed in the US in 1997 by FMC Corporation with the brand name Authority.

History In 1985, scientists at FMC Corporation filed patents on a new class of herbicides containing a triazolinone ring. Sulfentrazone was subsequently developed for market under the code number F6285, with first sales in 1991 and achieving registration in the US in 1997, branded Authority. Other compounds now in the triazolinone class include amicarbazone and carfentrazone.

Mechanism of action The effects visible on whole plants are chlorosis and desiccation caused by the inhibition of the enzyme protoporphyrinogen oxidase, which leads to an accumulation of protoporphyrin IX in the plant cells. This is a potent photosensitizer which activates oxygen, leading to lipid peroxidation. Both light and oxygen are required for this process to kill the plant.

Usage In the United States, the Environmental Protection Agency (EPA) is responsible for regulating pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the Food Quality Protection Act (FQPA) and the Pesticide Registration Improvement Act (PRIA). A pesticide can only be used legally according to the directions on the label that is included at the time of the sale of the pesticide. The purpose of the label is "to provide clear directions for effective product performance while minimizing risks to human health and the environment". A label is a legally binding document that mandates how the pesticide can and must be used and failure to follow the label as written when using the pesticide is a federal offence. The label includes use for removal of sedges and newly emerged broadleaf weeds including purple and yellow nutsedge, Kyllinga, plantain, clover, spurge, woodsorrel, knotweed, chickweed, curly dock, wild onion, and wild garlic. It is also effective on many grasses including Poa annua, Poa trivialis, creeping bentgrass, fine & tall fescue, perennial ryegrass, Kentucky & rough bluegrass, bahiagrass, Bermuda grass, buffalograss, carpetgrass, centipedegrass, kikuyugrass, seashore paspalum, St. Augustine grass, and zoysiagrass. Sulfentrazone can be used both pre- and post-emergence and is rapidly metabolised by soybean at the methyl group of the triazolinone ring, which confers a level of safety to that crop. The estimated annual use of sulfentrazone in US agriculture is mapped by the US Geological Service and shows that in 2017, the latest date for which figures are available, approximately 3,800,000 pounds (1,700,000 kg) were applied — mainly in soybean. The compound is not registered for use in the European Union, although another triazolinone, carfentrazone-ethyl, is available there. Sulfentrazone also has uses outside agriculture: it controls vegetation on roadside verges and railroads. The active ingredient has been sold alone or in combination with other herbicides under a large number of brand names including Dismiss, Solitaire and Spartan. Suppliers and brand names in the United States are listed in the National Pesticide Information Retrieval System.

Human safety The LD50 of sulfentrazone is more than 2800 mg/kg (rats, oral), which means that it is of low toxicity by oral ingestion. The US Code of Federal Regulations records the maximum residue tolerances in various food products.

References

External links Sulfentrazone in the Pesticide Properties DataBase (PPDB)

Illustrations

Worked examples

Example 1 — a first encounter with Sulfentrazone

Start with the simplest possible case. Write down what Sulfentrazone claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sulfentrazone before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sulfentrazone ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sulfentrazone

In research: Sulfentrazone appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sulfentrazone in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sulfentrazone is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chloroarenes, Difluoromethyl compounds, Group 14 herbicides, so understanding it makes those chapters shorter.
In everyday life: Look for Sulfentrazone outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Sulfentrazone in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sulfentrazone means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sulfentrazone out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sulfentrazone in simple terms?

Sulfentrazone is the ISO common name for an organic compound used as a broad-spectrum herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase.

Why does Sulfentrazone matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sulfentrazone?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sulfentrazone.