Zinc dimethyldithiocarbamate is a

coordination complex A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as '' ligands'' or complexing agents. M ...

of zinc with

dimethyldithiocarbamate Dimethyldithiocarbamate is the organosulfur anion with the formula (CH3)2NCS2−. It is one of the simplest organic dithiocarbamate. Uses It is a component of various pesticides and rubber chemicals in the form of its salts sodium dimethyldithio ...

. It is a pale yellow solid that is used as a

fungicide Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality ...

, the

sulfur vulcanization Sulfur vulcanization is a chemical process for converting natural rubber or related polymers into materials of varying hardness, elasticity, and mechanical durability by heating them with sulfur or sulfur-containing compounds. Sulfur forms cr ...

of rubber, and other industrial applications.

Applications

Known as ziram in agriculture, it was introduced in the United States in 1960 as a broad-spectrum fungicide. It was used to address scab on apples and pears, leaf curl in peaches, and

anthracnose A plant canker is a small area of dead tissue, which grows slowly, often over years. Some cankers are of only minor consequence, but others are ultimately lethal and therefore can have major economic implications for agriculture and horticultur ...

and

blight Blight refers to a specific symptom affecting plants in response to infection by a pathogenic organism. Description Blight is a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral orga ...

in tomatoes. In 1981, additional uses for ziram were approved, including the prevention of leaf blight and scab on almonds, shot-hole in apricots, brown rot and leaf spot in cherries, and scab and anthracnose in pecans. Ziram also began to be used on residential ornaments as a bird and mammal repellent. As a protectant fungicide, it active on the plant’s surface where it forms a

chemical A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., w ...

barrier between the plant and a fungus. A protectant fungicide is not absorbed into the plant and must be applied prior to infection. Ziram can either be directly sprayed on to a plant’s leaf or it can be used as a soil and seed treatment. The top five crops ziram is used on are:

almonds The almond (''Prunus amygdalus'', syn. ''Prunus dulcis'') is a species of tree native to Iran and surrounding countries, including the Levant. The almond is also the name of the edible and widely cultivated seed of this tree. Within the genus ...

peaches The peach (''Prunus persica'') is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, non-fu ...

nectarines The peach (''Prunus persica'') is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, no ...

pear Pears are fruits produced and consumed around the world, growing on a tree and harvested in the Northern Hemisphere in late summer into October. The pear tree and shrub are a species of genus ''Pyrus'' , in the Family (biology), family Rosacea ...

s, and table and

raisin A raisin is a dried grape. Raisins are produced in many regions of the world and may be eaten raw or used in cooking, baking, and brewing. In the United Kingdom, Ireland, New Zealand, and Australia, the word ''raisin'' is reserved for the ...

grapes. Alternatively, ziram is used as an additive ingredient in industrial

adhesive Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advant ...

caulking Caulk or, less frequently, caulking is a material used to seal joints or seams against leakage in various structures and piping. The oldest form of caulk consisted of fibrous materials driven into the wedge-shaped seams between boards on ...

, and paint. It also serves as a

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

and

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...

repellent on outdoor ornamental items.

Chemistry

The compound is a prototypical zinc dithiocarbamate, a broad class of

es with the formulae Zn(R₂NCS₂)₂, where R can be varied. Such compounds are produced by treating zinc and

dithiocarbamate In organic chemistry, a dithiocarbamate is a functional group with the general formula and structure . It is the analog of a carbamate in which both oxygen atoms are replaced by sulfur atoms (when only 1 oxygen is replaced the result is thioca ...

(R₂NCS₂⁻), as illustrated with dimethyldithiocarbamate: :2 (CH₃)₂NCS₂⁻ + Zn²⁺ → Zn((CH₃)₂NCS₂)₂ Annually, approximately 1.9 million pounds of the active ziram ingredient are used. Ziram is often sold in powder or granule form. Zinc bis(diethyldithiocarbamate) complexes degrade thermally to give

zinc sulfide Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various ...

Structure

Compounds of the type Zn(S₂CNR₂)₂ are dimeric, i.e. their proper formula is n(S₂CNR₂)₂sub>2. Each Zn center is in a distorted pentacoordinate site, with four Zn-S bonds of 2.3 Å length and one Zn---S interaction >2.8 Å in length. Mono-zinc derivatives are obtained by adding strong ligands (L) such as amines, which give adducts Zn(S₂CNR₂)₂L. NAFQUGEtMedtcskewview

Ecological effects

Ziram only moderately persists in soils, as it has a field

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ...

of 30 days In water, ziram is the most stable of all metallic dithiocarbamate fungicides, which means

biodegradation Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegra ...

is rather slow. If ziram reaches the bottom of a body of water, it may stay there for months. The U.S.

Environmental Protection Agency A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale ...

has concluded that ziram poses a low toxicity risk to mammals, a moderate risk to birds, and a high risk to aquatic species. After reviewing studies that investigated the effect of ziram on aquatic organisms, the

Pesticide Action Network Pesticide Action Network (PAN) is "an international coalition of around 600 NGO A non-governmental organization (NGO) or non-governmental organisation (see spelling differences) is an organization that generally is formed independent from ...

Pesticide Database concluded that its LC₅₀dose (amount of pesticide that is lethal to 50% of the test organisms within the stated study time) for

amphibians Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbo ...

places it in the "highly toxic" category.

References

External links

* http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-ziram/ziram-ext.html *{{PPDB, 684 Fungicides bis