Table 1 Molecular structures and physicochemical properties of azoxystrobin and chlorothalonil

Structure

Chemical name

Methyl (E)-2-{2-[6-(2-cyanophenoxy) pyrimidin-4-yloxy]phenyl}-3methoxy-acrylate

Tetrachloroisophthalonitrile

Molecular weight

403.4 g mol⁻¹

265.9 g mol⁻¹

Log K_OW

2.5 (20 °C)

2.92 (25 °C)

Vapor pressure

1.1 × 10⁻⁷ mPa (20 °C)

0.076 mPa (25 °C)

Solubility

In water 6.7 mg L⁻¹ (pH 7, 20 °C)

In hexane 0.057, n-octanol 1.4, methanol 20, toluene 55, acetone 86, ethyl acetate 130, acetonitrile 340, dichloromethane 400 (all in g L⁻¹, 20 °C)

In water 0.81 mg L⁻¹ (25 °C)

In acetone 20.9, 1,2-dichlorethane 22.4, ethyl acetate 13.8, n-heptane 0.2, methanol 1.7, xylene 74.4 in g L⁻¹

Stability

DT₅₀ 8.7‒13.9 days at pH 7 for aqueous photolysis

Thermally stable at ambient temperatures. Stable to UV light in aqueous media and in crystalline state. Stable in acidic and moderately alkaline aqueous solutions; slow hydrolysis at pH > 9