EA-1763

EA-1763, O-PPVX, V1 or propyl S-2-diisopropylaminoethylmethylphosphonothiolate, is a military-grade neurotoxic organophosphonate nerve agent related to VX as it the propyl analogue of VX. It is part of the V-series.

Chemical characteristics
Little information about EA-1763's physicochemical properties has been reported. V1 is a more viscous and less dense liquid than VX. It is colorless, odorless and tasteless in its pure form. Impure, or in the crude form, it has a characteristic viscous amber color, giving it an appearance similar to motor oil. The impure form varies several shades of amber, from a viscous liquid of a transparent pale yellow color to a pasty liquid of a semi-transparent and cloudy dirty amber color. The smell varies from engine oil to an offensive brew of organosulfur compounds and organoamines.

Its larger alkane chain pushes its melting point above that of VX. The estimated solubility of V1 in water is 4 times lower compared to VX (6.8 g/L of water at 25 °C). V1 has high solubility in organic solvents and other non-polar compounds. The stability of V1 is roughly the same as that of VX in either environment. Higher insolubility and lower volatility can slow down the process. A vapor pressure at least 3 times lower than VX is speculated.

The longer alkane chain tends to stabilize the induction of electrons from P to O, making P less electrophilic. It is expected that the persistence of V1 is slightly higher than that of VX, estimating the hydrolysis rate between ethyl and n-propyl paraoxon, is 1.6 times more persistent in neutral medium.

The lower volatility and minimal persistence difference makes VX preferable to V1.

Preparation
It is prepared by the same route as VX using propanol instead of ethanol.