The Thionyl chloride, with the CAS registry number 7719-09-7,is also known as Thionyl dichloride. It belongs to the product categories of Solutions and Reagents;Reagent Grade.This chemical's molecular formula is Cl₂OS and molecular weight is 118.96. What's more,Its systematic name is Thionyl chloride.It is Colorless to slightly yellow liquid,which reacts violently with water,incompatible with most common metals,strong reducing agents,strong bases,alcohols,amines.It is highly corrosive and toxic. Long-term inhalation of low concentrations or short-term inhalation of high concentrations has adverse health effects.

Physical properties about Thionyl chlorideare:
(1)ACD/LogP:  -0.244; (2)# of Rule of 5 Violations:  0; (3)ACD/LogD (pH 5.5):  -0.24; (4)ACD/LogD (pH 7.4):  -0.24; (5)ACD/BCF (pH 5.5):  1.00; (6)ACD/BCF (pH 7.4):  1.00; (7)#H bond acceptors:  1; (8)#H bond donors:  0; (9)#Freely Rotating Bonds:  0; (10)Index of Refraction:  1.593; (11)Molar Refractivity:  20.61 cm3; (12)Molar Volume:  60.808 cm3; (13)Surface Tension:  76.7279968261719 dyne/cm; (14)Density:  1.956 g/cm3; (15)Enthalpy of Vaporization:  31.7 kJ/mol; (16)Boiling Point:  79 °C at 760 mmHg; (17)Vapour Pressure:  100.259002685547 mmHg at 25°C.

You can still convert the following datas into molecular structure:
(1)SMILES:ClS(Cl)=O;
(2)Std. InChI:InChI=1S/Cl2OS/c1-4(2)3;
(3)Std. InChIKey:FYSNRJHAOHDILO-UHFFFAOYSA-N.

Preparation of Thionyl chloride:
The main industrial synthesis involves the reaction of sulfur trioxide and sulfur dichloride:
                         SO3 + SCl2 → SOCl2 + SO2
it also can  syntheses from phosphorus pentachloride or chlorine:
                         SO2 + PCl5 → SOCl2 + POCl3
                         SO2 + Cl2 + SCl2 → 2 SOCl2
                         SO3 + Cl2 + 2 SCl2 → 3 SOCl2
The first of the above three reactions also affords phosphorus oxychloride (phosphoryl chloride), which resembles thionyl chloride in many of its reactions.

Uses of Thionyl chloride:
Thionyl chloride is mainly used in the industrial production of organochlorine compounds, which are often intermediates in pharmaceuticals and agrichemicals. It is used to convert carboxylic acids to  acyl chlorides and alcohols to the corresponding alkyl chlorides via an internal nucleophilic substitution.It is a component of lithium-thionyl chloride batteries, where it forms the anode with lithium as the cathode. In military usage, thionyl chloride is used in the "di-di" method of producing G-series nerve agents.

Safety Information of Thionyl chloride:
The Thionyl chloride is harmful by inhalation, in contact with skin and if swallowed.And it Causes severe burns. But there is limited evidence of a carcinogenic effect. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. When you use it wear suitable protective clothing, gloves and eye/face protection. After contact with skin, wash immediately with plenty of soap-suds.In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)Take off immediately all contaminated clothing.

The toxicity data of Thionyl chloride as follows: