Molecular Formula: C₇H₇ClS
Molecular Weight: 158.65
EINECS: 204-600
Flash Point: 90 °C
Sensitive: Stench
Refractive index  n20/D 1.598(lit.)
Density: 1.22 g/mL at 25 °C(lit.)
Boiling Point: 222.4 °C at 760 mmHg
Enthalpy of Vaporization: 44.02 kJ/mol 
Vapour Pressure: 0.151 mmHg at 25°C 
IUPAC Name: 1-chloro-4-methylsulfanylbenzene
Chemical Stability: Stable under normal temperatures and pressures
Appearance P-chlorophenyl methyl sulfide (123-09-1): clear colorless to light yellow liquid
Synonyms: Methyl 4-chlorophenyl sulfide;4-Chlorophenyl methyl sulfide;4-Chlorothioanisole;1-Chloro-4-(methylthio)benzene;P-chlorophenyl methyl sulfide;P-Chlorothioanisole;1-Chloro-4-(methylthio)-benzen;Methylp-chlorophenylsulfide
Following is the molecular structure of P-chlorophenyl methyl sulfide (123-09-1):

Poison by ingestion. Mildly toxic by skin contact. An eye irritant. When heated to decomposition it emits very toxic fumes of Cl⁻ and SO_x.
 

Safety Information P-chlorophenyl methyl sulfide (123-09-1):
Hazard Codes  Xn,Xi
Xi: Irritant Xn: Harmful
Risk Statements: 22
22: Harmful if swallowed 
Safety Statements: 23-26-36/37/39
23: Do not breathe gas/fumes/vapor/spray (appropriate wording to be specified by the manufacturer) 
26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice
36/37/39: Wear suitable protective clothing, gloves and eye/face protection  
RIDADR: 2810
WGK Germany: 3
RTECS: WQ3840000
Hazard Note: Irritant/Stench
HazardClass: 6.1(b)
PackingGroup: III