# Is methyl phenyl sulfoxide optically active? [duplicate]

I am concerned about the stereogenic centres. But in this compound there is no chiral centres present. Sulphur is $\mathrm{sp^2}$-hybridized, so it cannot be chiral anyway. But I can see there is no symmetry present in this compound. Will this be a sufficient reason to tell the compound optically active?

• This compound is in fact optically active as the sulfur has 4 different substituents, one of them being a lone pair. – Tan Yong Boon Dec 31 '17 at 16:35
• That makes it chiral. But if the lone pair can umbrella-invert like ammonia you do not see optical activity. – Oscar Lanzi Dec 31 '17 at 16:54
• Possible duplicate of Can heteroatoms with lone pairs be chiral centres? – orthocresol Dec 31 '17 at 17:09