[peacefulltortoise]

I see that HOCl has V-sharp and its structure is H - O - Cl, therefore we just care of O as centre atom. However some books show that this molecule is AX2E3 type (follow VSEPR) so Cl is centre atom and it has 2 bond pairs, 3 lone pairs. Could anyone tell me why?

[lemonoman]

I remember in my early early days of drawing lewis structures that they always said, "Put the heaviest atom at the centre" - this works well for metallocentred molecules and even for simple p-block compounds like SF₆.  But of course, that rules doesn't always apply, and can lead to poor point-group assignment.

Perhaps this is the problem?

[peacefulltortoise]

So at last which one is correct?

[Albert]

I had never seen lemonoman's structure, while I've always thought the former (looking at your post) to be the right one. So, that would be my answer, if ever asked.

[jdurg]

I have never seen lemonoman's structure either as H-O-Cl would give the proper number of bond to each species and wouldn't leave you with too many electrons on Cl and too few on O.

[Donaldson Tan]

so Cl is centre atom and it has 2 bond pairs, 3 lone pairs. Could anyone tell me why?

lemonman's structure is just a visual display of the peacefulltortoise's description.

The structure is wierd. After hydrogen has bonded with chlorine, why should chlorine even bond to oxygen?