[adamc637]

I have 2 questions which I'm just pondering because I can't answer them

First is

If triamminetetrachloroplatinum(V) ion (Pt(NH₃)₂Cl₄ ⁺) were to be put into a hexagonal planar geometry, how many geometric isomers would it have? Is it possible to have this arrangement or not from what you see from the drawings?

I drew them out, and I can't think of why it would rule hexagonal planar out other than being polar and the molecules pushing it away (which doesn't sound too plausible anyways).

Second question:
In the case of transition metals, going from group IIIB to group VB or VIB, the melting point gets higher because "the electrons are not paired". Why does having paired electrons in group VIB and up cause the boiling point to fall?