Does HOF exist?

[maverick280857]

Hi

The question is merely this: is HOF known to exist at normal temperatures? Sounds dumb but half a dozen are for it (and so half a dozen against it).

Thanks and cheers
Vivek

[chem_tr]

The answer is no, since even oxygen becomes a cation against fluorine to form OF2, how can fluorine become a cation over oxygen? This is almost impossible, at least, at normal and low temperatures. At very high (plasma-forming) temperatures, something weird can happen, but I am still not sure about this.

My opinion is that HOF cannot exist on our planet ;-)

[Gokul43201]

Chem_tr : you forgot to consider one possibility. It is a crystalline solid. :biggrin:

http://srdata.nist.gov/cccbdb/exp2.asp?casno=14034798#Gurvich

[chem_tr]

Umm, I didn't understand this one... The formal charges say that, if I calculated correctly, fluorine has 1+ value which is absurd. On the other hand, oxygen must be 2+, which will cause hydrogen to be a hydride hydrogen as in BH3. Any ideas?

[Gokul43201]

I guess it is possible if you consider that each atom does not necessarily contribute a whole number of electrons to the covalent bonds...but I'm not entirely convinced that this will be very stable, given the charges below.

http://www.colby.edu/chemistry/webmo/HOF.html

According to this, the actual charges are :

H : +0.4
O : -0.3
F : -0.1

Surely it must be difficult to force -0.3 on O and -0.1 on F, but I guess it may be possible if you have bonding between two very electronegative atoms (they tend to cancel each other off ?).

It also says that :

1. A bonding orbital for O1-F2 with 1.9989 electrons has 40.03% O 1 character in a p3 hybrid and 59.97% F 2 character in a p3 hybrid.

2. A bonding orbital for O1-H3 with 1.9962 electrons has 73.62% O 1 character in a s0.80 p3 hybrid and 26.38% H 3 character in a s orbital

I do not understand one thing here. It says (in #1) that the O-F bonding orbital is p3 hybrid, not sp3. How is this possible ?

[maverick280857]

Thank you very much for the information and links...the original problem was to rank halo-oxy acids (HOCl, HOBr, HOI) in order of acidity and the natural question was why HOF wasn't on the list. Though we still do not know if it exists just as well as HOCl and HOBr do but it's still there. So thanks again :smile:...

Cheers
Vivek