Science and Technology news... :: View topic - Why ozone (O(O2)) is not an anhidride? cfr. SO2

Angelo · Guest

On 8 Ott, 03:52, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
[quote]"Angelo" <patri...@libero.it> wrote in message

news:b5e124c7-01e3-423a-800d-31f5e95200a7@m74g2000hsh.googlegroups.com...

On 4 Ott, 14:49, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
"Angelo" <patri...@libero.it> wrote in message

news:25854257-d070-4b04-b6e8-a856f7543c16@d70g2000hsc.googlegroups.com...
On 3 Ott, 08:37, Angelo <patri...@libero.it> wrote:
On 3 Ott, 08:04,Angelo <seir...@libero.it> wrote:
As in the subject, what prevent, if any,
the ozone from behaving as an anhydride
in water solution, forming at least some
H2OO3 acid like SO2 does?
(albeit H2SO3 is not so stable to be
isolated from aqueous solutions).

IOW, it seems that O3 (OO2) is not a
sufficiently strong Lewis acid to
pick a H2O molecule and rearrange
to form te mentioned Broensted acid,
as do almost all anhydrides.

Any suggestion is welcome

Angelo

Where do you suggest the electron pair from the water molecule attaches
itself? SO2 is acidic because it can accept another electron pair (from
the
0 atom of the water molecule). Ozone isn>t because it can>t.

Please, excuse me, but are you sure?
If you make a sketch of the O3 molecule
I bet that you>ll find the central O capable
of accepting an electron pair, because you>ll
see also that, at the same time, that O can
transfer one (bonding) electron pair to one
of the two other O>s. Moreover, the central O
has a partial positive charge, and that may help.

Best regards
Angelo

You can draw a structure for ozone which leaves an empty orbital for
accepting a donor pair, but the fact that it can be drawn does not make it
[/quote]
Of course, that>s right. In my previous post I got
(most probably mistakenly) the feeling that you
were absolutely negating the possibility of any
adduct: apologies for this, my English is not so
good.

[quote]an energetically feasable structure. Your putative (H2O-O3) adduct will have
formal negative charges on two O atoms, and formal positive charges on the
two bonded to each other. Not likely to be very stable. Note you are
[/quote]
Yes, agreed. But such adduct should be a high energy
intermediate with an energy content only a bit lower
than that of the transition state through which it should
pass to arrive to the postulated acid (HO)2O^+--O^-,
let>s call it A.

[quote]transferring electrons within the molecule - it could be argued that such a
reaction should be viewed as a redox reaction rather than an acid-base
[/quote]
I agree about 'electron transfer within the molecule'
(internal redox?) but don>t see a redox reaction
simply because of the lack of a partner product.
However, the question about distinguishing redox
vs. (Lewis) acid-base reaction is tricky, see the
reactions R3N + [O] ----> R3NO: they are both
redox, and acid-base in the Lewis formalism.

Now I>d point up another issue. Let>s suppose
the acid A does form in water solution. Its
acidity should be very low, surely lower than
that of the related H2SO3. This because when
one H+ leaves A, the resulting conjugated base
A- cannot enjoy any kind of resonance stabilization,
at variance with the case of H2SO3. All this is
obviously related to the O vs. S diversity: extra
"resources" in S as you substantially said.

[quote]reaction. It is certainly not analogous to water adding to SO2, for example.
[/quote]
Yes, see also above. I *think* that at least a
feeble adduct H2O---O3 may form, much
more unlikely that it could rearrange to A.

BTW, anyone knows about IR, UV, and pH
data concerning water solution of ozone?

Best regards
Angelo

Patrizio · Guest

On 10 Ott, 17:09, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
[quote]"Angelo" <patri...@libero.it> wrote in message

news:31b9e531-9eeb-4ea2-9c14-0fa0c252548c@u29g2000pro.googlegroups.com...
On 8 Ott, 03:52, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
"Angelo" <patri...@libero.it> wrote in message

news:b5e124c7-01e3-423a-800d-31f5e95200a7@m74g2000hsh.googlegroups.com....

On 4 Ott, 14:49, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
"Angelo" <patri...@libero.it> wrote in message

news:25854257-d070-4b04-b6e8-a856f7543c16@d70g2000hsc.googlegroups.com...
On 3 Ott, 08:37, Angelo <patri...@libero.it> wrote:
On 3 Ott, 08:04,Angelo <seir...@libero.it> wrote:
[/quote]
[snip]

[quote]You can draw a structure for ozone which leaves an empty orbital for
accepting a donor pair, but the fact that it can be drawn does not make
it

Of course, that>s right. In my previous post I got
(most probably mistakenly) the feeling that you
were absolutely negating the possibility of any
adduct: apologies for this, my English is not so
good.

No problem.

an energetically feasable structure. Your putative (H2O-O3) adduct will
have
formal negative charges on two O atoms, and formal positive charges on
the
two bonded to each other. Not likely to be very stable. Note you are

Yes, agreed. But such adduct should be a high energy
intermediate with an energy content only a bit lower
than that of the transition state through which it should
pass to arrive to the postulated acid (HO)2O^+--O^-,
let>s call it A.

transferring electrons within the molecule - it could be argued that such
a
reaction should be viewed as a redox reaction rather than an acid-base

I agree about 'electron transfer within the molecule'
(internal redox?) but don>t see a redox reaction
simply because of the lack of a partner product.
However, the question about distinguishing redox
vs. (Lewis) acid-base reaction is tricky, see the
reactions R3N + [O] ----> R3NO: they are both
redox, and acid-base in the Lewis formalism.
[/quote]
Here I meant a tertiary amine (R3N, R = Methyl, Ethyl ...),
but also piridine works well, and [O] is an abbreviation
of some suitable source of an O atom, which can be
viewed as a Lewis acid capable of accepting the lone pair
in the N atom. The result is the formation of the adduct
R3N^+--O^-, a tertiary amine oxide.

[quote]Not sure what you are representing here: R3N + [O] ----> R3NO ?
If O is oxygen, it is a redox reaction,
[/quote]
Yes, but also a Lewis acid/base reaction, according to
the sheme outlined above:

L. base R3N + L. acid O ----> adduct R3NO

[quote]if O is a general electrophile, then acid-base.
[/quote]
Not always. If the atom X through which the electrofile
attacks the nucleophilic atom Y - except the (rare)
case of equal electronegativities for X and Y - there>s
also a redox reaction.

[quote]Perhaps you could provide a specific example of a case which you
would class as both redox and acid/base?
[/quote]
Well, any reaction of the type

nucleophile + eletrophile ----> adduct (plus some other product(s))

with the exception mentioned above.

[quote]Now I>d point up another issue. Let>s suppose
the acid A does form in water solution. Its
acidity should be very low, surely lower than
that of the related H2SO3. This because when
one H+ leaves A, the resulting conjugated base
A- cannot enjoy any kind of resonance stabilization,
at variance with the case of H2SO3. All this is
obviously related to the O vs. S diversity: extra
"resources" in S as you substantially said.

reaction. It is certainly not analogous to water adding to SO2, for
example.

Yes, see also above. I *think* that at least a
feeble adduct H2O---O3 may form, much
more unlikely that it could rearrange to A.

Ozone is certainly going to be weakly solvated in water, simply due to the
charge separation within the molecule. It is much more soluble than oxygen,
for example, and apparently the solubility increases at lower pH.http://cat.inist.fr/?aModele=afficheN&cpsidt=3324412
If 'ozonic acid' (?) formation was important the inverse would be true?
[/quote]
Of course, what you report rules out the formation
of such 'ozonic' acid, and thanks for the link.

[quote]Does suggest that O3H+ may be significant as pH increases, perhaps.
[/quote]
As it stands, I don>t understand. Perhaps you meant O4H-,
i.e. deprotonated H2O4 (the adduct H2O---O3)?

[quote]BTW, anyone knows about IR, UV, and pH
data concerning water solution of ozone?

Best regards
Angelo

Cheers, Robbie.
[/quote]
Best regards
Angelo

Rob · Guest

"Angelo" <patrik56@libero.it> wrote in message
news:31b9e531-9eeb-4ea2-9c14-0fa0c252548c@u29g2000pro.googlegroups.com...
[quote]On 8 Ott, 03:52, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
"Angelo" <patri...@libero.it> wrote in message

news:b5e124c7-01e3-423a-800d-31f5e95200a7@m74g2000hsh.googlegroups.com...

On 4 Ott, 14:49, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
"Angelo" <patri...@libero.it> wrote in message

news:25854257-d070-4b04-b6e8-a856f7543c16@d70g2000hsc.googlegroups.com...
On 3 Ott, 08:37, Angelo <patri...@libero.it> wrote:
On 3 Ott, 08:04,Angelo <seir...@libero.it> wrote:
As in the subject, what prevent, if any,
the ozone from behaving as an anhydride
in water solution, forming at least some
H2OO3 acid like SO2 does?
(albeit H2SO3 is not so stable to be
isolated from aqueous solutions).

IOW, it seems that O3 (OO2) is not a
sufficiently strong Lewis acid to
pick a H2O molecule and rearrange
to form te mentioned Broensted acid,
as do almost all anhydrides.

Any suggestion is welcome

Angelo

Where do you suggest the electron pair from the water molecule
attaches
itself? SO2 is acidic because it can accept another electron pair
(from
the
0 atom of the water molecule). Ozone isn>t because it can>t.

Please, excuse me, but are you sure?
If you make a sketch of the O3 molecule
I bet that you>ll find the central O capable
of accepting an electron pair, because you>ll
see also that, at the same time, that O can
transfer one (bonding) electron pair to one
of the two other O>s. Moreover, the central O
has a partial positive charge, and that may help.

Best regards
Angelo

You can draw a structure for ozone which leaves an empty orbital for
accepting a donor pair, but the fact that it can be drawn does not make
it

Of course, that>s right. In my previous post I got
(most probably mistakenly) the feeling that you
were absolutely negating the possibility of any
adduct: apologies for this, my English is not so
good.
[/quote]
No problem.

[quote]an energetically feasable structure. Your putative (H2O-O3) adduct will
have
formal negative charges on two O atoms, and formal positive charges on
the
two bonded to each other. Not likely to be very stable. Note you are

Yes, agreed. But such adduct should be a high energy
intermediate with an energy content only a bit lower
than that of the transition state through which it should
pass to arrive to the postulated acid (HO)2O^+--O^-,
let>s call it A.

transferring electrons within the molecule - it could be argued that such
a
reaction should be viewed as a redox reaction rather than an acid-base

I agree about 'electron transfer within the molecule'
(internal redox?) but don>t see a redox reaction
simply because of the lack of a partner product.
However, the question about distinguishing redox
vs. (Lewis) acid-base reaction is tricky, see the
reactions R3N + [O] ----> R3NO: they are both
redox, and acid-base in the Lewis formalism.
[/quote]
Not sure what you are representing here: R3N + [O] ----> R3NO ?
If O is oxygen, it is a redox reaction, if O is a general electrophile, then
acid-base. Perhaps you could provide a specific example of a case which you
would class as both redox and acid/base?

[quote]Now I>d point up another issue. Let>s suppose
the acid A does form in water solution. Its
acidity should be very low, surely lower than
that of the related H2SO3. This because when
one H+ leaves A, the resulting conjugated base
A- cannot enjoy any kind of resonance stabilization,
at variance with the case of H2SO3. All this is
obviously related to the O vs. S diversity: extra
"resources" in S as you substantially said.

reaction. It is certainly not analogous to water adding to SO2, for
example.

Yes, see also above. I *think* that at least a
feeble adduct H2O---O3 may form, much
more unlikely that it could rearrange to A.
[/quote]
Ozone is certainly going to be weakly solvated in water, simply due to the
charge separation within the molecule. It is much more soluble than oxygen,
for example, and apparently the solubility increases at lower pH.
http://cat.inist.fr/?aModele=afficheN&cpsidt=3324412
If 'ozonic acid' (?) formation was important the inverse would be true?
Does suggest that O3H+ may be significant as pH increases, perhaps.

[quote]BTW, anyone knows about IR, UV, and pH
data concerning water solution of ozone?

Best regards
Angelo
[/quote]
Cheers, Robbie.

Rob · Guest

"Patrizio" <patrizio.pan-2002@libero.it> wrote in message
news:39b4b561-ea93-4339-b6d7-4716927b7abb@v56g2000hsf.googlegroups.com...
On 10 Ott, 17:09, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
[quote]"Angelo" <patri...@libero.it> wrote in message

news:31b9e531-9eeb-4ea2-9c14-0fa0c252548c@u29g2000pro.googlegroups.com...
On 8 Ott, 03:52, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
"Angelo" <patri...@libero.it> wrote in message

news:b5e124c7-01e3-423a-800d-31f5e95200a7@m74g2000hsh.googlegroups.com...

On 4 Ott, 14:49, "Rob" <robbie.buckleyaoptusnet.com.au> wrote:
"Angelo" <patri...@libero.it> wrote in message

news:25854257-d070-4b04-b6e8-a856f7543c16@d70g2000hsc.googlegroups.com...
On 3 Ott, 08:37, Angelo <patri...@libero.it> wrote:
On 3 Ott, 08:04,Angelo <seir...@libero.it> wrote:
[/quote]
[snip]

[quote]You can draw a structure for ozone which leaves an empty orbital for
accepting a donor pair, but the fact that it can be drawn does not make
it

Of course, that>s right. In my previous post I got
(most probably mistakenly) the feeling that you
were absolutely negating the possibility of any
adduct: apologies for this, my English is not so
good.

No problem.

an energetically feasable structure. Your putative (H2O-O3) adduct will
have
formal negative charges on two O atoms, and formal positive charges on
the
two bonded to each other. Not likely to be very stable. Note you are

Yes, agreed. But such adduct should be a high energy
intermediate with an energy content only a bit lower
than that of the transition state through which it should
pass to arrive to the postulated acid (HO)2O^+--O^-,
let>s call it A.

transferring electrons within the molecule - it could be argued that
such
a
reaction should be viewed as a redox reaction rather than an
acid-base

I agree about 'electron transfer within the molecule'
(internal redox?) but don>t see a redox reaction
simply because of the lack of a partner product.
However, the question about distinguishing redox
vs. (Lewis) acid-base reaction is tricky, see the
reactions R3N + [O] ----> R3NO: they are both
redox, and acid-base in the Lewis formalism.

Here I meant a tertiary amine (R3N, R = Methyl, Ethyl ...),
but also piridine works well, and [O] is an abbreviation
of some suitable source of an O atom, which can be
viewed as a Lewis acid capable of accepting the lone pair
in the N atom. The result is the formation of the adduct
R3N^+--O^-, a tertiary amine oxide.

Not sure what you are representing here: R3N + [O] ----> R3NO ?
If O is oxygen, it is a redox reaction,

Yes, but also a Lewis acid/base reaction, according to
the sheme outlined above:

L. base R3N + L. acid O ----> adduct R3NO
[/quote]

No. This is strictly a redox reaction. In an acid-base reaction, there is no
formal transfer of electrons. In the example above, the electrons are
formally transferred from the N to the O. This may be readily seen by
considering whether the 'electrophile' would be removed by a stronger Lewis
base than NR3. This will not happen, as the O atom is not an electrophile,
and has formally changed its charge from 0 to -2, oxidising the N in the
process. The oxygen can only be removed by reduction of the amine oxide, not
by any conceivable acid-base process.

[quote]if O is a general electrophile, then acid-base.

Not always. If the atom X through which the electrofile
attacks the nucleophilic atom Y - except the (rare)
case of equal electronegativities for X and Y - there>s
also a redox reaction.
[/quote]
No. As above, a simple test as to whether a reaction is acid-base or redox,
is to examine the behaviour of the adduct/product in the presence of a
stronger acid or base.

For instance:
BF3 + H2O: ---> F3B-OH2 adduct
F3B-OH2 adduct + :NR3 ---> F3B-NR3 + H2O
The Lewis acid may be transferred to a stronger Lewis base, with the water O
atom retaining the previously bonding electrons.

:PR3 + [O] ---> R3PO
The oxygen cannot be removed by treatment with a stronger Lewis base, as the
P lone pair now 'belongs' to the O atom - P has been oxidised.

[quote]Perhaps you could provide a specific example of a case which you
would class as both redox and acid/base?

Well, any reaction of the type

nucleophile + eletrophile ----> adduct (plus some other product(s))

with the exception mentioned above.

Now I>d point up another issue. Let>s suppose
the acid A does form in water solution. Its
acidity should be very low, surely lower than
that of the related H2SO3. This because when
one H+ leaves A, the resulting conjugated base
A- cannot enjoy any kind of resonance stabilization,
at variance with the case of H2SO3. All this is
obviously related to the O vs. S diversity: extra
"resources" in S as you substantially said.

reaction. It is certainly not analogous to water adding to SO2, for
example.

Yes, see also above. I *think* that at least a
feeble adduct H2O---O3 may form, much
more unlikely that it could rearrange to A.

Ozone is certainly going to be weakly solvated in water, simply due to
the
charge separation within the molecule. It is much more soluble than
oxygen,
for example, and apparently the solubility increases at lower
pH.http://cat.inist.fr/?> > > > > > aModele=afficheN&cpsidt=3324412
If 'ozonic acid' (?) formation was important the inverse would be true?

Of course, what you report rules out the formation
of such 'ozonic' acid, and thanks for the link.
You>re welcome.
Does suggest that O3H+ may be significant as pH increases, perhaps.

As it stands, I don>t understand. Perhaps you meant O4H-,
i.e. deprotonated H2O4 (the adduct H2O---O3)?
[/quote]
Oops. As pH _decreases_, that should read.
Ozone will be weakly basic (possibly even dibasic) and conversion into O3H+
in acidic solution would allow more gas to dissolve.

[quote]BTW, anyone knows about IR, UV, and pH
data concerning water solution of ozone?

Best regards
Angelo

Cheers, Robbie.

Best regards
Angelo[/quote]

Angelo · Guest

in a couple of days I will repond you.

Angelo · Guest

Dear Rob
I will answer you in a couple of days or so.
Best regards
Angelo

Angelo · Guest

On 15 Ott, 19:28, Angelo <patri...@libero.it> wrote:
[quote]Dear Rob
I will answer you in a couple of days or so.
Best regards
Angelo
[/quote]
Sorry, I will be in this place most probably
on Saturday/Sunday.
Sorry again,
Angelo


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