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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: PAKMAN on December 24, 2004, 10:50:23 AM

Title: METHANE AND NUCLEOPHILES
Post by: PAKMAN on December 24, 2004, 10:50:23 AM

 :)HI  Can anybody answer the following question for me,

'Explain why methane does not react with reagents such as nucleophiles and electrophiles?'

sumbdy help plz!!
thanks, PAKMAN ;D

Title: Re:METHANE AND NUCLEOPHILES
Post by: movies on December 24, 2004, 01:13:02 PM

Well, think about what happens when a nucleophile attacks some molecule that it can react with.  What happens after (or rather, as) the nucleophile attacks?

Title: Re:METHANE AND NUCLEOPHILES
Post by: movies on December 24, 2004, 08:52:18 PM

Are you familiar with the S_N2 reaction mechanism?  Review that and then think about what else you need for a substitution reaction besides a nucleophile.

Title: Re:METHANE AND NUCLEOPHILES
Post by: Donaldson Tan on December 24, 2004, 10:14:25 PM

electrophiles react with nucleophiles, because electrophiles are in need of electron pairs and electron pairs are present and available for bonding on electrophiles.

are there any electron pair available for chemical reaction in the methane molecule?

Title: Re:METHANE AND NUCLEOPHILES
Post by: Donaldson Tan on December 25, 2004, 05:05:36 AM

note the carbon atom in methane has fulfilled the octet rule as well, so it isn't in need of electron pairs.

Title: Re:METHANE AND NUCLEOPHILES
Post by: maxyoung on December 28, 2004, 05:21:34 AM

Quote from: geodome on December 25, 2004, 05:05:36 AM

note the carbon atom in methane has fulfilled the octet rule as well, so it isn't in need of electron pairs.

I doubt whether we could conlude from this methane is not an electrophile.
carbon atomes in ketones all fulfill octet rule, but they are electrophiles, right?
I think the reason should be carbon and hydrogen have approximate the same electronegativity. carbon atom is neither positively nor negatively charged.

Title: Re:METHANE AND NUCLEOPHILES
Post by: dzxy on December 28, 2004, 06:06:42 PM

I definitely agree with you MaxYoung!

Title: Re:METHANE AND NUCLEOPHILES
Post by: Donaldson Tan on December 28, 2004, 10:10:58 PM

I was refering to the carbon atom itself being not able to be a site for electrophillic or nucleophillic site, since it's neither electron deficient nor contain lone pairs.

carbonyl in ketone are capable to act as nucleiphiles because of the lone pairs present on the oxygen atom.

Title: Re:METHANE AND NUCLEOPHILES
Post by: maxyoung on December 29, 2004, 06:21:28 AM

only one reason cannot explain the problem. for example,
ethylene doesn't contain lone pairs, but it can be a nucleophile.
halide is not electron deficient, but it can be electrophilic

methane is neither electrophilic nor nucleophilic, because
it fulfills octet rule
the carbon atom is not charged
it doesn't have lone pairs or pi bonds

can anyone give some more?

Title: Re:METHANE AND NUCLEOPHILES
Post by: nocommentes on January 10, 2005, 09:22:23 AM

look at picture

Title: Re:METHANE AND NUCLEOPHILES
Post by: dexangeles on January 10, 2005, 11:51:58 PM

i agree with macyoung and mitch,

but...mitch has a point

answers are based on a specific organic compound asked in the question, and we have to base everything on it, so with it's carbon fulfilling the octet rule by being bonded to four others, its already given that carbon has no formal charge

but at the same time, their eclectronegativity is a good thing to bring up :)

Title: Re:METHANE AND NUCLEOPHILES
Post by: nocommentes on January 13, 2005, 04:50:46 AM

Still CH4 can react with electrofils!!!! It's known that in superacidic acid(HSO3F/SO2(liquid)/SbF5) the presence of CH5(+) is detected!!! But to say the truth, sigma bond C-H is nucleophil in this case.