4 added 10 characters in body edited Nov 1 '15 at 19:58 M.A.R. 7,0611313 gold badges5656 silver badges8282 bronze badges Pearson's HSAB theory provides a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-softnucleophile–soft electophile.  In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. Pearson's HSAB theory provides a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-soft electophile. In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. Pearson's HSAB theory provides a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile–soft electophile.  In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. Bounty Ended with 25 reputation awarded by Community♦ occurred Nov 1 '15 at 14:50 3 added 3 characters in body edited Oct 25 '15 at 14:01 Marko 7,72144 gold badges4444 silver badges120120 bronze badges Pearson's HSAB theory givesprovides a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-soft electophile. In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. Pearson's HSAB theory gives a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-soft electophile. In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. Pearson's HSAB theory provides a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-soft electophile. In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. 2 added 59 characters in body edited Oct 24 '15 at 18:01 Marko 7,72144 gold badges4444 silver badges120120 bronze badges Pearson's HSAB theoryHSAB theory gives a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-soft electophile. In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. Pearson's HSAB theory gives a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-soft electophile. In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. Pearson's HSAB theory gives a simple explanation. When the reaction proceeds via $$S_N1$$, a hard acid (electrophile) is firstly generated (the carbocation) which interacts with the harder part of the nitrite anion an that's the oxygen-hard nucleophile. The $$S_N2$$ proceeds smoothly for the pair soft nucleophile-soft electophile. In the given example the soft electrophilic carbon reacts with the soft center of the nitrite anion, and that's the nitrogen atom. In the former case, the silver coordinated to the oxygen definitely weakens its nucleophilicity. The formed carbocation has to be pretty hard and not so much stabilized by the solvent for the O-attack to be operative. 1 answered Oct 24 '15 at 16:20 Marko 7,72144 gold badges4444 silver badges120120 bronze badges