d.在OH条件下,NH,OH也可作为氧化剂;而在 H+条件下,几乎不可能成为氧化剂。 NHOH+2H2O+2e >2NH3H2O+20H p馆=0.42V NH:OH"+2H"2e-> NH +H2O p=-1.35V NH2OH NagAsO3 NH3+NagAsO NH2OH H2O+2Fe(OH)2=NH3 2Fe(OH)3
d. 在OH-条件下,NH2OH也可作为氧化剂;而在 H+条件下,几乎不可能成为氧化剂。 NH2OH + Na3AsO3 = NH3 + Na3AsO4 NH2OH + H2O + 2Fe(OH)2 = NH3 + 2Fe(OH)3 26
4.[-1/3]0.S. HN叠氮酸(hydrogen azide,hydrogen dinitride nitrate,hydrazoic acid) N2H4+HNO2=HN3(叠氮酸)+2H2O 110°H NN.N 109 124pm 113pm spsp s sp2 102pm 171 三个σ键, 120pm 110pm 而一NN一N】 N 一个π键, 一个Π 27
4. [-1/3] O.S. HN3叠氮酸 (hydrogen azide, hydrogen dinitride nitrate, hydrazoic acid) 而 N N N N 120pm 110pm 110 o N N N H 124pm 113pm N N N H sp sp sp2 110 o 三个σ键, 一个π键, 一个 4 33 27 N2H4 + HNO2 = HN3 (叠氮酸) + 2H2O
HN3叠氮酸(hydrazoic acid) >HN3是一种易爆炸的油状物,在水中稳定,弱酸(酸性与 HAc相当),Ka=2.8×105 (1)Preparation: N2H4+HNO2=HN3 H2O NaNH2 N2O=NaNg H2O 3N2O(g)+4Na(NH3)+NHg(I)=NaNg(s)+2NaOH(NH3)+2N2(g) p N3:sp杂化 2个sp一pxo键, 2个p-p元键π
¾ HN3是一种易爆炸的油状物,在水中稳定,弱酸(酸性与 HAc相当),Ka=2.8×10﹣5 HN3叠氮酸 (hydrazoic acid) N3 - :sp杂化 4 π3 N N N py pz - 2个sp—px V键, 2个p—p S键 (1) Preparation: N2H4 + HNO2 = HN3 + H2O NaNH2 + N2O = NaN3 + H2O 3N2O(g)+4Na(NH3)+NH3(l) = NaN3(s)+2NaOH(NH3)+2N2(g) 28
(2)Chemical properties: a.HN3的氧化性与HNO3相似 Cu +3HNg=Cu(N3)2+N2+NH3 c.歧化:HN3+H2O=NH2OH+N2(Pt cat)) d.热分解:Pb(N3)2=Pb+3N2,2HN(0=H2+3N2 HN3 NaOH 撞击 Zn NaNg 用于引爆剂 Zn(N3)2tH2↑ N2↑+H2t AgN3 Cu(Na)2 Pb(Na)2 Hg(N3)2 9
(2) Chemical properties: a. HN3 的氧化性与HNO3相似 Cu + 3HN3 = Cu(N3)2 + N2 + NH3 c. 歧化: HN3 + H2O = NH2OH + N2 (Pt cat) d. 热分解: Pb(N3)2 = Pb + 3N2, 2HN3(l) = H2 + 3N2 撞击 NaOH NaN3 N2↑ +H2↑ Zn Zn(N3)2+H2↑ HN3 AgN3 Cu(N3) 2 Pb(N3)2 Hg(N3)2 用于引爆剂 29
-R" 1 mol-%CuSO4 0.1 eq.sodium ascorbate RN3+三一R H201t-Bu0H(1:1) r.t.,12-24 h (TLC) Click tris(alkyne)ODN stepwise click reactions Chemistry ●● protecting groups ◆●labels trifunctionalized ODN 30
Click Chemistry 30