Coordination chemistry of proton. In situ synthesis and X-ray structural analysis of 2-hydroxyethanaminium picrate, HOCH2CH2NH3+C6H2N3O7-.
スポンサーリンク
概要
- 論文の詳細を見る
2-Hydroxyethanaminium picrate, HOCH<SUB>2</SUB>CH2NH<SUB>3</SUB><SUP>+</SUP>·C<SUB>6</SUB>H<SUB>2</SUB>N<SUB>3</SUB>O<SUB>7</SUB><SUP>−</SUP>, is prepared through a metathetical reaction of Mg(Pic)<SUB>2</SUB> and HOCH<SUB>2</SUB>CH<SUB>2</SUB>NH<SUB>2</SUB> (2-aminoethanol, MEA) in ethanol through in situ generation of HPic. Orange yellow crystals (MEAH<SUP>+</SUP>Pic<SUP>−</SUP>) (mp 163°C) of the "Salt" are produced alongwith the colorless Mg(CH<SUB>2</SUB>NH<SUB>2</SUB>CH<SUB>2</SUB>O<SUP>−</SUP>)<SUB>2</SUB>, even when MEA is less than 1:1 with respect to Mg(Pic)<SUB>2</SUB>. The crystals are monoclinic, space group P2<SUB>1</SUB>/c, <I>a</I>=11.797(4), <I>b</I>=14.288(3), <I>c</I>=7.124(2) Å, β=97.63(2)°, <I>Z</I>=4, <I>D</I><SUB>cal</SUB>=1.62 g cm<SUP>−3</SUP>. Structural analysis from the 1617 reflection data (<I>R</I>=0.059, <I>R</I><SUB>w</SUB>=0.056) reveals that the picric acid proton is formally transferred to the MEA nitrogen (N–H, 0.968 Å) and is merely bonded to the phenoxide of Pic (H···O<SUP>−</SUP>, 1.951 Å) and weakly also to an oxygen of <I>o</I>-nitro group of the anion (H···ONO, 2.379 Å). The transferred proton becomes an integral part of the cation MEAH<SUP>+</SUP> and completes the fourth covalent bond of the sp<SUP>3</SUP> N of MEA, and does not show any special affinity for the anionic oxygen of Pic; the N–H···O<SUP>−</SUP> (142.8°) and N–H···ONO (141.6°) angles are closely comparable.
- 公益社団法人 日本化学会の論文
著者
-
Chandra Ramesh
Institute for Research and Chemical Services, Research Oasis, Patiala House Vishnupuri Main
-
Poonia Narinder
Institute for Research and Chemical Services, Research Oasis, Patiala House Vishnupuri Main
-
Sheldrick W.
Chemistry Department, University of Kaiserslautern