22.2 Structure and Bonding 861 47 ppm GURE 22.1A ball- and-stick model of methyl- pyramidal arrangement of stable conformation has the staggered arrangement of bonds shown. Other alkyl- CH CHINH2 CI chacha cfco CHS CH,N(CH3)3 I Methylammonium N-Ethyl-N-methylcyclopentyl Benzyltrimethyl chloride ammonium trifluoroacetate ammonium iodide Ammonium salts that have four alkyl groups bonded to nitrogen are called quaternary ammonium salts 22.2 STRUCTURE AND BONDING Alkylamines: As shown in Figure 22 1 methylamine, like ammonia, has a pyramidal arrangement of bonds to nitrogen. Its H-N-H angles(106)are slightly smaller than the tetrahedral value of 109.5, whereas the C-N-H angle (112 )is slightly larger The C-N bond distance of 147 pm lies between typical C-C bond distances in alkanes (153 pm)and C-O bond distances in alcohols(143 pm) An orbital hybridization description of bonding in methylamine is shown in Fig- ure 22.2. Nitrogen and carbon are both sp-hybridized and are joined by a o bond. The FIGURE 22.2 Orbital hybridization description of bonding in methylamine. (a)Carbon has four valence electrons; each of four equivalent sp-hybridized orbitals contains one electron Nitrogen has five valence electrons. Three of its sp hybrid orbitals contain one electron each; the fourth sp hybrid orbital contains two electrons. (b)Nitrogen and carbon are connected by a o bond in methylamine. This o bond is formed by overlap of an sp hybrid orbital on each atom. the five hy drogen atoms of methylamine are joined to carbon and nitrogen by o bonds. The two remaining electrons of nitrogen occupy an sp-hybridized orbital Back Forward Main MenuToc Study Guide ToC Student o MHHE WebsiteAmmonium salts that have four alkyl groups bonded to nitrogen are called quaternary ammonium salts. 22.2 STRUCTURE AND BONDING Alkylamines: As shown in Figure 22.1 methylamine, like ammonia, has a pyramidal arrangement of bonds to nitrogen. Its H±N±H angles (106°) are slightly smaller than the tetrahedral value of 109.5°, whereas the C±N±H angle (112°) is slightly larger. The C±N bond distance of 147 pm lies between typical C±C bond distances in alkanes (153 pm) and C±O bond distances in alcohols (143 pm). An orbital hybridization description of bonding in methylamine is shown in Fig￾ure 22.2. Nitrogen and carbon are both sp3 -hybridized and are joined by a bond. The CH3NH3  Cl Methylammonium chloride NCH2CH3 CH3 H  CF3CO2  N-Ethyl-N-methylcyclopentyl￾ammonium trifluoroacetate C6H5CH2N(CH3)3  I  Benzyltrimethyl￾ammonium iodide (a quaternary ammonium salt) 22.2 Structure and Bonding 861 147 ppm 112 106 C N H H H H H (a) (b) FIGURE 22.1 A ball￾and-stick model of methyl￾amine showing the trigonal pyramidal arrangement of bonds to nitrogen. The most stable conformation has the staggered arrangement of bonds shown. Other alkyl￾amines have similar geome￾tries. FIGURE 22.2 Orbital hybridization description of bonding in methylamine. (a) Carbon has four valence electrons; each of four equivalent sp3 -hybridized orbitals contains one electron. Nitrogen has five valence electrons. Three of its sp3 hybrid orbitals contain one electron each; the fourth sp3 hybrid orbital contains two electrons. (b) Nitrogen and carbon are connected by a bond in methylamine. This bond is formed by overlap of an sp3 hybrid orbital on each atom. The five hy￾drogen atoms of methylamine are joined to carbon and nitrogen by bonds. The two remaining electrons of nitrogen occupy an sp3 -hybridized orbital. Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website