Methylamine molecular structure

Rank methylamine, dimethylamine, and diethylamine in order of increasing base strength. Explain your rankings in relation to molecular structure. 

PhCD2NH2,40,42 as well as the temperature independence of the Ap/f, for CD3M f and (CD3)2NH2,52 Perrin and coworkers reinvestigated these and other secondary IEs.30,31 The amines studied were methylamine (16-do,1,2,3), benzylamine (18-d), N,A -dimethy 1 ani 1 ine (19-d3), 1-benzyl-4-methylpiperidine (20-d3), pyrrolizidine (21-d), N-methy 1 norborny 1 amine (22-d2), and A -benzyl-norbornylamine (23-d). The NMR titration method [Equation (19)], which gives highly accurate results, was applied to the reporter H depicted in boldface on the molecular structures. The results are presented in Table 5. According to those data the ApK for methylamine (16) is proportional to the number of deuteriums, and for 16-18, 22, and 23 the Apper D or the AAG° per D is nearly constant, 24 cal mol-1. 

SMILES (Simplified Molecular Input Line Entry System) was invented by Weininger5 to facilitate the representation and manipulation of molecular structures using computers. It uses standard atomic symbols to represent atoms and the symbols - for single bond, = for double bond, and for triple bond. Hydrogen atoms can be represented explicitly but are almost always represented implicitly using normal conventions of valence bond theory. Single bonds need not be explicitly written. For example, propane is C-C-C or simply CCC. Methylamine is CN, and C N is hydrogen cyanide. Propene is C=CC. For more complex structures with branched bonds, parentheses are used. For example, CC(C)0 is isopropyl alcohol, whereas CCCO is propanol. 

Two structures that easily accept protons, and thus make certain molecules bases, are NH and NH. For easy identification, many bases are written with these structures tacked onto the end of the molecular formula. For example, we write the bases dimethylamine, methylamine, and aniline as (CH3)2NH, CH3NH2, and... 

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