Water hydrogen-bonded with trimethylamine

The trimethylamine/water system (for 10 isotopomers) was investigated by microwave spectroscopy69. The analysis of the rotational constants indicate a structure with an essentially linear single hydrogen bond (r = 1.818 A in 13). 

Figure 9-1 Possible structures for the hydroiiium ion. (a) The species H9O4 has been observed in the solid state and may be an important contributor in aqueous solution, (b) The species (H20)2iH exhibits a dodecahedral caged stracture in mixed water-trimethylamine cluster ions. The hydroniiim ion (not shown) is encased in the hydrogen-bonded cage with 10 non-hydrogen-bonded protons protaiding from its surface. S. Wei, Z. Shi, and A. W. Castleman, Jr., J. Chem. Phys, 1991, 94, 3268. Structure reproduced by courtesy of the American Institute of Physics.

Dicarbaclovopentaborane(5) is stable up to about 150°C, at which temperature it slowly decomposes affording tan solids and hydrogen 315). When allowed to come into contact with acetone, trimethylamine, carbon dioxide, air, or water at room temperature no noticeable reaction ensues, which is in contrast to the reactivity of most boron hydrides with these reagents. The deuterium in deuteriodiborane exchanges with the three hydrogens bonded to the boron atoms, but not with the hydrogens bonded to the carbon atoms 314). 

In addition to hydrogen halides, water is the most studied HBD in the gas phase. The structures of the complexes with water, dinitrogen, carbon monoxide, ozone, benzene, ethane, formaldehyde, formamide, 1,4-dioxane, ethylene oxide, tetrahydropyran, difluo-romethane, pyrazine, pyrimidine, pyridazine, benzonitrile, quinuclidine, ammonia, methy-lamine, trimethylamine and so on can be found in the Mogadoc database [29]. In the water-morpholine complex [30], water is hydrogen bonded to the nitrogen and not to the oxygen, as predicted by the higher HB basicity of amines than that of ethers. 

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