Solid state structures hydrogen fluoride

Following the discovery of the above solid-state fluoride anion complex, the authors succeeded in crystallizing the bishydrochloride salt of this same system, 3. The X-ray structure of this derivative revealed the presence of two chloride counterions bound via hydrogen bonds to the diprotonated macrocycle (Figure 2). In contrast to what was seen in the case of the fluoride anion structure, in this instance neither of the counteranions is located in the plane of the sapphyrin macrocycle. Rather, they are found in near symmetric fashion ca. 1.8 A above and below the mean Nj plane. This out-of-plane binding reflects, presumably, the fact... 

For small molecules in the gaseous state, quadrupole coupling constants for deuterium and other nuclei can be determined from microwave spectroscopyS4,S6 and molecular beam resonance.43 For systems that behave differently in isolated molecules and in the condensed states, these techniques give unique information. Examples are lithium deuter-ide,61 which has an NaCl structure and therefore a zero field gradient for deuterium in the solid state, and deuterium fluoride,36 which forms strong hydrogen bonds in both the liquid and the solid state. 

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