Between Fluorine and Hydrogen

F-H coupling constants also decreases as one accumulates additional electronegative substituents on the carbons bearing the coupling nuclei. 

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Vicinal coupling constants between fluorine and hydrogen are generally between 18-20 Hz for both primary and secondary CF2 groups. On the other hand, H—H coupling constants between vicinal hydrogens are much smaller in these compounds, between 4 and 8 Hz. 

The rate of reaction between fluorine and hydrogen varies a great deal with conditions. Solid fluorine and liquid hydrogen explode even at 21 K but mixing of the gases at room temperature in the dark may preclude any reaction however a reaction can... 

Vicinal coupling constants between fluorine and hydrogen are generally between 18 and 20 Hz for both primary and secondary CF2 groups. 

Figure 4.13 The key to an understanding the fluorine effect observed in liquid crystals with perfluorinated bridges in their mesogenic core structure lies in the steric repulsion between fluorine and hydrogen in neighboring rings.

Enzymes can discriminate between fluorine and hydrogen atoms on molecules despite of the fact that fluorine is only slightly larger than hydrogen. For example, hydrolysis of... 

A methcxl for estimating the strength of a bond is by using calorimetry, which measures the heat of a reaction. For example, the reaction between fluorine and hydrogen... 

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