Fluorine molecule crystal structure

Another example of a C—F bond participating in hydrogen bonding has been found in calcium 2-fluorobenzoate dihydrate (Karipides and Miller, 1984). In the crystal structure of this compound the Tip. . . q distance between the fluorine and a water molecule bound to the calcium as a ligand was 299.4 pm, and the hydrogen bond angle was 170°. 

Fig. 16 Crystal structure of the BA/PFBA cocrystal viewed along the stacking axis. Interstack hydrogen bonding involving the carboxylic acid groups is shown as dashed lines. Hydrogen atoms are not shown, and the fluorine atoms of the PFBA molecules are shown in green...

Figure 20 The crystal structure of pure diol 14 projected in the be plane, and showing an edge-on view of two corrugated hydrogen-bonded layers. Each layer in the compound is built from enantiomerically pure molecules, but adjacent layers have opposite handedness. Fluorine atoms are designated by vertical hatching.

C6C15) with dimethylsulfoxide (DMSO), which leads to the synthesis of [Tl2 Au(C6F5)2 2 p-DMSO 3] or [Tl2 Au(C6Cl5)2 2 h-DMSO 2]ra, respectively.62 The crystal structure of the complex with fluorine shows a monodimensional polymer formed by repetition of [Au--Tl(p-0 = SMe2)3Tl] units, with gold-thallium interactions of 3.2225(6)-3.5182(8), while the pentachlorophenyl derivative contains two bridging DMSO molecules and an additional [Au(C6Cl5)2] anion. In addition, a thallium-thallium interaction of 3.7562(6) A appears in the latter (Fig. 21). 

The first unsymmetrically substituted tetrakis(silyl)hydrazine that was determined by a crystal structure is the IV,jV -[bis(difluorophenylsilyl)]-/V,Ai -[bis(trimethylsilyl)]hydrazine 83 [see Eq. (22)].16 Like those of 77 and 79, the N atoms of 83 show a planar coordination geometry, as the angle sum is found to be 360°. Because of the electron withdrawing effect of the fluorine atoms, these Si—N bonds are shortened compared to the other Si—N bonds of this molecule (Table XIV). The fluorine atoms of... 

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