Adducts between SF4 and a nitrogen base are easily solvolyzed by HF, yielding the protonated nitrogen base and fluoride. Salts resulting from the solvolysis of SF4 center dot NC5H5, SF4 center dot NC5H4(CH3), SF4 center dot NC5H3(CH3)(2), and SF4 center dot NC5H4N(CH3)(2) have been studied by Raman spectroscopy and X-ray crystallography. Crystal structures were obtained for pyridinium salts [HNC5H5+]F-center dot SF4 and [HNC5H5]F-[HF]center dot 2SF(4), the 4-methylpyridinium salt [HNC5H4(CH3)]F-center dot SF4, the 2,6-methylpyridinium salt [HNC5H3(CH3)(2)](2)[SF5]F-center dot SF4, and 4(dimethylamino)pyridinium salts [HNC5H4N(CH3)(2)](2)[SF5]F-center dot CH2Cl2 and [NC5H4N(CH3)(2)][HF2-]center dot 2SF(4). In addition, the structure of [HNC5H4(CH3)][HF2-] was obtained. 4,4'-Bipyridyl reacts with SF4 and 1 and 2 equiv of HF to give the 4,4'-bipyridinium salts [NH4C5-C5H4NH+]F-center dot 2SF(4) and [HNH4C5-C5H4NH2]2F(-)center dot 4SF(4), respectively. These structures exhibit a surprising range of bonding modalities and provide an extensive view of SF4 and its contacts with Lewis basic groups in the solid state. The interactions range from the strong F4S-F- bond in the previously observed SF5- anion to weak F4S---F-, (FS)-S-4(---F-)(nu) and F4S(---FHF-)(2) dative bonds.