In this study, we describe the crystallization of specific niobium oxide fluoride anions (either [NbOF4](-) or [NbOF5](2-)) by increasing the fluoride concentration with the appropriate use of organic bases with varied corresponding plc values to create suitable equilibria for the formation of each anion. HpyNbOF(4) (I; py = pyridine) contains the [NbOF4](-) anion, while [H-2(4,4'-bpy)]NbOF5] (II; 4,4'-bpy = 4,4'-bipyridyl) contains the [NbOF5](2-) anion; their identity is correlated with reagent ratios. The increase of basic species (proton acceptors) results in an increase in the fluoride concentration and high fluoride-containing anions. The crystallization of [NbOF4](-) in [NbO2/2F4](infinity) chains in I was controlled with the use of weak base pyridine (pK(a) = 5.23), while isolated [NbOF5](2-) crystallized in II with strong base 4,4'-bipyridyl (pK(a) = 10.5). This approach can be broadly applied to target-specific basic building units for fundamentally new and potentially functional solid-state materials.