Borderline Lewis acid (generic) Pearson borderline Lewis acid (generic)   Special class of generic used to represent "generic chemical reactivity behaviour" rather than structure. Wikipedia Page: Borderline Lewis acid (generic) is defined with respect to the entities below: The entities below are defined with respect to: Borderline Lewis acid (generic) Antimony(III) ion Bismuth ion Carbenium ion, trialkyl (generic) Cobalt(II) ion Copper(II) ion Iridium(III) Ion Iron(II) ion Lead(II) ion Nickel(II) ion Phenyl cation Ruthenium(II) ion Sulfur dioxide Tin(II) ion Trimethylborane Zinc ion chemical compound molecule metal molecular science reaction mechanism ionic material acid base geometry reactivity synthesis science knowledge chemistry Lewis