4-Chloropyridine626-61-933 % similar 4-Fluoropyridine694-52-033 % similar 1,2-Di(pyridin-4-yl)ethyne73564-69-933 % similar 1,3-Bis(4′-pyridyl)propane17252-51-631 % similar Sulfur trioxide pyridine complex26412-87-331 % similar 2,4,6-Tris(4-pyridyl)-1,3,5-triazine42333-78-831 % similar 3,6-Di-4-pyridyl-1,2,4,5-tetrazine57654-36-131 % similar 4-Phenylpyridine939-23-131 % similar