Mellor's Comprehensive treatise on inorganic and theoretical chemistry. M52 Science Ref Dictionary of inorganic compounds. Science Ref Basic work plus supplements 1-4. Beilstein's 5th supplement. The basic set plus the 5 supplements are the most extensive organic chemistry information source.
Easiest access is through the Formula Indexes.
QD 245 C65 Science Ref Background, overviews, organic chemistry data. Dictionary of organic compounds, 5th edn., 1982. QD246 D5 Science Ref 5 vols. Science Ref Multivolume, volumes added as published. Library has v1-17 and a supplemental volume.