Baker, Paul K. published the artcileThe synthesis of the first examples of water-soluble seven-coordinate complexes of tungsten(II), Safety of Pyridine-3-sulfonic acid, the publication is Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry (1995), 1525-6, database is CAplus.
Reaction of the seven-coordinate complex [WI2(CO)3(NCMe)2] with two equivalent of 4-HO2CC5H4N in MeOH at room temperature gave the bis(pyridine-4-carboxylic acid) complex [WI2(CO)3(4-HO2CC5H4N)2] (1) in good yield, which, upon treatment with two equivalent of NaOH in EtOH, afforded the completely water soluble complex [WI2(CO)3(4-NaO2CC5H4N)2] (2) in good yield; reaction of the latter with an equimolar amount of 3-NaO3SC5H4N yielded [WI2(CO)3(4-NaO2CC5H4N)(3-NaO3SC5H4N)], which represents the 1st room-temperature ligand-substitution reaction in H2O of a metal carbonyl complex.
Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry published new progress about 636-73-7. 636-73-7 belongs to pyridine-derivatives, auxiliary class Pyridine,Sulfonic acid, name is Pyridine-3-sulfonic acid, and the molecular formula is C5H5NO3S, Safety of Pyridine-3-sulfonic acid.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem