Pyridinium,4-[2-[[(6R,7R)-2-[(diphenylmethoxy)carbonyl]-8-oxo-7-[(2-phenylacetyl)amino]-5-thia-1-azabicyclo[4.2.0]oct-2-en-3-yl]thio]-4-thiazolyl]-1-methyl-,iodide(1:1)