19559
The observation of a bent CO ligand in the 19 - electron ruthenium adduct is a surprising result , and it provides new insight into the solution - phase behavior of 19 - electron complexes .
 Chemical: CO; Chemical: ruthenium
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: CO; Chemical: ruthenium