23926
A structurally unique class of hydrocarbon - soluble , ancillary - ligand - free , tetrametallic Co ( I ) and Ni ( I ) clusters is reported .
 Chemical: hydrocarbon; Chemical: Co ( I ); Chemical: Ni ( I )
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: hydrocarbon, Co ( I ), Ni ( I ) 
Answer:
 Chemical: hydrocarbon; Chemical: Co ( I ); Chemical: Ni ( I )