19782
A series of arene ruthenium ( II ) complexes coordinated by phenanthroimidazole derivates , [ ( C6H6 ) Ru ( L ) Cl ] Cl . 2H2O ( 1b L = IP , 2b L = p - NMe2PIP , 3b L = p - MeOPIP , 4b L = p - HOPIP , 5b L = p - COOHPIP , 6b L = p - CF3PIP , 7b L = p - BrPIP ) have been synthesized in yields of 89 - 92 % under microwave irradiation in 30 min , and the crystal structure of 1b by XRD gives a typical " piano stool " conformation .
 arene ruthenium ( II ), phenanthroimidazole, [ ( C6H6 ) Ru ( L ) Cl ] Cl . 2H2O, p - NMe2PIP, p - MeOPIP, p - HOPIP, p - COOHPIP, p - CF3PIP, p - BrPIP
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 arene ruthenium ( II ), phenanthroimidazole, [ ( C6H6 ) Ru ( L ) Cl ] Cl . 2H2O, p - NMe2PIP, p - MeOPIP, p - HOPIP, p - COOHPIP, p - CF3PIP, p - BrPIP