 <unk> compounds are typically prepared by <unk> of antimony halides with <unk> reagents . A large variety of compounds are known with both Sb ( III ) and Sb ( V ) centers , including mixed <unk> @-@ organic derivatives , anions , and <unk> . Examples include Sb ( C6H5 ) 3 ( <unk> ) , <unk> ( C6H5 ) 4 ( with an Sb @-@ Sb bond ) , and cyclic [ Sb ( C6H5 ) ] n . <unk> <unk> compounds are common , examples being Sb ( C6H5 ) 5 and several related halides . 
