Boron,[μ-[5,5'-bis[1-(3,5-dimethyl-2H-pyrrol-2-ylidene-κN)ethyl]-2,2',4,4'-tetramethyl-3,3'-bi-1H-pyrrolato(2-)-κN1:κN1']]tetrafluorodi-, 97% [ 1268614-83-0 ]