“…Structures of trans -3 and cis -3. There have been some reports on X-ray crystal structures of 9,10-dihydro-9,10-disilaanthracene derivatives. 2b-e, 9,10-Dihydro-9,10-disilaanthracene ( 4 ), 2b,e 9,9,10,10-tetramethyl-9,10-dihydro-9,10-disilaanthracene ( 5 ), 2b,c and the 9,10-dimethyl-9,10-disilaanthracene dimer 4 have folded structures along the silicon atoms at the 9- and 10-positions…”