\chemfig{ \mcfatomno{1}% 1 -[:90,2]\mcfatomno{2}% 2 -[,2,,,draw=none]\mcfatomno{5}% 5 -[:270,2]\mcfatomno{3}% 3 ( -[:180,2]\phantom{1}% -> 1 ) -[:45,1.131]\mcfatomno{7}% 7 -[:180,2,,,draw=none]\mcfatomno{4}% 4 ( -[:225,1.131]\phantom{1}% -> 1 ) -[:90,2]\mcfatomno{6}% 6 ( -[:225,1.131]\phantom{2}% -> 2 ) -[,2]\mcfatomno{8}% 8 ( -[:225,1.131]\phantom{5}% -> 5 ) ( -[:270,2]\phantom{7}% -> 7 ) ( -[:195.9,2.912,,,draw=none]\phantom{2}% -> 2 -[,2,,,mcfx={100}{10}]\phantom{5}% -> 5 ) ( -[:270,2,,,draw=none]\phantom{7}% -> 7 -[:180,2,,,mcfx={100}{10}]\phantom{4}% -> 4 ) }