Crystal structure of 1,2 : 5,6 : 9,10 : 13,14 : 17,18 : 21,22 : 25,26 : 29,30 : 33,34 : 37,38 decabenzo-3,7,11,15,19,23,27,31,35,39-decadehydro[40]annulene (C80H40), a 40-membered macrocyclic ring and the synthesis and characterization of its 80-(C160H80), 120-(C240H120), 160-(C320H160) and 200-(C400H200) membered ring homologues