“…at para-(R2), meta-(R3) and ortho-(R4) positions of the phenyl ring. In reported crystallographic structures, [40,41] most frequently the bonds between two first atoms in meta and ortho-(outer) chains are perpendicular to the phenyl ring. In our case, this arrangement can explain the much lower clearing In order to achieve a flat layout of ortho-substituents, the two couples of quasi-isometric substancesindanone and coumaranone derivatives (I-2o and I-2p) and tetralone and chromanone derivatives (I-2q, I-2r, I-2s, I-4s, II-2s and II-4s) -are presented.…”