An additional objective is to provide molecular structures with {HEAD ~ high rotational flexibility} between {TAIL ~ the silicon atoms} and the planar configurations of the aromatic moieties to permit tight bonding of the molecule to the substrate 
between
An additional objective is to provide molecular structures with { HEAD ~ high rotational flexibility } between { TAIL ~ the silicon atoms } and the planar configurations of the aromatic moieties to permit tight bonding of the molecule to the substrate
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH