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