Iodophosphane selenides: Building blocks for supramolecular soft-soft chain, helix, and base-pair arrays

Structure determinations on di-tert-butyliodophosphane selenide 1 and c-hex yldiiodophosphane selenide 2 reveal that intermolecular donor-acceptor inte ractions between nucleophilic selenium atoms and electrophilic iodine atoms lead to chains or helices that are interconnected by Se Se contacts, build ing up layer structures. In the adduct of 1 with molecular iodine (3), 1 ac ts as donor through Se(=P) and as weak acceptor through I(-P). These intera ctions lead to base-pair-like dimers [tBu(2)P(Se-I-I)I](2) that are interco nnected by additional Se ... Se contacts.