Homoleptic Pnictogen–Chalcogen Coordination Complexes

The synthesis and structural characterization of dicationic selenium and tellurium analogues of the carbodiphosphorane and triphosphenium families of compounds are reported. These complexes, [Ch­(dppe)]­[OTf]2 [Ch = Se, Te; dppe = 1,2-bis­(diphenylphosphino)­ethane; OTf = trifluoromethanesulfonate], are formed using [Ch]2+ reagents via a ligand-exchange protocol and represent extremely rare examples of homoleptic pnictogen → chalcogen coordination complexes. The corresponding arsenic compounds were also prepared, [Ch­(dpAse)]­[OTf]2 [Ch = Se, Te; dpAse = 1,2-bis­(diphenylarsino)­ethane], exhibiting the first instance of an arsenic → chalcogen dative bond. The electronic structures of these unique compounds were determined and compared to previously reported chalcogen dications.本文报道了碳二膦烷（carbodiphosphorane）与三膦鎓（triphosphenium）类化合物家族的二阳离子硒及碲类似物的合成与结构表征。该类配合物的通式为[Ch(dppe)][OTf]₂，其中Ch代表硒（Se）、碲（Te）；dppe为1,2-双(二苯基膦基)乙烷；OTf为三氟甲磺酸盐（trifluoromethanesulfonate）。这类配合物通过[Ch]²⁺试剂经配体交换法合成，属于极为罕见的均配型氮族（pnictogen）→硫族（chalcogen）配位配合物。 相应的砷基配合物亦被成功制备，通式为[Ch(dpAse)][OTf]₂，其中Ch=Se、Te；dpAse为1,2-双(二苯基胂基)乙烷，该类配合物代表了首例砷→硫族配位键的实例。本研究对这些独特化合物的电子结构进行了测定，并与此前已报道的硫族二阳离子化合物展开了对比分析。