Synthesis and reactivity of low-valent group 14-15 compounds

Abstract

The synthesis, characterization and preliminary reactivity of a new diphosphine is discussed. Calculations indicated a favorable dissociation of the central P-P bond, corresponding to roughly 100kJ/mol relaxation energy for the full system. Reactions of (Dipp[subscript 2]C[subscript 2] H[subscript 4]N[subscript 2]P)[subscript 2] with elemental phosphorus (P[subscript 4]), sulfur (S[subscript 8]), oxygen (O[subscript 2]), selenium (Se[superscript 0]) and tellurium (Te [superscript 0]) yielded the trans,trans-tetraphosphabicyclobutane (LP-P[subscript 4]-PL), persulfide/sulfide (LP-S-S-PL/LP-S-PL), ethereal oxidative products (LP(O)-O-(O)PL, LP(Se)-Se-PL) as well as bridging selenide (LP-Se-PL) and telluride (LP-Te-PL) species. Reactions with boranes (BR[subscript 3], R = H or C[subscript 6]F[subscript 5]) supported an FLP-type reactivity profile (LP[arrow right]BR3 ) and subsequent hydrogen abstraction forming LPH[arrow right]BR[subscript 3]. Activation of heteroallenes including CS[subscript 2], Ph-NCO, and Ph-NCS was achieved, forming the corresponding insertion products (LP-C(=R)-X-PL). The nucleophilic ring-opening of S[subscript 4]N[subscript 4] with carbenes was investigated. IMes formed IMes=N-S[subscript 3]N[subscript 3] while more electrophilic carbenes formed zwitterionic R-S-N-S[subscript 4]N[subscript 3] (R = SIPr, CAAC) structures. Introduction of nucleophilic solvents induced degradation of the S[subscript 3]N[subscript 3] rings to R=NSNSS (R = IMes, SIPr) structures.