Synthesis of Stable Potassium Phosphinophosphides and Reaction with Organosilyl Halides and Chlorophosphanes.

The synthesis of sterically demanding 2,6-bis(2,4,6-trimethylphenyl)phenyl (Ter)-stabilized and H-substituted diphosphanes TerHP-PR (-) via conversion of the phosphide TerPHK () with secondary chlorophosphanes ClPR (-, where R = Pr, Ph, and Bu, respectively) is described. The diphosphanes - were deprotonated using KH in tetrahydrofuran, selectively yielding the potassium phosphinophosphides K[TerP-PR] (-). These phosphinophosphides are stable in solution as well as in the solid state and can be further functionalized via salt-metathesis reactions.

A Persistent Phosphanyl-Substituted Thioketyl Radical Anion.

Alkali metal salts, M [Ter(iPr)P-C(=S)-P(iPr) S] (M=Na, K; 2_M; Ter=2,6-bis-(2,4,6-trimethylphenyl)phenyl) containing a room-temperature-stable thioketyl radical anion were obtained by reduction of the thioketone precursor, Ter(iPr)P-C(=S)-P(iPr) S (1), with alkali metals (Na, K). Single-crystal X-ray studies as well as EPR spectroscopy revealed the unequivocal existence of a thioketyl radical anion in the solid state and in solution, respectively. The computed Mulliken spin density within 2_M is mainly located at the sulfur (49 %) and the carbonyl carbon (33 %) atoms.

Reaction of potassium phosphide KP(iPr)Ter with chalcogens, heteroallenes and an acyl chloride.

The reactivity of the secondary phosphide KP(Pr)Ter (1) (Ter = 2,6-bis-(2,4,6-trimethylphenyl)phenyl) toward small molecules is reported. Phosphide 1 displays distinct nucleophilic character and reacts selectively with chalcogens (S, Se), heteroallenes (CO, PrNCS), and an acyl chloride (AdCOCl) to give the corresponding dichalcogenophosphinates (2a, 3), phosphanyl formate (5), thiocarbamoylphosphane (6a), or acylphosphane (7a), respectively. Furthermore the follow-up chemistry of these products was investigated.

Insertion of CS into a Phosphorus-Arsenic Single Bond and Investigations on Phosphane Arsanyldithiocarboxylates.

The synthesis and reactivity of sterically demanding phosphaarsanes TerRP-AsR () is described. These species were selectively synthesized via metathesis reactions of Ter-stabilized [Ter = 2,6-bis(2,4,6-trimethylphenyl)phenyl] potassium phosphides TerRPK () with the N-heterocyclic chloroarsane ClAs{N(Bu)CH} (). Conversion of the -butyl-substituted phosphaarsane with the reactive heterocumulene CS leads to an insertion into the P-As bond, yielding the phosphane arsanyldithiocarboxylate TerRP-C(S)S-AsR () as a new structural motif.

Synthesis of Sterically Demanding Secondary Phosphides and Diphosphanes and Their Utilization in Small-Molecule Activation.

Sterically demanding secondary potassium phosphides () were synthesized and investigated. Reaction with halophosphanes () yields diphosphanes (), whereas reaction with CS yields phosphanyl dithioformates (). These can be further converted to the corresponding phosphanyl esters of dithioformic acid RP-C(S)S-PR ().

[E(μ-NBbp)] (E = P, As) - group 15 biradicals synthesized from acyclic precursors.

The synthesis of Bbp stabilized biradicals of the type [E(μ-NBbp)] (E = P, As) (Bbp = 2,6-bis[bis(trimethylsilyl)methyl]phenyl) was investigated. Contrary to the established synthetic protocol for terphenyl substituted biradicals [E(μ-NTer)] by reduction of [ClE(μ-NTer)], the analogous Bbp substituted precursor [ClE(μ-NBbp)] could only be obtained in low yields. For this reason, a new synthesis had to be found to generate [E(μ-NBbp)].