Phosphine‐Stabilized Pnictinidenes

Abstract

The reaction of the intramolecular germylenephosphine Lewis pair (o-PPh 2 )C 6 H 4 GeAr* (1) with Group 15 element trichlorides ECl 3 (E=P, As, Sb) was investigated. After oxidative addition, the resulting compounds (o-PPh 2 )C 6 H 4 (Ar*) Ge(Cl)ECl 2 (2: E=P, 3: E=As, 4: E=Sb) were reduced by using sodium metal or LiHBEt 3 . The molecular structures of the phosphine-stabilized phosphinidene (o-PPh 2 )C 6 H 4 (Ar*)Ge(Cl)P ( 5), arsinidene (o-PPh 2 )C 6 H 4 (Ar*)Ge(Cl)As ( 6) and stibinidene (o-PPh 2 )C 6 H 4 (Ar*)Ge(Cl)Sb ( 7) are presented; they feature a two-coordinate low-valent Group 15 element. After chloride abstraction, a cyclic germaphosphene [(o-PPh 2 )C 6 H 4 (Ar*)GeP] [B(C 6 H 3 (CF 3 ) 2 ) 4 ] (8) was isolated. The 31 P NMR data of the germaphosphene were compared with literature examples and analyzed by quantum chemical calculations. The phosphinidene was treated with [iBu 2 AlH] 2 , and the product of an AlÀ H addition to the low-valent phosphorus atom (o-PPh 2 ) C 6 H 4 (Ar*)Ge(H)P(H)Al(C 4 H 9 ) 2 ( 9) was characterized.

Crystalline heaviest pnictogen-dipyrromethenes: isolation, characterization, and reactivity

“…6 Since the first base-stabilized stibinidene IV reported by the group of Dostál in 2010 (Fig. 1b), 7 several intermolecularly carbene-stabilized stibinidenes V 8 and intramolecularly phosphine-supported stibinidene VI 9 have been structurally characterized by Bertrand, Hudnall, Schulz, and Wesemann et al Among them, only one cyclic dicoordinate stibinidene ( VI ) was isolated and no species features a six-membered framework. Thus, readily accessible examples of base-stabilized stibinidenes with diverse electronic and steric structures are desirable.…”

Stiba‐, Arsa‐ and Phosphastannenes: Syntheses and Reactivities

“…9 exhibits an As−P distance of 2.2766(6) Å which lies in the range of phosphine adducts of arsinidenes [2.2082(5)–2.2710(7) Å] [6b, 10, 14] . The Sb−P bond in 10 of 2.5062(8) Å can be compared with Sb−P single bonds [2.4867(4)–2.565(1) Å] found in the literature [9, 15] …”

“…The P−P bond lengths found in 8 [2.1396(6) Å] can be compared with phosphine adducts of phosphinidenes [9, 13] . 9 exhibits an As−P distance of 2.2766(6) Å which lies in the range of phosphine adducts of arsinidenes [2.2082(5)–2.2710(7) Å] [6b, 10, 14] .…”

“…Starting with an intramolecular stannylene triarylphosphine Lewis pair (1) the protocol for the synthesis of the Group 15 stannenes follows the synthesis of the homologous germanium pnictinidenes. [9] After addition of the respective trihalides ECl 3 (E = P, As, Sb) at the stannylene moiety reduction was carried out in the case of phosphorus and arsenic addition products using hydride substitution at the Group 15 element followed by spontaneous reductive elimination of hydrogen (Scheme 2). [10] We were not able to isolate addition products 2 and 3 due to problems with the stability and purity of the compounds.…”

Reactivity of the stibinidene complex [ClSb{Cr(CO)5}2(thf)]

“…This changed in recent years when new systems to stabilize the stibinidenes and bismuthinidenes were developed. The most significant examples are phosphine‐, [7] carbene‐ [8] and N,C,N pincer‐stabilized [9] pnictinidenes. Especial the later ones got some attention as ligands in transition metal complexes, [10] in reactions with alkynes [11] or as catalysts [12] .…”