Heavy Group 15 Element Compounds of a Sterically Demanding Bis(iminophosphorane)methanide and -methanediide

Abstract

Complexes of the heavy pnictogen elements Sb and Bi of monoanionic (C,N-chelated: Sb, Bi) and dianionic (N,C,N-pincer type: Bi) bulky substituted bis(diphenyl(arylimino)phosphorano)methane H2C(Ph2PNR)2 (R = 2,6-diisopropylphenyl (dipp)) have been prepared via metathetical reactions, and tautomerism within the monoanionic ligand backbone has been observed. The complexes have been characterized by means of X-ray analysis and NMR studies. The dianionic complex was found to feature the rare structural motif of a formal carbon–bismuth(III) double bond. The molecular structure of the solvate-free potassium salt K[HC(Ph2PNdipp)2] is reported.

Syntheses, structures and flexible coordination of sterically demanding di- and “tri”-lithiated methandiides

“…These NMR characteristics can be expected from a flexible (THF) n Li + coordination in an overall solution structure deriving from the molecular structure found for 6. In contrast, dissolving [(LLi 2 ) 2 ] 2 in neat deuterated THF gives an intense yellow solution that again shows one very broadened doublet and one broadened septet in the 1 H NMR spectrum, one broad resonance in the 31 P{ 1 H} NMR spectrum, but two resonances in the 7 Li NMR spectrum that support an overall structure comparable to that found for [LLi 2 (THF) 3 ] 5 in the solid state. Upon cooling, 1 H NMR resonances for the isopropyl protons split to two resolved doublets and one septet and, as expected, no significant changes were observed to the 31 P{ 1 H} NMR resonance.…”

“…Very similar values were found for the respective proton in [K{Ph 2 PCHPPh 2 (NSiMe 3 )}]. 3 The 31 P{ 1 H} NMR spectrum for the P III centre of 3 reveals a doublet of a 1 : 1 : 1 : 1quartet for the 7 Li-isotopomer (ca. 93%) at δ −21.1 ppm and a partially overlaid doublet of a 1 : 1 : 1-triplet for the 6 Li-isotopomer (ca.…”

“…2c Dissolving yellow crystals of [LLi 2 (THF) 3 ] 5 and colourless crystals of [LLi 2 (THF) 2 ] 6 in deuterated benzene afforded a yellow and a colourless solution, respectively, that provide very similar NMR characteristics. Both show one broadened doublet and one broadened septet for the isopropyl protons in 1 H NMR experiments and only one 7 Li{ 1 H} NMR resonance plus one broadened 31 P{ 1 H} NMR resonance. These NMR characteristics can be expected from a flexible (THF) n Li + coordination in an overall solution structure deriving from the molecular structure found for 6.…”

Synthesis of a Molecule with Five Different Adjacent Pnictogens

“…Both compounds do not contain the heaviest pnictogene bismuth. Ternary interpnictogen molecules containing bismuth are often realized with phosphazene moieties like in [BiF 2 (NPEt 2 )(HNPEt 3 )] 2 , (tms)N[P(NMe 2 ) 2 N] 2 Bi(OAc) (tms=trimethylsilyl) or C[Ph 2 P=N(dipp)] 2 BiCl (dipp=2,6‐diisopropyl‐phenyl) . Furthermore, the compound O[SiMe 2 N(R)] 2 BiP(cy) 2 (cy=cyclohexyl; R=dipp, t Bu) should be mentioned as it contains a covalent Bi−N and Bi−P bonds .…”

Organic Compounds of Bismuth: Synthesis, Structure, and Applications

“…The N,C,N-chelate bismuth complexes with the bulky bis(diphenyl(arylamino)phosphorano)methane substituents H 2 C(Ph 2 PN-Dipp) 2 can be prepared from bismuth trichloride and corresponding lithium compounds (Scheme 113) [114]. The complexes were characterized by the XRD and NMR methods.…”