Synthesis of bismuthanyl-substituted monomeric triel hydrides.

The syntheses and characterizations of the first bismuthanylborane monomers stabilized only by a donor in D·BHBi(SiMe) (D = DMAP 1a, IDipp 1b, IMe1c; DMAP = 4-dimethylaminopyridine, IDipp = 1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene, IMe = 1,3,4,5-tetramethylimidazol-2-ylidene) are presented. All compounds were synthesized by salt metathesis reactions between D·BHI and KBi(SiMe)(THF) and represent some of the extremely rare compounds featuring a 2c-2e B-Bi bond in a molecular compound. The products display high sensitivity towards air and light and slowly decompose in solution even at -80 °C.

Three- and Five-Membered Anionic Chains of Pnictogenylboranes.

An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H E'-BH -NMe (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2= Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H E'-BH -EH Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H E'-BH -EPh ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.

The potential of NO and O in switchable reagent ion proton transfer reaction time-of-flight mass spectrometry.

Selected ion flow tube mass spectrometry (SIFT-MS) and proton transfer reaction mass spectrometry with switchable reagent ion capability (PTR+SRI-MS) are analytical techniques for real-time qualification and quantification of compounds in gas samples with trace level concentrations. In the detection process, neutral compounds-mainly volatile organic compounds-are ionized via chemical ionization with ionic reagents or primary ions. The most common reagent ions are H O , NO and O .

Bidentate Phosphanyl- and Arsanylboranes.

A new class of neutral bidentate ligands with pnictogenyl-functional sites has been obtained. The reaction of tmeda⋅(BH I) (1, tmeda=tetramethylethylendiamine) with different phosphanides yields the corresponding bidentate phosphanylboranes tmeda⋅(BH PH ) (2 a), tmeda⋅(BH PPh ) (2 b), and tmeda⋅(BH tBuPH) (2 c). This reaction strategy could be further extended to synthesize the first bidentate arsanylborane tmeda⋅(BH AsPh ) (3).

The Lewis-Base-Stabilized Diphenyl-Substituted Arsanylborane: A Versatile Building Block for Arsanylborane Oligomers.

The synthesis and properties of the diphenyl-substituted arsanylborane Ph AsBH SMe (1) and Ph AsBH NMe (2) stabilized by a Lewis base (LB) were reported. These compounds were obtained by reaction of KAsPh with IBH -LB (LB=SMe , NMe ). Compounds 1 and 2 were used as starting materials for oligomeric/ polymeric arsinoboranes.

Depolymerization of Poly(phosphinoboranes): From Polymers to Lewis Base Stabilized Monomers.

We report on depolymerization reactions of poly(phosphinoboranes). The cleavage of the polymers [H PBH ] (2 a), [tBuHPBH ] (2 c), [PhHPBH ] (2 e) and the oligomer [Ph PBH ] (2 b), with strong Lewis bases (LBs), in particular with NHCs, leads to the corresponding monomeric phosphanylboranes R R PBH LB. It is observed that the depolymerization depends on the strength and stability of the LBs as well as on the substitution pattern of the poly(phosphinoboranes).

A Convenient Route to Mixed Pnictogenylboranes.

We report on the synthesis and characterization of mixed pnictogenylboranes. The substitution of the Lewis base SMe in (OC) W-PH BH -SMe (2) by different pnictogenylboranes ER BH -LB (E=P, As, Sb) leads to the Lewis acid/base stabilized butane analogue (OC) W-PH BH ER BH -LB (3 a, b: E=P; R=H, SiMe ; LB=NMe ; 4 a, b: E=As; R=H, SiMe ; LB=NMe ; 5: E=Sb; R=SiMe ; LB=NHC ). All of these compounds were characterized by single-crystal X-ray structure analysis, mass spectrometry, NMR, and IR spectroscopy.

Oxidation of Substituted Phosphanylboranes with Chalcogens.

The elemental chalcogens sulfur, selenium, tellurium and bis(trimethylsilyl)peroxide as an oxygen source are applied for the oxidation of the phosphanylboranes Ph P-BH ⋅NMe (1) and tBuHP-BH ⋅NMe (2). The corresponding monooxidation products Ph P(X)-BH ⋅NMe (X=O-Te, 3 a-d) and tBuHP(X)-BH ⋅NMe (X=O-Te, 4 a-d) were obtained in good yields and comprehensively characterized by single crystal X-ray structure analysis, NMR, IR spectroscopy and mass spectrometry. The first oxidation step proceeds very selectively for all chalcogenides.

Isolation and Characterization of Lewis Base Stabilized Monomeric Parent Stibanylboranes.

The synthesis of the Lewis base stabilized monomeric parent compound of stibanylboranes, "H2 Sb-BH2 ", is reported. Through a salt metathesis route, the silyl-substituted compounds (Me3 Si)2 Sb-BH2 ⋅LB (LB=NMe3 , NHC(Me) ) were synthesized as representatives of derivatives with a Sb-B σ bond. Under very mild conditions, they could be transformed into the target compounds Me3 N⋅H2 B-HSb-BH2 ⋅NMe3 and H2 Sb-BH2 ⋅NHC(Me) , respectively.