Air-sensitive liquids

Synthesis. The N-silyl-P-trifluoroethoxyphosphoranimine reagents, used as "monomers in this polymer synthesis, are readily prepared from either PCU or PhPCI2 in a straightforward, 3-step reaction sequence as described elsewhere, (u -16) These compounds are obtained as colorless, distillable, air-sensitive liquids in yields of 50-75% based on starting PCU or PhPCI2. 

Colorless, hygroscopic, air sensitive liquid with a faint, pleasant, aromatic odor. Odor threshold concentration in water is 10 ppm (Buttery et ah, 1988). 

Diazadiphospholes (182) (R = Me, Ph) are obtained from the condensation of methylene bis(dichlorophosphine) and a hydrazine (Scheme 56) <85AG127>. l-Phenyl-l,2,3,5-diazadiphosphole is a colorless, air-sensitive liquid. It is not alkylated by methyl iodide or trimethyloxonium tetra-... 

Tetracarbonylfoctahydrotriborato(l-)] manganese is an air-sensitive liquid that decomposes slowly (about 5% in 4 days) at room temperature as a neat liquid in a vacuum. It is soluble in benzene, toluene, dichloromethane, diethyl ether, and tetrahydrofuran (THE), but decomposes upon heating at reflux in these solvents (especially in THF). Gas-phase thermal decarbonylation or solution photodecarbonylation of (CO)4Mn(B3H8) yields the novel and reactive compound (CO)3Mn(B3H8), in which the octahydrotriborate(l-) ligand is tridentate.3... 

A series of homoleptic Nbrv dialkylamido compounds has been obtained as highly air sensitive liquids by spontaneous reduction of [Nb(NR2)5] (R = Et, Pr", Bu" Table 41). Aminolysis of either Nbv or NbIV dialkylamides provided mixed species.256 The existence of quadrivalent tantalum dialkylamides is still questionable. [Ta(NEt2)4] was reported to have been detected during the thermolysis of [Ta(NEt2)5],263 which led predominantly to the Tav nitrene (2 Section 34.2.3.4.ii), but other workers could not find any evidence for its formation in a similar experiment.282 [Ta(NMeBu)4] has been reported to be formed in the decomposition of the corresponding pentavalent dialkylamide. 

The volatile, air-sensitive liquid species (CH3)2A1B3H8 and (CH3)2GaB3Hg are prepared by the direct reaction of the corresponding main group metal halide and salts of the [B3H8] ion, in the absence of solvent (178). The reaction of (CH3)2A1B3H8 and Al(BH4)3 results in the species (BH4)2A1B3H8. These small metallaboranes are fluxional in solution and have limited thermal stability at room temperature. 

Fig. 1.10. Transfer of air-sensitive liquids from metal cylinders, (a) A three-way metal stopcock constructed for use with syringes may be modified by the addition of a threaded fitting so that it mates with a lecture bottle. The side inlet is used to purge the apparatus initially and to blow liquid out of the syringe needle at the completion of the transfer. The cylinder is put under a low pressure of inert gas before the transfer is begun, (b) Sometimes air-sensitive liquids are sold in siphon-type cylinders, and the liquid from such a cylinder can be dispensed as shown here. As with the previous example, inert gas is used to force the liquid out of the cylinder.

H. Spectroscopic Measurements. The sampling of air-sensitive liquids for NMR and IR spectroscopy is often most conveniently performed by syringe. Small rubber septa are available which fit 5-nim and other small NMR tubes and... 

Laser Raman spectroscopy is well suited for the study of air-sensitive liquids because the sample may be contained in an all-glass cell.21 Such a cell is much easier to load on a vacuum line and to maintain leak-free than is an infrared cell. Also, such a tube is easier to heat or cool than the typical IR cell. 

Only few examples of 1,2,3,5-diazadiphospholes 23 were reported in the literature. The preparation of 1-phenyl-1,2,3,5-diazadiphosphole by the condensation of methylene bis(dichlorophosphine) and a hydrazine in the form of a colorless, air-sensitive liquid is described in CHEC-II(1996) <1996CHEC-II(4)771>. No new research on the preparation and chemistry of 1,2,3,5-diazadiphospholes has been published in the last decade. 

Dlethylstibano 4-Methylphcnyl Tellurium1 A mixture of 0.72 g bis[4-methylphenyl] ditellurium (1.6 mmol) and 0.59 g tetraethyldistibane (1.6 mmol) is stirred under argon at 25° for 1 h. The orange, air-sensitive liquid (very soluble in non-polar solvents) is obtained in quantitative yield. 

Complexes with Electrophiles An ether s nonbonding electrons also stabilize borane, BH3. Pure borane exists as a dimer called diborane, B2H6. Diborane is a toxic, flammable, and explosive gas, whose use is both dangerous and inconvenient. Borane forms a stable complex with tetrahydrofuran. The BH3 THF complex is commercially available as a 1 M solution, easily measured and transferred like any other air-sensitive liquid reagent. The availability of BH3 THF has contributed greatly to the convenience of hydroboration (Section 8-7). 

Upon treatment of bis(dimethylsilyl)ethyne 62 with trialkylborane, 1,1-organoboration took place with formation of 63, which by hydrosilylation of the C=C bond of the alkyl group resulted in the formation of the new seven-membered heterocycle 64 (Scheme 13). The presence of the SiH—B bridge in 63 was confirmed unequivocally by IR, 111, 13C, and 29Si NMR spectroscopic evidence <1999AGE124>. Compound 64 was isolated by distillation as a colorless, extremely air-sensitive liquid. 

The mercury sensitized photolysis of a mixture of F3 SiSip3 and PF3 affords P(SiF3)3 as a colorless air-sensitive liquid. It reacts with a deficiency of water to give (F3Si)2PH and F3SiPH2 and with bromine to give PBrs and F3SiBr. ... 

The compound Fe(CO)4PFs is a yellow air-sensitive liquid whose infrared spectrum [2101 (w), 2094 (w), 2021 (vs), 2004 (vs), 1996 (vs), 1970 (vw), 1960 (vw) cm i] indicates that it exists as a mixture of the axial and equatorial substituted isomers. All attempts to distinguish these isomers by nmr have failed, so that a rapid interconversion must be occurring. ... 

The arsenic and antimony pentahalides EX5 (E group 15 element As or Sb X = F or Cl) are strong, irreversible oxidants the gas AsFs has little been used, but SbCF and SbFs are commercially available, very air-sensitive liquids which are used in dry and deoxygenated dichloromethane and liquid sulfur dioxide respectively. SbCls is easier to handle than SbFs which gives the dangerous HF by reaction with moist air. Moreover, SbCls is conveniently used in dichloromethane whereas SbFs is best used in liquid SO2. On the other hand, the side products (halogenation) are more frequently encountered with SbCls than with SbFs. The redox process follows ... 

The thiarsole 32 is a pale yellow air-sensitive liquid, which on standing at ambient temperature for several days decomposes with the formation of a white solid <2000JA7012>. 

Primary phosphines are generally air-sensitive liquids with foul odors. They will oxidize very easily in the presence of oxygen, and a number of primary phosphines are pyrophoric. The use of bulky R groups can effectively improve resistance towards oxidation and these compounds can be isolated as solids.27-30... 

Figure 17. Conical shaped volumetric storage vessel for air sensitive liquids.

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