Tetrahydridoborates

The tetrahydridoborate ion, as "sodium borohydride" NaBH is soluble in water and is similarly an excellent reducing agent in this solvent. (Lithium tetrahydridoaluminate cannot be used in water, with which it reacts violently to give hydrogen.)... 

The alkali metal tetrahydridoborates are salts those of sodium and potassium are stable in aqueous solution, but yield hydrogen in the presence of a catalyst. They are excellent reducing agents, reducing for example ion(III) to iron(II). and silver ions to the metal their reducing power is used in organic chemistry, for example to reduce aldehydes to alcohols. They can undergo metathetic reactions to produce other borohydrides, for example... 

Aluminium tetrahydridoborate is a volatile liquid. It is the most volatile aluminium compound known. It is covalent and does not contain ions but has a hydrogen-bridge structure like that of diborane, i.e. each boron atom is attached to the aluminium by two hydrogen bridges ... 

Aluminium hydride loses hydrogen on heating. It reacts slowly with diborane to give aluminium tetrahydridoborate ... 

Palladium Arsenic, carbon, ozonides, sulfur, sodium tetrahydridoborate... 

Hafnium Tetrahydridoborate. Hafnium tetrahydridoborate [25869-93-6] Hf(BH 4, is the most volatile compound of hafnium mp, 29°C ... 

Thallium(1) salts of tetrahydridoborate and aluminate are obtained from a T1(I) compound, eg, ethoxide, perchlorate, or nitrate, and LiBH or LiAlH ia ether. ThaIlium(I) tetrahydridoborate [61204-71 -5] TIBH, is unstable at 40°C, evolving diborane. Thallium(I) tetrahydridoaluminate... 

This tetrahydridoborate complex reacts with Lewis bases L such as CO, P(OMe)3, PMe3, and P Pr3 to form dihydride-osmium(II) complexes OsH2(CO) L(P Pr3 )2, whereas the reactions with electrophiles afford monohydride derivatives (Scheme 35). The reaction with HBF4-OEt2 leads to the binuclear complex [(P Pr3 )2 (CO)HOs(p,-r 4-H2BH2)OsH(CO)(PI Pr3 )2]BF4, consisting of two OsH... 

Treatment of OsT rf-T BT XCOXP Pr with ethanol under reflux does not lead to the formation of OsH2(CO)2(P Pr3)2 but instead gives the hydride-methyl osmium(II) compound OsHMe(CO)2(P Pr3)2 in good yield. 2-Methoxyethanol behaves in a manner similar to ethanol, and the reaction with the tetrahydridoborate complex yields OsH(CH2OMe)(CO)2(P Pr3)2 (Scheme 38).79... 

Downs et al. reported the synthesis of methylzinc tetrahydridoborate 164 by the two routes shown in Scheme 99.230 The compound is an extremely moisture and oxygen sensitive, colorless, polycrystalline solid, whose solid-state structure was determined by X-ray analysis. Figure 76 shows that 164 consists of helical polymers of alternating methylzinc and tetrahydridoborate ions. The zinc atom is formally pentacoordinate, making this one of the few organozinc compounds with five-coordinate zinc atom. 

Palladium Paraformaldehyde Paraldehyde Pentaborane-9 Pentacarbonyliron Arsenic, carbon, ozonides, sulfur, sodium tetrahydridoborate Liquid oxygen Alkalies, HCN, iodides, nitric acid, oxidizers Dimethylsulfoxide Acetic acid, nitric oxide, transition metal halides, water, zinc... 

Hafnium metal, analysis of, 13 87 Hafnium nitride, 13 89—90, 93 Hafnium oxide, 13 89, 93—94 reduction of, 73 84 Hafnium sulfides, 73 94 Hafnium tetrabromide, 73 93 Hafnium tetrachloride, 73 92 26 631 vapor reduction of, 73 84-85 Hafnium tetrafluoride, 73 90, 91 Hafnium tetrahydridoborate, 73 90 Hagen-Poiseuille expression/law, 27 726, 729 Hagen-Poiseuille flow, in microfluidics, 26 961... 

Studies on borohydride complexes of post-transition metals are as follows. Theoretical calculations on M(BH4) (M = Cu, Ag, Au) at the ab initio level indicate that Cu(i) and Ag(i) congeners have tetrahydridoborate structures, while the gold complex adopts a hydridoborane structure HAu(BH3).37 MeZn 2 /-BH4) 30 is prepared by addition of B2H6 to ZnMe2 or MeZnCl and Li[BH4]. The X-ray structure shows a polymeric helical arrangement of ZnMe + and [BH4]- fragments—similar to Be(BH4) or H2Ga(BH4) 50.38... 

Here, the essential reaction is the formation of the tetrahydridoborate ion and again the covalency of boron is brought up to four, i.e. ... 

Lithium tetrahydroaluminate Lithium tetrahydridoaluminate Sodium tetrahydroborate Sodium tetrahydridoborate Lithium trialkoxyhydridoaluminate Sodium bis(2-methoxyethoxy)dihydro-aluminate Diisobutylalane Tributylstannane... 

REDUCTION OF METAL CARBONYLS WITH ALKALI METALS AND SODIUM TETRAHYDRIDOBORATE IN LIQUID AMMONIA... 

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