DL Metal Hydrides

Metal Hydrides

2

1. Introduction

2. Products and Properties2.1 Alkali Hydrides - Lithium

Hydride and SodiumHydride

2.1.1 Lithium Hydride2.1.2 Sodium Hydride2.2 Binary Hydrides of

Boron – Lithium Boro-hydride, Sodium Boro-hydride, PotassiumBorohydride

2.2.1 Lithium Borohydride2.2.2 Sodium Borohydride2.2.3 Potassium Borohydride2.3 Binary Hydrides of Alu-

minum – Lithium Alu-minum Hydride (LAH)

2.4 Complex Hydrides ofLithium and Boron –Lithium Triethylboro-hydride (LTEBH)

2.5 Complex Hydrides ofSodium and Boron –Sodium Triacetoxyboro-hydride (STAB)

2.6 Complex Hydrides ofLithium and Aluminum– Lithium Tri(t-butoxy)aluminumHydride (LTTBA)

3. Safe Handling3.1 Storage3.1.1 Storage in the

Laboratory3.2 Behavior of Hydrides

towards Air3.3 Reaction with Water3.4 Handling of Solid

Hydrides3.5 Fire Fighting

3.6 Protection of Personnel3.7 First Aid3.8 Disposal of Residues

4. Packaging and Transport4.1 Solid Products4.2 Products in Solution 4.3 Packaging

5. Transport

6. Analysis6.1 Analysis of Solid

Hydrides6.2 Analysis of LAH

SolutionsDisclaimer

Contents

3

1. Introduction

Metal hydrides form a large vari-ety of compounds with diversestructures, bonding types, andchemical properties. While someof these hydrides are only of pureacademic interest – others areused on a large industrial scale. Agood review over the variety ofhydrides is given in an article inUllmann’s Encyclopedia of Indus-trial Chemistry1. The industrial useof hydrides has been growing overthe last decades and Chemetallhas acquired a broad know-how inthe manufacture and handling ofcommercial quantities.

The purpose of this brochure is togive an overview of the metalhydrides available from Chemetalland to share our technical knowledge with our customers. It is our intention to make our customers familiar with the properties of the various hydridesand to give a general handlinginstruction.

A short overlook over their chemi-cal behaviour is given in a trifoldleaflet available from Chemetall.For more details please refer tothe chemical literature.

Because of the importance of lith-ium aluminium hydride it isdescribed in detail in a separatespecial brochure which is alsoavailable from Chemetall.

Additional information is availablefrom Chemetall through our prod-uct data sheets, MSDS, as well asour brochure on packaging.

Visit also our website:www.chemetalllithium.com forfurther information and updates.

Metal Hydrides

1 Peter Rittmeyer, Ulrich Wietelmann, Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag, Weinheim 2002

In general they are not used asreducing agents but as a strongbase instead. Another applicationis their capability to store hydro-gen. As a consequence they areused to manufacture furthercomplex metal hydrides. Chemet-all supplies these hydrides inindustrial quantities.

The following products availablefrom Chemetall are described inthis brochure:

Lithium Hydride and SodiumHydride both form ionic hydridesbecause of the strong electro-positive character of the cation.

4

Metal Hydrides

2. Products

Product

Lithium hydride

Sodium hydride

Lithium borohydride

Sodium borohydride

Potassium borohydride

Lithium aluminumhydride (LAH)

Lithium triethylboro –hydride (LTEBH)

Sodium triacetoxyboro-hydride (STAB)

Lithium tri-(t-butoxy)alu-minum hydride(LTTBA)

Availability

Powder

Sieved

Dispersion, abt. 60 % in mineral oil

Solution, 5 % in THF

Powder

Granular

Powder

Powder

Tablets

THF, abt. 4 %

THF, abt. 10 %

2-MeTHF, abt. 10 %

THF/toluene, abt. 15 %

Diethyl ether, abt. 20 %

THF, abt. 12 %

THF, abt. 20 %

Powder

Tablets

Powder

THF, abt. 30 %

Product No.

401613

401606

408164

401652

401251

401254

401666

401614

401616

401625

401634

401632

401630

401631

401749

401729

401667401668

401620

401624

Conc. abt. [%]

min. 97

min 97

57 - 63

4.5 – 5.5

min. 98

min. 98

min. 98

min. 97

min. 97

3.9-4.5

9.5 – 10.5

9.5 – 10.5

14.5 – 15.5

18.0 – 22.0

11.0 – 13.0

19.0 – 21.0

min. 97min. 97

95 – 110

29.0 – 31.0

Density abt.[g/cm3]

0.78

0.78

0.89

1.074

1.074

1.175

0.9

0.9

0.90

0.90

0.87

0.89

0.76

0.89

0.89

0.90

Bulk den-sity abt. [kg/l]

0.29

0.43

0.60

0.4 - 0.5

0.4 – 0.5

0.4

0.4

0.35

0.5

MolarityAbt.

-

-

-

abt. 2

-

-

-

-

-

abt. 1

abt. 2.4

abt. 2.2

abt. 3.5

abt. 4

abt. 1

abt. 1.6

abt. 1.05

Table 1

2.1 Alkali Hydrides - Lithium Hydride and

Sodium Hydride

5

Lithium hydride is available fromChemetall in solid form as amilled powder (grain size < 100µm) or as sieved granulate with agrain size of 3 -25 mm. Theappearance of the granulate islight grey to blue whereas thepowder is grey to white. Lithiumhydride is thermally very stablewith a melting point of 688 °Cwithout decomposition. It hasthe highest hydrogen content ofany alkaline hydride (theor. 12.7%). Lithium hydride is used inlimited quantities for the manu-facture of high purity monosilaneand as hydrogen source for vari-ous purposes. To date the largestapplication remains as a rawmaterial for the manufacture oflithium aluminum hydride (see2.3) and other complex hydrides.A detailed description of thepackaging is given in chapter 4.

Sodium hydride is used commer-cially as a strong base for depro-tonation reactions. It can be usedfor condensation reactions of car-bonyl compounds like Claisen,Dieckmann, Stobbe etc. Further-more it serves as starting materialfor the production of sodiumborohydride (see 2.2.2). Sodiumhydride is a poor reducing agentbecause of its high basicity and itsinsolubility in inert organic sol-vents. Because of it’s properties,i.e. spontaneous ignition of thepure material in humid air it iscommercially available only as aca 60 % dispersion in mineral oil.The particle size of abt. 10 µmleads to a highly reactive materialwhich must be handled under theexclusion of air. Therefore sodiumhydride is packed in solvent solu-ble bags (either soluble in tolueneor in Chemetall’s Secubag). Formore details see 4. Packaging.

The three species of binaryhydrides of boron - Lithium boro-hydride, sodium borohydride,potassium borohydride – are usedon different industrial scales.Whereas sodium borohydride ismanufactured on a multi thou-sand tons scale, the other two

representatives are used to amuch smaller extent only. Theirreaction behavior is stronglydepending on the cation. This canbe seen in the decreasing stability,i.e. decreasing reactivity from Li >Na > K.

2.1.1 Lithium Hydride

CAS No. 7580-67-8

EINECS No. 231-484-3

Molecular weight 7.95

Product no. lithium hydride 401613powder (< 100 µm)

Product no. lithium hydride 401606sieved (3-25 mm)

Appearance bluish to gray grains, white to grey powder

Density 0.78 g/cm3

Bulk density approx. 0.29 kg/l (powder)approx. 0.43 kg/l (grains)

Specification LiH min. 97 %Na max. 0.8 %K max. 0.04 %

Properties of lithium hydride

CAS No. 7646-69-7



Product no. Sodium hydride dis- 408164persion, abt. 60 % in mineral oil

Appearance light gray, tacky powder

Density 1.396 g/cm3

Bulk density Approx. 0.6 kg/l

Specification NaH 57-63%

Properties of sodium hydride

2.1.2 Sodium Hydride

2.2 Binary Hydrides of Boron – Lithium Borohydride, Sodium Borohydride, Potassium Borohydride

6

Lithium borohydride has one ofthe highest energy densities ofchemical carriers. However theproposed use as rocket fuelremains only academic. It is usedfor the selective reductions ofesters, carboxylic acids, amidesand epoxides. The addition of astoichiometric amount of alco-hols (methanol or ethanol) con-siderably enhances the reactivity.Because of the extreme hygro-scopicity of solid lithium boro-hydride it is currently only avail-able as a 5 % (2 m) solution inTHF. Packaging is described inchapter 4.

Sodium borohydride is by far themost commonly used species ofthe borohydrides group. Sodiumborohydride is manufacturedmainly for bleaching of pulp andpaper on a several thousandtons scale as a 12 % alkalineaqueous solution (for the in situproduction of sodium dithio-nite). The solid form is used as aversatile reducing agent in theorganic chemical and pharma-ceutical industry. For packagingdetails please refer to chapter 4.

Nucleophilicity decreases in the order LiBH4 > NaBH4 > KBH4

Melting pointDecomposition

LiBH4

280 °C

> 200 °C

NaBH4

505 °C

>400 °C

KBH4

585°C

> 500°C

2.2.1 Lithium Borohydride

2.2.2 Sodium Borohydride

CAS No. 16949-15-8



Product no. lithium borohydride, 401652abt. 5 % in THF

Appearance colorless, slightly turbid solution

Density (20 °C) 0.89 g/cm3

Specification 4.5 – 5.5 %

Molarity 1.8 – 2.2

Properties of lithium borohydride solution, abt. 5 % in THF

CAS No. 16940-66-2



Product no. sodium borohydride, 408254granular

Product no. sodium borohydride, 408251powder

Appearance white granulate or white, slightly hygroscopic powder

Density 1.074 g/cm3

Bulk density 0.4 – 0.5 kg/l

Grain size granulate 0.5 – 2.0 mm

Specification Min. 97 %

NaH Max. 0.5 %

H2O Max. 0.5 %

Properties of sodium borohydride

7

Lithium Aluminum Hydride (LAH)is the strongest reducing agentand is widely used in organic andpharmaceutical synthesis. Due tothe weaker Al-H bond it is a muchmore powerful reducing agentthan sodium borohydride. It ismost commonly used for thereduction of e.g. esters and car-boxylic acids. Because of it’s impor-tance and the flexibility in han-dling, lithium aluminum hydride isdescribed in greater detail in aseparate brochure which is avail-able from Chemetall. The follow-ing is only a summary of theimportant points. For packagingdetails see chapter 4 or the dedi-cated brochure on LAH.

2.2.3 Potassium Borohydride CAS No. 13762-51-1



Product no. potassium 401666borohydride

Appearance white, crystalline powder

Density 1.175 g/cm3

Specification min. 98 %

Properties of potassium borohydride

Product no. lithium aluminum 401614hydride, crystalline powder

Product no. lithium aluminum 401616hydride, tablets

Appearance white to light grey

Density 0.917 g/cm3

Bulk density abt. 0.4 kg/l


Solid LAH

2.3 Binary Hydrides of Aluminum – Lithium

Aluminum Hydride (LAH)

CAS No. 16853-85-3



Properties of lithium aluminum hydride

Potassium borohydride is com-pletely stable in air and not hygro-scopic. The hydrolysation reactionin humid air is extremely slow. Thesolubility compared to the otherbinary borohydrides is much lower.The reactivity is slightly lower com-pared to sodium borohydride butit is much less used as a reducingagent in organic and pharmaceuti-cal chemistries. It can be used forthe chemoselective reduction ofaldehydes, ketones, acid chlorides,or azides. Packaging is describedin chapter 4.

8

2.4 Complex Hydrides ofLithium and Boron –Lithium Triethylboro-

hydride (LTEBH)

Lithium triethylborohydride, alsoknown under the brand nameSuper-Hydride® is one of the morefrequently used alkyl substitutedcomplex borohydrides. It is com-mercially available as a 12 % (1 m)or as a 20 % solution in THF and isstable under the exclusion ofhumidity and air. It is a stereose-lective reducing agent for e.g.bicyclic imides, isoquinolines, andpyridines. Packaging is describedin chapter 4.

CAS No. 22560-16-3



Product no. lithium 401749triethylborohydride, abt. 12 % solution in THF

Product no. lithium 401729triethylborohydride, abt. 20 % solution in THF

Appearance colorless to light turbid solution

Density (20 °C) 0.89 g/cm3

Specification 11 – 13 % resp. 19-21 %

Properties of lithium triethylborohydride

Product

LAH, abt. 4 % in THF

LAH, abt. 10 % in THF

LAH, abt. 10 % in 2-MethylTHF

LAH, 15 % in THF/toluene

LAH, 20 % in diethyl ether

Product no.

401625

401634

401632

401630

401631

Concentration

3.9 – 4.5 %

9.5 –10.5 %

9.5 – 10.5 %

14.5 – 15.5 %

18.0 – 22.0 %

Density abt. [20°C]

0.9 g/cm3

0.9 g/cm3

0.87 g/cm3

0.89 g/cm3

0.76 g/cm3

Molarity abt.

1

2.4

2.4

3.5

4.0

LAH solutions

9

Lithium tri(t-butoxy)aluminumhydride (LTTBA) is a milderreducing agent than the non-substituted LAH. Therefore it isalso more stable (sublimation at280 °C) and decomposes at >300 °C only. It is very suitablefor the selective reduction ofketones or acid chlorides toaldehydes whereas LAH reducesto the corresponding alcohol.It is available as white crys-talline powder or as a 30% solu-tion in THF. For packagingdetails see chapter 4.

CAS No. 56553-60-7

EINECS No -


Product no. sodium 401667triacetoxyborohydridepowder tablets 401668

Appearance colorless, light, fluffy powder or tablets

Density 0.956 g/cm3

Bulk density approx. 0.35 kg/l


Properties of sodium triacetoxyborohydride

CAS No. 17476-04-9



Product no. lithium tri(t-butoxy) 401624aluminum hydride, solution

Product no. lithium tri(t-butoxy) 401620aluminum hydride, powder

Appearance clear to slightly turbid solutionor white to light grey powder

Density (20 °C) 0.9 g/cm3 solution

Bulk density abt. 0.5 kg/l solid

Specification 29-31 % solution95-110 % solid

Properties of lithium tri-(t-butoxy)aluminum hydride

2.5 Complex Hydrides ofSodium and Boron –

Sodium Triacetoxyboro-hydride (STAB)

2.6 Complex Hydrides ofLithium and Aluminum – Lithium Tri-(t-butoxy)alu-minum Hydride (LTTBA)

Sodium triacetoxyborohydride iscomparable in performance tothe toxic counterpart sodiumcyanoborohydride.

Sodium triacetoxyborohydride(STAB) is a mild reducing agentand an ideal alternative for thetoxic cyanoborohydride. STAB isused for reductive aminations,the reduction of heterocycles,and the selective reduction ofaldehydes in the presence ofketones. Though STAB does notreact with ketones even with anexcess of reagent, it can be usedfor the stereoselective reductionof α- and β-hydroxyketones tothe corresponding anti-diols. STABthus offers a wide range of appli-cations in organic synthesis. Pack-aging is described in chapter 4.

10

The products LAH, LTTBA, LiBH4

and LTEBH are available as readyto use solutions. For laboratoryuse they are available in glass bot-tles of 500 ml and 1 l contentequipped with a special septumand a screw cap.

Safe handling of these solutionsrequires some precautions whichare due to the specific propertiesof complex metal hydrides.

■ Do not expose solutions in glassbottles to temperatures aboveroom temperature and lightirradiation for extended periodsof time

■ Do not use wet syringes forsampling. Residues of water orother protic substances willreact with the hydride withevolution of gas.

■ Do not store hydride solutionsfor more than 6 months. It isrecommended to use a bottlewithin 3 months (see label onglass bottle with date of pro-duction).

■ Store the solutions protectedfrom light and heat, preferablyin an explosion-proof refrigera-tor or a safety cabinet

Commercially available hydridesare normally non-pyrophoric,even on exposure to air withhigh humidity. However the for-mation of dust/hydrogen/air-mix-tures has to be strictly avoided as

these are dangerous and mayeasily explode. Therefore the sol-vent soluble bags containing e.g.LiAlH4-powder or NaH should notbe opened in air. If LiAlH4 in solidform must be handled in air, theuse of LiAlH4-tablets is recom-mended instead. The solid boro-hydrides are less sensitivetowards air.All hydrides are hygroscopic and,due to their reaction with atmos-pheric moisture and carbon diox-ide, will degrade when exposed tohumid air. On contact with dry air,they will also lose activity, but at amuch slower rate.

Spilled solutions of hydrides nor-mally do not ignite as they areprotected by the formation of ahydroxide-layer on their surface.Nevertheless self-ignition cannotbe ruled out. An increase in therisk of self-ignition will result ifethereal solutions of LAH, LTTBA,LiBH4 or LiBEt3H are spilled ontoa porous surface (e. g. clothing).Rapid evaporation of the solventleads to the formation of a veryfinely divided hydride. In such acase, self-ignition might easilyoccur.

All hydrides react with water gen-erating highly flammable hydro-gen gas. The borohydrides, espe-cially NaBH4 and KBH4 decomposeonly slowly in water, especially inalkaline solutions. On the otherhand products like LAH, LiH, NaHreact violently with water. Thelarge amount of hydrogen formedin this reaction (e.g. 2.36 l H2/gLiAlH4) is highly flammable andcan form explosive mixtures withair. Under certain conditions, e. g.when water is sprayed on LiAlH4in the presence of air, the hydro-gen will ignite spontaneously.

Eliminating accidental contactwith water should, therefore, be aprimary concern when handlingor storing hydrides.

If hydride powders must be han-dled in air by opening the solubleinner bags, special care has to betaken: The formation of dust mustbe avoided as an ignition sourcesuch as a spark from an electro-static discharge could easily causea dust explosion. Therefore allequipment which is used in han-dling hydrides should be of stainless steel, copper or zincinstead of glass, plastic or iron.Extreme caution should be exercised when the hygroscopicLiAlH4 comes in contact with air.The resulting mixture is rich inhydrogen and prone to ignition by static discharge.

Handling larger amounts ofhydrides, especially LiAlH4- pow-der in air is not at all recom-mended.

If it is essential to open the bagscontaining hydride powders, thiscan be done without risk underinert gas in a glove-box. Theglove-box should be operatedunder a slight overpressure ofsome mbar of nitrogen or argon.

Fires of solid hydrides or theirsolutions should be fought withsuitable extinguishers containingpowder based on sodium chloride(e.g. Totalit M ®). Dry limestonepowder is also suitable and shouldbe kept in boxes close to the areawhere the products are used. (seeFig. 1) The limestone powder canbe used not only to cover spilledsolutions but also to cover burning

Metal Hydrides

3.1 Storage

3.3 Reaction with Water

3.1.1 Storage in the Laboratory

3.2 Behavior of Hydridestowards Air

3.4 Handling of SolidHydrides

3. Safe Handling

3.5 Fire Fighting

11

hydrides. Due to its poor flowingproperties, it is not available inextinguishers. Sand is not suitableto cover spilled solutions.

Extinguishers containing or devel-oping water, carbon dioxide orhalons are not suitable for firefighting as they react violentlywith the hydrides.

Extinguished fires should beobserved until they have cooleddown as there is always the risk ofre-ignition.

To ensure safe performance of thereduction with hydrides, operatingpersonnel should be properlytrained, instructed and informedof potential dangers and the cor-rect action to be taken in case ofspillage or an accident.

Operating personnel should wearadequate protective equipment(see figure 2). This includes:

Protective clothing

Chemetall personnel wear pro-tective suits from Nomex® whichhas proven to be very satisfac-tory. For occasional contact withhydrides protective coats fromNomex® with an aluminum layerare also suitable. The protectiveclothing should not have outsidepockets where solution couldbecome trapped. Clothing andunderclothing made from othersynthetic fibers should not beworn because of the possibilityof melting when exposed to fire.This safety measure is required inany case since inflammableorganic solvents will be used.Cotton overalls or coats are notsuitable.

Gloves

Dry and clean Nomex® gloves servefor protection of the hands. Rub-ber gloves are not suitable.

Eye/Face protection

Goggles and / or full face shieldsare mandatory.

Dust mask

If it is absolutely necessary to openbags in air, operators should weardust proof masks.

Shoes

To prevent the possibility of elec-trostatic discharges, personnel

should wear safety shoes with con-ductive soles (maximum resistance800 K�).

In the event product comes incontact with the skin, it must bebrushed off immediately andrinsed with plenty of runningwater until no traces of alkalinityare detectable with indicatorpaper.

If the eyes have been exposed tohydrides, they should be thor-oughly rinsed with plenty ofwater. A physician should then beconsulted immediately

3.6 Protection of Personnel

Fig. 1 Fire-fighting equipment

3.7 First Aid

12

For disposal of small amounts ofsolid hydride waste, the materialshould first be covered with ahigh-boiling hydrocarbon suchas thermal oil or toluene. Thenethanol or iso-propanol is addedcarefully while stirring, pref-erably with cooling, under nitro-gen blanketing. After the hydro-gen evolution is complete, theagitated alkoxide sludge ishydrolyzed with water andflushed to the plant's wastewater treatment facilities.

For disposal of hydride solutions,the procedure is the same,except that the addition of

hydrocarbons is omitted if thesolution is already sufficientlydiluted. Any spill of solutionshould be covered with lime-stone or another suitable extin-guishing powder. The soakedmaterial should then be taken toa safe outdoor place and bedecomposed by standing in airfor some days or from a safe dis-tance by a jet of water.

The hydrolysis requires an inertgas blanket or, in the event of anemergency, adequate ventilationmust be provided to prevent for-mation of explosive hydrogen-airmixtures.

For the disposal of large amountsof hydrides Chemetall should becontacted

Fig. 2 Protective Clothing (Nomex®

Suit)

3.8 Disposal of Residues

13

Packaging can be made accord-ing to the customer’s needs. Incase of solid products packagingin units up to 10 kg (LiH, NaH,LAH and LTTBA 5 kg) per bag are

Metal Hydrides

4. Packaging and Transport

4.1 Solid Products

Product

LiH

NaH

NaBH4

KBH4

LAH

STAB

LTTBA

Standard packaging

5 kg PE

5 kg SecuBag

10 kg PE bag

10 kg PE bag

5 kg SecuBag

1.000 ml glass bottle

5 kg SecuBag

Remarks

Development product

possible – even odd weights canbe made.

Standard packaging for solidhydrides is as follows:

Hydrides are usually doublepacked in plastic bags which arethen enclosed either in tin cansor for larger quantities, in steeldrums. Standard sizes are bagscontaining 10 g, 25 g, 50 g, 100g, 250 g, 500 g and 1.000 g in tincans as well as 2.000 g and 5.000g in steel drums. The inner plasticbag, which is normally heat

The aforementioned SecuBagsare solvent soluble plastic bagswhich allow the material beingintroduced into the reactor with-out opening the bag and/or con-tact with air.

In the following table the solu-tion behavior of the Secubags isdescribed.

Solvent

Hexane

Heptane

Cyclohexane

Toluene

Diethyl ether

MTBE

THF

2-Methyl-THF

Monoglyme

Dimethylacetamide

DMF

Appearance of solution at 25 °C

Bigger parts (turbid at 60 °C)

Bigger parts (clear at 60 °C)

Clear

Clear

Turbid

Clear

Clear

Clear

Clear

Turbid

Turbid

Results

±

±

+

+

+

+

+

+

+

+

+

sealed, is Chemetall’s solvent solu-ble SecuBag ® except for lithiumhydride and the borohydrideswhich are packed in PE bags. Theouter bag, which is normallyclipped, is a normal PE bag whichdoes not dissolve in solvents.

On request Chemetall is readilyprepared to pack solid hydridesaccording to the customer'sneed, e. g. odd weights per bagor several bags per can or drum.

This special packaging enables theusers to introduce the hydridedirectly into the reactor withoutexposing it to air. Inside each canor steel drum, used as the outerpackaging for the hydride, a tag isenclosed indicating safety adviceand the nature of the inner, solu-ble bag. A special case is LAH andSTAB which are also available astablets. For more details please seethe LAH brochure.

The following table shows theproperties of various solvents com-mercially used

14

Some of the hydrides are alsoavailable in solution form. Forthis purpose Chemetall uses spe-cial returnable steel-cylinderswhich are described in a separatebrochure.

The solutions are available in fourdifferent sizes of steel cylinderswith the following maximum con-tents of active product

Solvent

THF

2-Methyl-THF

Toluene

Xylene

Di-ethyl ether

Di-isopropyl ether

Di n-butyl ether

MTBE

Dioxane

mp °C

-65

-136

-95

-25

-116

-86

-98

-109

12

bp °C

65

78

110

114

34.6

69

142

55

101

Physical constants Density solventg/ml

0.888

0.860

0.867

0.880

0.713

0.724

0.772

0.740

1.034

4.2 Products in SolutionDue to international transporta-tion regulations, the cylinders arefilled to only 90 %of their nomi-nal capacity. Inside the cylinders isa nitrogen blanket with a slightoverpressure of 20 - 40 mbar.

On request the cylinders can befilled with any desired amount ofsolution defined by the user (upto the maximum as indicatedabove). Therefore the hydridecontent can be adjusted to theindividual size of the productionbatch.

Product

LAH 4 % THF

LAH 10 % THF

LAH 10 % in 2-MeTHF

LAH 15 % THF/toluene

LAH 20 % in DEE

LTEBH 12 %

LTEBH 20 %

LTTBA 30 % THF

1 l glass bottle

0.03

0.08

0.08

0.12

0.14

0.09

0.17

0.24

5 l

0.16

0.36

0.36

0.58

0.61

0.49

0.85

1.22

40 l

1.3

3.0

3.0

4.6

4.9

3.5

6.1

8.7

125 l

4.0

9.6

9.6

14.5

15.4

11.0

19.0

27.3

450 l

14.2

34.6

34.6

52.2

55.3

39.6

68.5

98.4

Max content per cylinder (kg active)

Samples of hydrides in solutionform are sent either in glass bot-tles of 500 ml or 1 l or in return-able steel cylinders which containup to 5 l solution. Those steelcylinders are emptied by a diptube. The description is availableon request. Storage of the glassbottles in the lab is described inchapter 3.2.1.

All cylinders sizes have the sametype number and arrangement ofvalves

15

Detailed and up-dated transport regulations is available in the corresponding MSDSs which are availablefrom Chemetall.

Product

Lithium hydride

Sodium Hydride

Lithium borohydride, 5 % in THF

Sodium borohydride


Lithium aluminum hydride, solid

Lithium aluminumhydride solutions

Lithium triethylborohydride

Sodium triacetoxyborohydride

Lithium tri-(t-butoxy)aluminum hydride, solid

Lithium tri-(t-butoxy)alu-minum hydride, solution

UN No.

1414

1427

1413

1426

1870

1410

1411

3394

3238

1409

3399

PSN

Lithium Hydride

Sodium hydride

Lithium borohydride

Sodium borohydride


Lithium aluminum hydride

Lithium aluminum hydride, ethereal

Organometallic substance, liquid, water-reactive, Lithium triethylborohydride,tetrahydrofurane

Self reactive solid, Type E, temperature controlled

Metal hydrides, water-reactive, n.o.s., lithiumtri-(tert.butoxy) aluminium hydride

Organometallic substance, liquid, waterreactive, flammable Lithium-tri-(tert-butoxy)-aluminium hydride, tetrahydrofuran

Class

4.3

4.3

4.3

4.3

4.3

4.3

4.3

4.2

4.1

4.3

4.3

Marking

F, C

F

F, C

T, F

T, F

F, C

F, C

F, C

F, C

F, C

F, C

Hydrides are classified accordingto international regulations inthe following :

Metal Hydrides

5. Transport

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Fig. 3

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Principle: Solid hydrides aredecomposed by aqueous dioxaneand the hydrogen thereby pro-duced is measured volumetrically.

Apparatus: see fig. 3

Procedure: 0.1 g of the materialto be analyzed is weighed in adry weighing glass to an accuracyof 0.1 mg which is then attachedto the hydrolyzing apparatus.Through the dropping funnel 2ml of dioxane is added followedby 10 ml of water, which hasbeen acidified with about 0.5 mlof conc. hydrochloric acid. Thisaddition should initially proceeddropwise in order to avoid too avigorous reaction. Hydrogen iscollected in the gas burette oversaturated sodium chloride solu-tion. After temperature equilib-rium has been established, thehydride content of the samplemay be calculated from the gasvolume reading according to thefollowing equation:

F: FactorV: hydrogen volume [ml] Pcorr.: (atmospheric pressure) -

(vapor pressure of sat.NaCl-solution at measuring temperature)[mm Hg]

T: measuring temperature [K] M: mass of sample [g]

Vapor pressure of a saturated NaCl solution

For the various hydrides the following factors apply:

Metal Hydrides

6. Analysis

6.1 Analysis of SolidHydrides

V · Pcorr.wt % Hydride = F ·

T · M

°C 15 16 17 18 19 20 21 22 23 24 25 26

mm 9.7 10.3 11.0 11.7 12.4 13.2 14.1 15.0 15.9 16.9 17.9 19.0Hg

LiH 0.01273 LiAlH4 0.01521

NaH 0.03846 LTEBH 0.16981

LiBH4 0.008729 STAB 0.33987

NaBH4 0.01516 LTTBA 0.4077

KBH4 0.02162

The following description is forLAH solution only – the otherhydride solutions are measuredaccording to 6.1

Principle: Solutions of LiAlH4

react stoichiometrically with solu-tions of iodine in toluene (pro-vided that the concentration ofLiAlH4 in the reaction mixture isbetween 0,1 and 1,0 M) consum-ing four equivalents of iodine permole of LiAlH4. Hydrogen isevolved simultaneously (Felkin'smethod)2: Reagents and equipment: Diethyl ether, distilled over LiAlH4

Toluene, distilled over LiAlH4

0.4 n Solution of iodine intoluene n Sodium thiosulphate solution(standardized with KIO3) Glacial acetic acid Zinc iodide / starch solution 250 ml Titrating flask withground glass joint NS 29 20 ml and 1 ml Pipettes 5 ml Syringe with needle andstopcock dried at 110 °C 10 ml Graduated cylinder 50 ml Burette with 0.1 ml gradua-tion

Procedure: 20 ml of 0.4 n solu-tion of iodine in toluene is intro-duced into the dried titratingflask. When analyzing solutionsof lithium aluminum hydride inother solvents than diethyl ether,1 ml of diethyl ether is added. Asample of LiAlH4 solution whichshould contain about 1 mmolLiAlH4 is weighed in the driedsyringe. The syringe is then intro-duced into the titrating flask andits contents are emptied throughthe submerged needle into theiodine solution under gentle agi-tation. Allow to stand for 5 min-utes, then quickly add 100 ml ofdistilled water and 5 ml of glacialacetic. Excess iodine is titratedwith 0.1 n solution of sodiumthiosulphate, using zinc iodide/starch solution as indicator.

Evaluation:

M: mass of sample [g] C: consumption of 0.4 n iodine

solution [ml] = (initial amountof 0.4 iodine solution in ml) -0.25 - (consumption of 0.1 nthiosulphate solution in ml)

Note: Standard solutions ofiodine in toluene are not stableand should, therefore, be re-stan-dardized prior to use.

6.2 Analysis of LAH Solutions

LiAlH4 + 2l2 2 H2 + LiAll4

C% LiAlH4 = 0.37953 ·

M

2 H. Felkin, Bull. Soc. Chim. France, 1951, 347.

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DDiissccllaaiimmeerrThe above product information has been compiled to the best of our knowledge on the basis of thoroughtests and with regard to the current state of our long practical experience. Our statements relating to possible uses of the product do not constitute a guarantee that such uses are appropriate in a particularuser’s case or that such uses do not infringe the patents or proprietary rights of any third party. The usershould determine the suitability of the product for the user’s intended use before commencing such use. Weassume no risk or liability whatever in connection with any particular use, if not expressly confirmed by us inwriting. No liabilities or guarantees deriving from or in connection with this brochure can be imputed to us.

WARRANTY & LIABILITY: In the event our product does not conform to the specifications described in thisbrochure the purchaser’s sole and exclusive remedy shall be either the replacement by us of that portion ofthe product which is non-conforming or the refund by us of the purchase price for the non-conforming portion, in our sole discretion as we may select.

The foregoing is our sole warranty in regard to the product: ALL OTHER WARRANTIES, EXPRESS ORIMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, AREEXCLUDED. We shall not under any circumstances be liable, either directly or by way of indemnification orcontribution, to any person for any direct, indirect, special or consequential damages arising out of the purchase or use of the product, whether the claim of such liability sounds in contract, tort or otherwise;except in case of wilful misconduct.

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Further information regarding this type of reagent and its reactions can befound in our dedicated pocket folders.

Please don’t hesitate to ask for your copy.

Europe

Chemetall GmbH

Lithium Division

Trakehner Straße 3

D-60487 Frankfurt am Main

Phone +49 69 7165-2554

Fax +49 69 7165-2053

E-mail [email protected]

Americas

Chemetall Foote Corp.

348 Holiday Inn Drive

Kings Mountain,

North Carolina 28086

Phone +1 704 739-2501

Fax +1 704 734-2718


www.chemetalllithium.com

Asia

Chemetall Taiwan Co., Ltd.

No 2, Hsien-Kon N. First Road

Chang Bin Industrial Park

Hsien Si, Chang Hua County, Taiwan

Phone +886 4 758-5016

Fax +886 4 758-6415


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DL Metal Hydrides