Hafnium Bromide is a highly water soluble crystalline Hafnium source for uses compatible with Bromides and lower (acidic) pH. Metallic Bromides are marketed under the trade name AE Bromides™. Most metal bromide compounds are water soluble for uses in water treatment, chemical analysis and in ultra high purity for certain crystal growth applications. Bromide in an aqueous solution can be detected by adding carbon disulfide (CS2) and chlorine.
Hafnium Bromide is generally immediately available in most volumes. Ultra high purity and high purity compositions improve both optical quality and usefulness as scientific standards. Nanoscale (See also Nanotechnology Information and Quantum Dots) elemental powders and suspensions, as alternative high surface area forms, may be considered.American Elements produces to many standard grades when applicable, including Mil Spec (military grade); ACS, Reagent and Technical Grade; Food, Agricultural and Pharmaceutical Grade; Optical Grade, USP and EP/BP (European Pharmacopoeia/British Pharmacopoeia)and follows applicable ASTM testing standards.Typical and custom packaging is available. Additional technical, research and safety (MSDS) information is available as is a Reference Calculator for converting relevant units of measurement.
Hafnium is a Block D, Group 4, Period 6 element. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electronic configuration is [Xe] 4f14 5d2 6s2. In its elemental form hafnium's CAS number is 7440-58-6.The hafnium atom has a radius of 156.4.pm and it's Van der Waals radius is 200.pm. Hafnium is not toxic. Hafnium is one of the Group IV transition elements that is refined from various zirconic mineral deposits. Hafnium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder. It's primary uses are due to its ability as a nuclear "getter" or absorber of neutrons. It is a primary component in nuclear control rods for this purpose. It also finds uses as a dopant in the alloy of steel and titanium. It is also used in the production of mantles for high intensity incandescent lamps. Hafnium is replacing polysilicon as the principle gate or electrode material in metaloxide semiconductor field effect transistors (MOSFETs) which are the basis for all modern semiconductors. As semiconductors have gotten smaller, the limiting factor in further size reduction has been the ability of the silicon oxide gate to perform below 10 angstroms where leakage occurs. Recent research has been devoted to the development of High-k materials which can function as a di-electric barrier or gate with lower leakage. Using hafnium based alloys as this di-electric gate has allowed for the development of MOSFET gates smaller than 10 angstroms. This allows for further size reduction, reduced switching power requirements and improved performance. Hafnium was first discovered by Dirk Coster in 1923. See Hafnium research below.
N(2) Activation by a Hafnium Complex: A DFT
Study on CO-Assisted Dinitrogen Cleavage and Functionalization. Zhang X, Butschke B, Schwarz H. Chemistry. 2010
Sep 28. [Epub ahead of print] PubMed PMID: 20878807.
Effective enrichment and mass spectrometry analysis of phosphopeptides using
mesoporous metal oxide nanomaterials. Nelson CA, Szczech JR, Dooley CJ, Xu Q, Lawrence MJ, Zhu H, Jin S, Ge Y. Anal Chem. 2010 Sep 1;82(17):7193-201.
PubMed PMID: 20704311; PubMed Central PMCID: PMC2936271.
Synthesis, characterization and
biological study on Cr(3+), ZrO(2+), HfO(2+) and UO(2)(2+) complexes of
oxalohydrazide and bis(3-hydroxyimino)butan-2-ylidene)-oxalohydrazide.
El-Asmy AA, El-Gammal OA, Radwan HA. Spectrochim Acta A Mol Biomol Spectrosc. 2010 Sep 1;76(5):496-501. Epub 2010 Apr
21. PubMed PMID: 20451440.
Intramolecular
sigma-bond metathesis/protonolysis on zirconium(IV) and hafnium(IV) pyridylamido
olefin polymerization catalyst precursors: exploring unexpected reactivity paths.
Luconi L, Giambastiani G, Rossin A, Bianchini C, Lledós A. Inorg Chem. 2010 Aug 2;49(15):6811-3. PubMed PMID: 20583749.
Guided-mode resonant wave plates.
Magnusson R, Shokooh-Saremi M, Johnson EG. Opt Lett. 2010 Jul 15;35(14):2472-4. doi: 10.1364/OL.35.002472. PubMed PMID:
20634867.
Initiation of a
passivated interface between hafnium oxide and In(Ga)As(0 0 1)-(4x2). Clemens JB, Bishop SR, Lee JS, Kummel AC, Droopad R. J Chem
Phys. 2010 Jun 28;132(24):244701. PubMed PMID: 20590208.
Zirconium(IV)- and hafnium(IV)-catalyzed highly
enantioselective epoxidation of homoallylic and bishomoallylic alcohols. Li Z, Yamamoto H. J Am
Chem Soc. 2010 Jun 16;132(23):7878-80. PubMed PMID: 20481541; PubMed Central
PMCID: PMC2886809.
Combined U-Pb and Lu-Hf isotope
analyses by laser ablation MC-ICP-MS: methodology and applications. Matteini M, Dantas EL, Pimentel MM, Bühn B. An Acad Bras
Cienc. 2010 Jun;82(2):479-91. PubMed PMID: 20563428.
Preparation and structures of
enantiomeric dinuclear zirconium and hafnium complexes containing two homochiral
N atoms, and their catalytic property for polymerization of rac-lactide. Hu M, Wang M, Zhu H, Zhang L, Zhang H, Sun L. Dalton
Trans. 2010 May 14;39(18):4440-6. Epub 2010 Mar 31. PubMed PMID: 20358041.
Effect of deposition temperature on the
characteristics of HfN(x) thin films prepared by plasma assisted cyclic chemical
vapor deposition. Kim EJ, Woo HG, Kim DH. J Nanosci Nanotechnol. 2010 May;10(5):3463-6. PubMed PMID:
20358979.
A younger age for ALH84001 and its geochemical link to shergottite sources in
Mars. Lapen TJ, Righter M, Brandon AD, Debaille V, Beard BL, Shafer JT, Peslier AH. Science. 2010 Apr 16;328(5976):347-51. PubMed PMID: 20395507.
Improved reliability from a
plasma-assisted metal-insulator-metal capacitor comprising a high-k HfO2 film on
a flexible polyimide substrate. Meena JS, Chu MC, Kuo SW, Chang FC, Ko FH. Phys Chem Chem Phys. 2010 Mar 20;12(11):2582-9.
Epub 2010 Jan 26. PubMed PMID: 20200734.
Optical coatings in microscale channels by atomic
layer deposition. Gabriel NT, Talghader JJ. Appl Opt. 2010 Mar 10;49(8):1242-8. doi: 10.1364/AO.49.001242.
PubMed PMID: 20220879.
Effect of
TiF4, ZrF4, HfF4 and AmF on erosion and erosion/abrasion of enamel and dentin in
situ. Wiegand A, Hiestand B, Sener B, Magalhães AC, Roos M, Attin T. Arch Oral Biol. 2010 Mar;55(3):223-8. Epub 2010 Jan 18. PubMed PMID:
20083245.
Hydrolysis of
bis(p-nitrophenyl)phosphate by tetravalent metal complexes with Klaui's oxygen
tripodal ligand. Yi XY, Lam TC, Williams ID, Leung WH. Inorg Chem. 2010 Mar 1;49(5):2232-8. PubMed PMID: 20131806.
Synthesis of nested coaxial
multiple-walled nanotubes by atomic layer deposition. Gu D, Baumgart H, Abdel-Fattah TM, Namkoong G. ACS Nano. 2010 Feb
23;4(2):753-8. Erratum in: ACS Nano. 2010 Jul 27;4(7):4331. PubMed PMID:
20085347.
Synthesis and characterisation of ionic liquids based on
1-butyl-3-methylimidazolium chloride and MCl(4), M = Hf and Zr. Campbell PS, Santini CC, Bouchu D, Fenet B, Rycerz L, Chauvin Y, Gaune-Escard
M, Bessada C, Rollet AL. Dalton Trans.
2010 Feb 7;39(5):1379-88. Epub 2009 Dec 1. PubMed PMID: 20104366.
Dielectric
surface-controlled low-voltage organic transistors via n-alkyl phosphonic acid
self-assembled monolayers on high-k metal oxide. Acton BO, Ting GG, Shamberger PJ, Ohuchi FS, Ma H, Jen AK. ACS Appl Mater Interfaces. 2010
Feb;2(2):511-20. PubMed PMID: 20356199.
In situ reaction
mechanism studies on ozone-based atomic layer deposition of Al(2)O(3) and HfO(2). Rose M, Niinistö J, Endler I, Bartha JW, Kücher P, Ritala M.
ACS Appl Mater Interfaces. 2010 Feb;2(2):347-50. PubMed PMID: 20356179.
Is titanium tetrafluoride (TiF4) effective
to prevent carious and erosive lesions? A review of the literature. Wiegand A, Magalhães AC, Attin T. Oral Health
Prev Dent. 2010;8(2):159-64. Review. PubMed PMID: 20589250.
Synthesis of Enol Lactones via Cu(I)-Catalyzed Intramolecular O-Vinylation of Carboxylic Acids.
Sun C, Fang Y, Li S, Zhang Y, Zhao Q, Zhu S, Li C.
Org Lett. 2010 Jan 5. [Epub ahead of print]
PMID: 19689116 [PubMed - as supplied by publisher]
Formation of ArF from LPdAr(F): Catalytic Conversion of Aryl Triflates to Aryl Fluorides.
Watson DA, Su M, Teverovskiy G, Zhang Y, García-Fortanet J, Kinzel T, Buchwald SL.
Science. 2009 Aug 13. [Epub ahead of print]
PMID: 19679769 [PubMed - as supplied by publisher]
(2-Pyridyl)acetone-Promoted Cu-Catalyzed O-Arylation of Phenols with Aryl Iodides, Bromides, and Chlorides.
Zhang Q, Wang D, Wang X, Ding K.
J Org Chem. 2009 Aug 12. [Epub ahead of print]
PMID: 19673481 [PubMed - as supplied by publisher]
Ni-Catalyzed Sonogashira Coupling of Nonactivated Alkyl Halides: Orthogonal Functionalization of Alkyl Iodides, Bromides, and Chlorides.
Vechorkin O, Barmaz D, Proust V, Hu X.
J Am Chem Soc. 2009 Aug 11. [Epub ahead of print]
PMID: 19670863 [PubMed - as supplied by publisher]
Zn-mediated electrochemical allylation of aldehydes in aqueous ammonia.
Huang JM, Dong Y.
Chem Commun (Camb). 2009 Jul 14;(26):3943-5. Epub 2009 May 28.
PMID: 19662260 [PubMed - in process]
Practical Catalytic Asymmetric Synthesis of Diaryl-, Aryl Heteroaryl-, and Diheteroarylmethanols.
Salvi L, Kim JG, Walsh PJ.
J Am Chem Soc. 2009 Aug 4. [Epub ahead of print]
PMID: 19653691 [PubMed - as supplied by publisher]
Direct Palladium-Catalyzed Arylations of Aryl Bromides with 2/9-Substituted Pyrimido[5,4-b]indolizines.
Jiang M, Li T, Meng L, Yang C, Xie Y, Ding J.
J Comb Chem. 2009 Jul 31. [Epub ahead of print]
PMID: 19645499 [PubMed - as supplied by publisher]
Versatile chemoselectivity in Ni-catalyzed multiple bond carbonylations and cyclocarbonylations in CO(2)-expanded liquids.
del Moral D, Banet Osuna AM, Córdoba A, Moretó JM, Veciana J, Ricart S, Ventosa N.
Chem Commun (Camb). 2009 Aug 21;(31):4723-5. Epub 2009 Jun 29.
PMID: 19641822 [PubMed - in process]
Highly Selective Biaryl Cross-Coupling Reactions between Aryl Halides and Aryl Grignard Reagents: A New Catalyst Combination of N-Heterocyclic Carbenes and Iron, Cobalt, and Nickel Fluorides.
Hatakeyama T, Hashimoto S, Ishizuka K, Nakamura M.
J Am Chem Soc. 2009 Jul 29. [Epub ahead of print]
PMID: 19639999 [PubMed - as supplied by publisher]
Hexacationic Dendriphos Ligands in the Pd-Catalyzed Suzuki-Miyaura Cross-Coupling Reaction: Scope and Mechanistic Studies.
Snelders DJ, van Koten G, Klein Gebbink RJ.
J Am Chem Soc. 2009 Jul 29. [Epub ahead of print]
PMID: 19639941 [PubMed - as supplied by publisher]
Can One Predict Changes from S(N)1 to S(N)2 Mechanisms?
Phan TB, Nolte C, Kobayashi S, Ofial AR, Mayr H.
J Am Chem Soc. 2009 Jul 27. [Epub ahead of print]
PMID: 19634906 [PubMed - as supplied by publisher]
A General Copper-Catalyzed Coupling of Azoles with Vinyl Bromides.
Liao Q, Wang Y, Zhang L, Xi C.
J Org Chem. 2009 Jul 15. [Epub ahead of print]
PMID: 19603753 [PubMed - as supplied by publisher]
Kinetics of Bromine-Magnesium Exchange Reactions in Heteroaryl Bromides.
Shi L, Chu Y, Knochel P, Mayr H.
Org Lett. 2009 Jul 14. [Epub ahead of print]
PMID: 19601592 [PubMed - as supplied by publisher]
C5-Modified nucleosides exhibiting anticancer activity.
Lee YS, Park SM, Kim HM, Park SK, Lee K, Lee CW, Kim BH.
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Palladium-Catalyzed Coupling of Ammonia with Aryl Chlorides, Bromides, Iodides, and Sulfonates: A General Method for the Preparation of Primary Arylamines.
Vo GD, Hartwig JF.
J Am Chem Soc. 2009 Jul 10. [Epub ahead of print]
PMID: 19591470 [PubMed - as supplied by publisher]
New One-Pot Synthesis of (E)-beta-Aryl Vinyl Halides from Styrenes.
Pawluc´ P, Hreczycho G, Szudkowska J, Kubicki M, Marciniec B.
Org Lett. 2009 Jul 2. [Epub ahead of print]
PMID: 19572730 [PubMed - as supplied by publisher]
The Scope and Limitation of Nickel-Catalyzed Aminocarbonylation of Aryl Bromides from Formamide Derivatives.
Jo Y, Ju J, Choe J, Song KH, Lee S.
J Org Chem. 2009 Jul 2. [Epub ahead of print]
PMID: 19572571 [PubMed - as supplied by publisher]
Electroencephalographic and behavioral convulsant effects of hydrobromide and hydrochloride salts of bupropion in conscious rodents.
Henshall DC, Dürmüller N, White HS, Williams R, Moser P, Dunleavy M, Silverstone PH.
Neuropsychiatr Dis Treat. 2009;5:189-206. Epub 2009 Apr 8.
PMID: 19557114 [PubMed - in process]
A facile route to C2-substituted imidazolium ionic liquids.
Ennis E, Handy ST.
Molecules. 2009 Jun 19;14(6):2235-45.
PMID: 19553895 [PubMed - in process]
Synthesis of 1,3-amino alcohol derivatives via a silicon-mediated ring-opening of substituted piperidines.
McCall WS, Comins DL.
Org Lett. 2009 Jul 2;11(13):2940-2.
PMID: 19552467 [PubMed - indexed for MEDLINE]
Hafnium Bromide is a highly water soluble crystalline Hafnium source for uses compatible with Bromides and lower (acidic) pH. Metallic Bromides are marketed under the trade name AE Bromides™. Most metal bromide compounds are water soluble for uses in water treatment, chemical analysis and in ultra high purity for certain crystal growth applications. Bromide in an aqueous solution can be detected by adding carbon disulfide (CS2) and chlorine. 
Hafnium is a Block D, Group 4, Period 6 element. The number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electronic configuration is [Xe] 4f14 5d2 6s2. In its elemental form hafnium's CAS number is 7440-58-6.The hafnium atom has a radius of 156.4.pm and it's Van der Waals radius is 200.pm. Hafnium is not toxic. Hafnium is one of the Group IV transition elements that is refined from various zirconic mineral deposits. Hafnium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder. It's primary uses are due to its ability as a nuclear "getter" or absorber of neutrons. It is a primary component in nuclear control rods for this purpose. It also finds uses as a dopant in the alloy of 
steel and 
titanium. It is also used in the production of mantles for high intensity incandescent lamps. Hafnium is replacing polysilicon as the principle gate or electrode material in metal oxide semiconductor field effect transistors (MOSFETs) which are the basis for all modern semiconductors. As semiconductors have gotten smaller, the limiting factor in further size reduction has been the ability of the silicon oxide gate to perform below 10 angstroms where leakage occurs. Recent research has been devoted to the development of High-k materials which can function as a di-electric barrier or gate with lower leakage. Using hafnium based alloys as this di-electric gate has allowed for the development of MOSFET gates smaller than 10 angstroms. This allows for further size reduction, reduced switching power requirements and improved performance. Hafnium was first discovered by Dirk Coster in 1923. See Hafnium research below.
