12027-05-3

Basic information

• Product Name: hafnium tetrahydrate
• CAS NO: 12027-05-3
• Molecular Formula: H₄HfO₄
• Molecular Weight: 250.5511
• Mol File: 12027-05-3.mol
• Article Data: 3

Chemical Properties

• Boiling Point: 100°C at 760 mmHg
• Vapor Pressure: 24.5mmHg at 25°C
• CAS DataBase Reference: hafnium tetrahydrate(CAS DataBase Reference)
• NIST Chemistry Reference: hafnium tetrahydrate(12027-05-3)
• EPA Substance Registry System: hafnium tetrahydrate(12027-05-3)

Safety Data

• Hazardous Substances Data: 12027-05-3(Hazardous Substances Data)

Usage

General Description

Hafnium tetrahydrate is a chemical compound that consists of hafnium ions complexed with four molecules of water. It is commonly used in the production of high-quality hafnium oxide films, which have applications in microelectronics, particularly in the development of advanced capacitors and transistors. Hafnium tetrahydrate is also used in the preparation of other hafnium compounds and in the purification processes of hafnium metal production. It is known for its high water solubility and stability, making it a versatile and important compound in the field of materials science and technology.

Upstream product

• 7732-18-5 water 
• 13499-05-3 hafnium tetrachloride 
• 1333-74-0 hydrogen 
• 80937-33-3 oxygen 
• 124-43-6 urea hydrogen peroxide adduct 
• 13777-22-5 hafnium tetrabromide 

Downstream Products

• 15461-28-6 hafnium(IV) dichloride oxide octahydrate 

Relevant articles and documents

Infrared spectrum and structure of the Hf(OH)4 molecule

Laser-ablated Hf atoms react with H2O2 and with H2 + O2 mixtures in solid argon to form the Hf(OH) 2 and Hf(OH)4 molecules, which are identified from the effect of isotopic substitution on the matrix infrared spectra. Electronic structure calculations at the MP2 level varying all bond lengths and angles converge to nearly linear and tetrahedral molecules, respectively, and predict frequencies for these new product molecules and mixed isotopic substituted molecules of lower symmetry that are in excellent agreement with observed values, which confirms the identification of these hafnium hydroxide molecules. This work provides the first evidence for a metal tetrahydroxide molecule and shows that the metal atom reaction with H2O2 in excess argon can be used to form pure metal tetrahydroxide molecules, which are not stable in the solid state.

Thermodynamic Properties of Zirconium and Hafnium Hydroxides in Aqueous Solution

The enthalpies of solution of ZrCl4, ZrBr4, HfCl4, and HfBr4 in water and low-acidity and low-basicity solutions at 25°C are measured with an isothermal-jacket calorimeter. The standard enthalpies of formation of Zr(OH)4 and Hf(OH)4 in solution and the thermodynamic characteristics of formation of zirconium and hafnium tetrahydroxo complexes in aqueous solution are calculated.