Bismuth oxychloride
Encyclopedia
Bismuth oxychloride is a chemical compound
of bismuth
, oxygen
, and chlorine
, with the formula
BiOCl. It exists in nature as the mineral bismoclite which is part of the matlockite
mineral group.
space group
P4/nmm. The crystal structure
can be thought of as consisting of layers of Cl−, Bi3+ and O2− ions, in the order Cl-Bi-O-Bi-Cl-Cl-Bi-O-Bi-Cl.
The bismuth atoms adopt a distorted square antiprism
atic coordination geometry
, with four chlorine atoms forming one of the square faces, each at a distance of 3.06 Å from Bi, and four oxygen atoms forming the other square face, each at a distance of 2.32 Å from Bi.
The oxygen atoms are tetrahedrally coordinated
by four bismuth atoms.
It is formed during the reaction of bismuth chloride
with water.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
of bismuth
Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
, oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
, and chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
, with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
BiOCl. It exists in nature as the mineral bismoclite which is part of the matlockite
Matlockite
Matlockite is a rare lead halide mineral, named after the town of Matlock in Derbyshire, England, where it was first discovered in a nearby mine...
mineral group.
Structure
BiOCl crystallises in the tetragonalTetragonal crystal system
In crystallography, the tetragonal crystal system is one of the 7 lattice point groups. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base and height .There are two tetragonal Bravais...
space group
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
P4/nmm. The crystal structure
Crystal structure
In mineralogy and crystallography, crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a pattern, a set of atoms arranged in a particular way, and a lattice exhibiting long-range order and symmetry...
can be thought of as consisting of layers of Cl−, Bi3+ and O2− ions, in the order Cl-Bi-O-Bi-Cl-Cl-Bi-O-Bi-Cl.
The bismuth atoms adopt a distorted square antiprism
Square antiprism
In geometry, the square antiprism is the second in an infinite set of antiprisms formed by an even-numbered sequence of triangle sides closed by two polygon caps...
atic coordination geometry
Coordination geometry
The term coordination geometry is used in a number of related fields of chemistry and solid state chemistry/physics.-Molecules:The coordination geometry of an atom is the geometrical pattern formed by atoms around the central atom....
, with four chlorine atoms forming one of the square faces, each at a distance of 3.06 Å from Bi, and four oxygen atoms forming the other square face, each at a distance of 2.32 Å from Bi.
| coordination geometry of Bi (side view) |
coordination geometry of Bi (top view) |
The oxygen atoms are tetrahedrally coordinated
Tetrahedral molecular geometry
In a tetrahedral molecular geometry a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1 ≈ 109.5° when all four substituents are the same, as in CH4. This molecular geometry is common throughout the first...
by four bismuth atoms.
Reactions
When BiOCl is heated above 600 °C, it forms Bi24O31Cl10, which can be thought of as Bi24O36 (i.e. Bi2O3) with 5 of the 36 oxygen atoms replaced by chlorine.It is formed during the reaction of bismuth chloride
Bismuth chloride
Bismuth chloride is an inorganic compound with the chemical formula BiCl3. It is a common source of the Bi3+ ion. In the gas phase and in the crystal, the species adopts a pyramidal structure, in accord with VSEPR theory.-Preparation:...
with water.