Tin(II) chloride
General
Systematic name	Tin(II) chloride
Other names	Stannous chloride Tin salt Tin dichloride Tin protochloride
Molecular formula	SnCl2
Molar mass	189.60 g/mol (anhydrous) 225.63 (dihydrate)
Appearance	White crystalline solid
CAS number	[7772-99-8] (anhydrous) [10025-69-1] (dihydrate)
Properties
Density and phase	3.95 g/cm3, anhydrous solid 2.71 g/cm3, dihydrate (15 °C)
Solubility in water	83.9 g/100 ml (0 °C) Hydrolyses in hot water
In ethanol, diethyl ether, acetic acid, acetone, ethyl acetate	soluble
Melting point	246 °C (519 K)
Boiling point	623 °C (896 K)
Structure
Molecular shape	Bent (gas phase)
Coordination geometry	Trigonal pyramidal (anhydrous) Dihydrate also three-coordinate
Crystal structure	Layer structure (chains of SnCl3 groups)
Hazards
MSDS	External MSDS
Main hazards	Corrosive
NFPA 704
R/S statement	R: 22-34-37 S: 26-36/37/39-45
RTECS number	XP8700000 (anhydrous) XP8850000 (dihydrate)
Supplementary data page
Structure & properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	Tin(II) fluoride Tin(II) bromide
Other cations	Tin(IV) chloride Germanium dichloride Lead(II) chloride
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references

Tin(II) chloride (stannous chloride) is a white crystalline solid with the formula SnCl₂. It forms a stable dihydrate, but aqueous solutions tend to undergo hydrolysis, particularly if hot. SnCl₂ is widely used as a reducing agent (in acid solution), and in electrolytic baths for tin-plating. Tin(II) chloride should not be confused with the other chloride of tin, tin(IV) chloride or stannic chloride (SnCl₄). Image File history File links Tin(II) chloride (stannous chloride) Picture taken ca. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... It has been suggested that this article or section be merged with Solution. ... Water has the chemical formula H2O, meaning that one molecule of water is composed of two hydrogen atoms and one oxygen atom. ... Hydrolysis is a chemical process in which a molecule is split into two parts by the addition of a molecule of water. ... Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless chemical compound, one of the alcohols that is most often found in alcoholic beverages. ... Flash point -45 °C Autoignition temperature 170 °C R/S statement R: 12-19-22-66-67 S: 9-16-29-33 RTECS number KI5775000 Supplementary data page Structure and properties n, εr, etc. ... Flash point 43 Â°C R-phrases , S-phrases , , , US Permissible exposure limit (PEL) 10 ppm Supplementary data page Structure & properties n, εr, etc. ... R-phrases , , , S-phrases , , , Flash point -20 °C Autoignition temperature 465 °C RTECS number AL31500000 Supplementary data page Structure & properties n, εr, etc. ... Ethyl acetate, also known as acetic acid ethyl ester, ethyl ethanoate, or acetic ester, is a clear, flammable liquid with a characteristic, not unpleasant smell like certain glues or nail polish removers. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid. ... four sp³ orbitals three sp² orbitals In chemistry, hybridisation is the mixing of atomic orbitals belonging to a same electron shell to form new orbitals suitable for the qualitative description of atomic bonding properties. ... The coordination geometry of an atom is the geometrical pattern formed by its neighbors in a molecule or a crystal. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... A material safety data sheet or MSDS is a form containing data regarding the properties of a particular substance. ... This page provides supplementary chemical data on tin(II) chloride // Thermodynamic properties Spectral data Structure and properties data Material Safety Data Sheet The handling of this chemical may incur notable safety precautions. ... Worker safety and health is the prevention and reduction of the number of occupational safety and health hazards at the places of employment, providing safe and healthful working conditions. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Risk and Safety Statements, also known as R/S statements, R/S numbers, R/S phrases, and R/S sentences, is a system of hazard codes and phrases for labeling dangerous chemicals and compounds. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... This page provides supplementary chemical data on tin(II) chloride // Thermodynamic properties Spectral data Structure and properties data Material Safety Data Sheet The handling of this chemical may incur notable safety precautions. ... This page provides supplementary chemical data on tin(II) chloride // Thermodynamic properties Spectral data Structure and properties data Material Safety Data Sheet The handling of this chemical may incur notable safety precautions. ... The refractive index of a material is the factor by which the phase velocity of electromagnetic radiation is slowed relative to vacuum. ... The dielectric constant εr (represented as or K in some cases) is defined as the ratio: where εs is the static permittivity of the material in question, and ε0 is the vacuum permittivity. ... This page provides supplementary chemical data on tin(II) chloride // Thermodynamic properties Spectral data Structure and properties data Material Safety Data Sheet The handling of this chemical may incur notable safety precautions. ... This page provides supplementary chemical data on tin(II) chloride // Thermodynamic properties Spectral data Structure and properties data Material Safety Data Sheet The handling of this chemical may incur notable safety precautions. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... IR spectrum of a thin film of liquid ethanol. ... Nuclear Magnetic Resonance Spectroscopy is the name given to the technique which exploits the magnetic properties of nuclei. ... Mass spectrometry is an analytical technique to measure the mass-to-charge ratio (m/q) of ions. ... // An ion is an atom or group of atoms with a net electric charge. ... // An ion is an atom or group of atoms with a net electric charge. ... Tin(IV) chloride pentahydrate Tin(IV) chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4. ... Lead(II) chloride Lead(II) chloride is the insoluble salt made by adding sodium chloride to soluble lead(II) compounds such as lead(II) nitrate. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... Quartz crystal A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... Drinking water This article focuses on water as we experience it every day. ... Hydrolysis is a chemical process in which a molecule is split into two parts by the addition of a molecule of water. ... Redox reactions include all chemical processes in which atoms have their oxidation number (oxidation state) changed. ... In chemistry and manufacturing, electrolysis is a method of separating bonded elements and compounds by passing an electric current through them. ... Electroplating is the coating of an electrically conductive item with a layer of metal using electrical current. ... Tin(IV) chloride pentahydrate Tin(IV) chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4. ...

Structure

SnCl₂ has a lone pair, such that the molecule in the gas phase is bent. In the solid state, crystalline SnCl₂ forms chains linked via chloride bridges as shown. The dihydrate is also three-coordinate, with one water coordinated on to the tin, and a second water coordinated to the first. The main part of the molecule stacks into double layers in the crystal lattice, with the "second" water sandwiched between the layers. A lone pair is an electron pair without bonding or sharing with other atoms. ... The chloride ion is formed when the element chlorine picks up one electron to form the anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and are also called chlorides. ... In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ...

Image File history File links Structure of tin(II) chloride (stannous chloride) and related compounds. ...

Chemical properties

Tin(II) chloride can dissolve in less than its own mass of water without apparent decomposition, but as the solution is diluted hydrolysis occurs to form an insoluble basic salt:

Image File history File links Hydrolysis equilibrium for Tin(II) chloride (stannous chloride). ...

Therefore if clear solutions of tin(II) chloride are to be used, hydrochloric acid must be added in order to maintain the equilibrium towards the left-hand side (using Le Chatelier's principle). Solutions of SnCl₂ are also unstable towards oxidation by the air: The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... Look up equilibrium in Wiktionary, the free dictionary. ... In chemistry, Le Chateliers principle can be used to predict the effect of a change in conditions on a chemical equilibrium. ... Redox reactions include all chemical processes in which atoms have their oxidation number (oxidation state) changed. ...

6 SnCl₂(aq) + O₂(g) + 2 Water (molecule)(l) → 2 SnCl₄(aq) + 4 Sn(OH)Cl(Solid|s)

This can be prevented by storing the solution over lumps of tin metal.^[1] Drinking water This article focuses on water as we experience it every day. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... Water has the chemical formula H2O, meaning that one molecule of water is composed of two hydrogen atoms and one oxygen atom. ... A liquid will assume the shape of its container. ... Tin(IV) chloride pentahydrate Tin(IV) chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4. ...

There are many such cases where tin(II) chloride acts as a reducing agent, reducing silver and gold salts to the metal, and iron(III) salts to iron(II), for example: General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ...

SnCl₂(aq) + 2 FeCl₃(aq) → SnCl₄(aq) + 2 FeCl₂(aq)

Solutions of tin(II) chloride can also serve simply as a source of Sn²⁺ ions, which can form other tin(II) compounds via precipitation reactions, for example brown (or black) tin(II) sulfide: Iron(III) chloride, generically called ferric chloride, is an iron-based salt of chemical formula FeCl3. ... Tin(IV) chloride pentahydrate Tin(IV) chloride, also known as tin tetrachloride or stannic chloride is a chemical compound with the formula SnCl4. ... The chemical compound iron(II) chloride, also called ferrous chloride, is an inorganic metal salt. ...

SnCl₂(aq) + Na₂S(aq) → SnS(s) + 2 NaCl(aq)

If alkali is added to a solution of SnCl₂, a white precipitate of hydrated tin(II) oxide forms initially; this then dissolves in excess base to form a stannite salt such as sodium stannite: Sodium sulfide, or Na2S, is a water soluble chemical compound. ... Flash point Non-flammable R/S statement R: none S: none RTECS number VZ4725000 Supplementary data page Structure and properties n, εr, etc. ... For the battery, see alkaline battery The word alkali can mean:- In chemistry, an alkali is a specific type of base, formed as a carbonate, hydroxide or other ionic salt of an alkali metal or alkali earth metal element. ... Tin(II) oxide (stannous oxide) is a chemical material in state of powder, it can help in whiting and this is the main job for it, but since the tin is rejected federally, some are stop using it. ...

SnCl₂(aq) + 2 NaOH(aq) → SnO·H₂O(s) + 2 NaCl(aq)

SnO·H₂O(s) + NaOH(aq) → NaSn(OH)₃(aq)

Anhydrous SnCl₂ can be used to make a variety of interesting tin(II) compounds in non-aqueous solvents. For example, the lithium salt of 4-methyl-2,6-di-tert-butylphenol reacts with SnCl₂ in THF to give the yellow linear two-coordinate compound Sn(OAr)₂ (Ar = aryl).^[2] Flash point non flammable Supplementary data page Structure and properties n, εr, etc. ... Flash point Non-flammable R/S statement R: none S: none RTECS number VZ4725000 Supplementary data page Structure and properties n, εr, etc. ... General Name, Symbol, Number lithium, Li, 3 Chemical series alkali metals Group, Period, Block 1, 2, s Appearance silvery white/gray Atomic mass 6. ... A magnified crystal of salt In chemistry, salt is a term used for ionic compounds composed of positively charged cations and negatively charged anions, so that the product is neutral and without a net charge. ... Flash point 127 °C R/S statement R: 22-36 37 38 S: 26-36 RTECS number GO7875000 Related compounds Related compounds butylated hydroxyanisole Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references BHT is the common... Tetrahydrofuran, also known as THF, hydrofuran, oxolane, oxacyclopentane, or furanidine, is a heterocyclic organic compound. ... In the context of organic molecules, aryl refers to any member of the set of functional groups or substituents that are derived from a simple aromatic ring. ...

Tin(II) chloride also behaves as a Lewis acid, forming complexes with ligands such as chloride ion, for example: In chemistry, a Lewis acid can accept a pair of electrons and form a coordinate covalent bond, after the American chemist Gilbert Lewis. ... A complex in chemistry is a reversible association of molecules, atoms, or ions through weak non-covalent chemical bonds. ... It has been suggested that this article or section be merged with Ligand (biochemistry). ... The chloride ion is formed when the element chlorine picks up one electron to form the anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and are also called chlorides. ...

SnCl₂(aq) + CsCl(aq) → CsSnCl₃(aq)

Most of these complexes are pyramidal, and since complexes such as SnCl₃ have a full octet, there is little tendency to add more than one ligand. The lone pair of electrons in such complexes is available for bonding, however, and therefore the complex itself can act as a Lewis base or ligand. This seen in the ferrocene-related product of the following reaction : Caesium chloride is an ionic compound best known as a structural type. ... This is about the polyhedron. ... The octet rule is a simple chemical theory that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells, similar to the electronic configuration of a noble gas. ... A lone pair is an electron pair without bonding or sharing with other atoms. ... A Lewis base is any molecule or ion that can form a new covalent bond by donating a pair of electrons. ... Ferrocene Fe(C5H5)2 is the prototypical metallocene, a type of organometallic chemical compound, consisting of two cyclopentadienyl rings bound on opposite sides of a central iron atom and forming an organometallic sandwich compound. ...

SnCl₂ + Fe(η⁵-C₅H₅)(CO)₂HgCl → Fe(η⁵-C₅H₅)(CO)₂SnCl₃ + Hg

SnCl₂ can be used to make a variety of such compounds containing metal-metal bonds, for example: General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ...

SnCl₂ + Co₂(CO)₈ → (CO)₄Co-(SnCl₂)-Co(CO)₄

Preparation

Anhydrous SnCl₂ is prepared by the action of dry hydrogen chloride gas on tin metal. The dihydrate is made by a similar reaction, using hydrochloric acid: Hydrogen chloride, also known under the name HCl, is a highly corrosive and toxic colorless gas that forms white fumes on contact with humidity. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ...

Sn(s) + 2 HCl(aq) → SnCl₂(aq) + H₂(g)

The water is then carefully evaporated from the acidic solution to produce crystals of SnCl₂·2H₂O. This dihydrate can be dehydrated to anhydrous using acetic anhydride. General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... Drinking water This article focuses on water as we experience it every day. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... Dehydration is the removal of water (hydor in ancient Greek) from an object. ... Acetic anhydride, also known as acetic acid anhydride, is the condensation product of two molecules of acetic acid. ...

Uses

A solution of tin(II) chloride containing a little hydrochloric acid is used for the tin-plating of steel, in order to make tin cans. An electric potential is applied, and tin metal is formed at the cathode via electrolysis. The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... Electroplating is the coating of an electrically conductive item with a layer of metal using electrical current. ... Three tin cans of varying sizes; the one on front is opened with a pull tab. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... An electrode is a conductor used to make contact with a nonmetallic part of a circuit (e. ... In chemistry and manufacturing, electrolysis is a method of separating bonded elements and compounds by passing an electric current through them. ...

It is used as a catalyst in the production of the plastic polylactic acid (PLA). Polylactic acid or Polylactide (PLA) is a biodegradable, thermoplastic, aliphatic polyester derived from lactic acid. ...

Tin(II) chloride also finds wide use as a reducing agent. This is seen in its use for silvering mirrors, where silver metal is deposited on the glass: Redox reactions include all chemical processes in which atoms have their oxidation number (oxidation state) changed. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...

Sn²⁺(aq) + 2 Ag⁺ → SnCl⁴⁺]](aq) + Ag(s)

A related reduction was traditionally used as an analytical test for Hg²⁺(aq). For example, if SnCl₂ is added dropwise into a solution of mercury(II) chloride, a white precipitate of mercury(I) chloride is first formed; as more SnCl₂ is added this turns black as metallic mercury is formed. General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ... Wiktionary logo Wiktionary[1] is a Wikimedia Foundation project intended to be a free wiki dictionary (including thesaurus and lexicon) in every language. ... Mercury(II) chloride (also called mercuric chloride and corrosive sublimate) is a poisonous white soluble crystalline sublimate of mercury. ... Mercury(I) chloride (chemical formula Hg2Cl2, often still known by its ancient name of calomel) is a chloride of mercury, a heavy, white or yellowish-white substance. ...

In organic chemistry, SnCl₂ is mainly used in the Stephen reduction, whereby a nitrile is reduced (via an imidoyl chloride salt) to an imine which is easily hydrolysed to an aldehyde. The reaction usually works best with aromatic nitriles [[Aryl]-CN. A related reaction (called the Sonn-Müller method) starts with an amide, which is treated with PCl₅ to form the imidoyl chloride salt. Organic chemistry is the scientific study of the structure, properties, composition, reactions, and synthesis of organic compounds that by definition contain carbon. ... A nitrile is any organic compound which has a -CN functional group. ... An imine is a functional group or chemical compound containing a carbon-nitrogen double bond. ... An aldehyde is either a functional group consisting of a terminal carbonyl group or a compound containing a terminal carbonyl group. ... In chemistry, an aromatic molecule is one in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. ... Phosphorus Trichloride Phosphorus Pentachloride Phosphorus trichloride (PCl3) and phosphorus pentachloride (PCl5) are reactive chemicals used as chlorinating reagents in a chemical laboratory. ...

The Stephen reduction is less used today, because it has been mostly superseded by diisobutylaluminium hydride reduction. Image File history File links Download high resolution version (822x450, 15 KB) The Stephen reduction using tin(II) chloride (stannous chloride). ... DIBAH (diisobutylaluminium hydride) is a reducing agent with the formula iBu2AlH, where iBu represents an isobutyl group. ...

Additionally, SnCl₂ is used to selectively reduce aromatic nitro groups to anilines.^[3] In chemistry, an aromatic molecule is one in which electrons are free to cycle around circular arrangements of atoms, which are alternately singly and doubly bonded to one another. ... Nitro may refer to: nitro functional group, a functional group with chemical formula NO2 nitroglycerin, an extremely volatile explosive chemical compound Nitrous, a type of fuel additives for race cars. ... R-phrases , , , , , , S-phrases , , , , , , , Supplementary data page Structure and properties n, εr, etc. ...

SnCl₂ also reduces quinones to hydroquinones. Image File history File links Download high resolution version (1108x349, 4 KB) Summary Description: Reaction scheme of a nitro-group reduction using SnCl2. ... A quinone or benzoquinone is generally defined as an aromatic benzene molecule containing a double ketone functional group. ... R-phrases , , , , , S-phrases , , , Flash point 165 °C RTECS number MX3500000 Supplementary data page Structure and properties n, εr, etc. ...

Stannous chloride is also added as a food additive with E number E512 to some canned and bottled foods, where it serves as a color-retention agent and antioxidant. Food additives are substances added to food to preserve it or improve its flavor and appearance. ... For the mathematical constant see: E (mathematical constant). ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Suppliers/Manufacturers

• Alfa
• Aldrich
• Strem
• Fisher
• VWR

References

1. ^  H. Nechamkin, The Chemistry of the Elements, McGraw-Hill, New York, 1968.
2. ^  B. Cetinkaya, I. Gumrukcu, M. F. Lappert, J. L. Atwood, R. D. Rogers, M. J. Zaworotko, J. Am. Chem. Soc. 102, 2088-2089 (1980).
3. ^  Bellamy, F. D.; Ou, K Tetrahedron Lett. 1984, 25, 839-842.

The Journal of the American Chemical Society (usually abbreviated as , or JACS), is a peer-reviewed scientific journal, published since 1879 by the American Chemical Society. ...

General References

• N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997.
• Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
• The Merck Index, 7th edition, Merck & Co, Rahway, New Jersey, USA, 1960.
• A. F. Wells, 'Structural Inorganic Chemistry, 5th ed., Oxford University Press, Oxford, UK, 1984.
• J. March, Advanced Organic Chemistry, 4th ed., p. 723, Wiley, New York, 1992.