Rubidium iodide

Rubidium iodide
Names


IUPAC name Rubidium iodide
Identifiers
CAS Number	7790-29-6^Y
3D model (JSmol)	Interactive image
ChemSpider	74226^Y
ECHA InfoCard	100.029.271
PubChem CID	3423208
RTECS number	VL8925000
UNII	18CYW0VL2X^Y
CompTox Dashboard (EPA)	DTXSID00880081
InChI InChI=1S/HI.Rb/h1H;/q;+1/p-1^Y Key: WFUBYPSJBBQSOU-UHFFFAOYSA-M^Y InChI=1/HI.Rb/h1H;/q;+1/p-1 Key: WFUBYPSJBBQSOU-REWHXWOFAR
SMILES [Rb+].[I-]
Properties
Chemical formula	RbI
Molar mass	212.3723 g/mol
Appearance	solid
Density	3.110 g/cm ³
Melting point	646.85 °C (1,196.33 °F; 920.00 K)
Boiling point	1,304 °C (2,379 °F; 1,577 K)
Solubility in water	152 g/100 mL
Magnetic susceptibility (χ)	−72.2·10⁻⁶ cm³/mol
Hazards
Lethal dose or concentration (LD, LC):
LD₅₀ (median dose)	4708 mg/kg (oral, rat)
Safety data sheet (SDS)	External MSDS
Related compounds
Other anions	Rubidium fluoride Rubidium chloride Rubidium bromide Rubidium astatide
Other cations	Lithium iodide Sodium iodide Potassium iodide Caesium iodide Francium iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is ^YN ?) Infobox references

Chemical compound

Rubidium iodide is a salt of rubidium and iodine, with the chemical formula RbI. It is a white solid with a melting point of 642 °C.

Preparation

Rubidium iodide can be synthesized in several ways. One is to use a mixed reaction of rubidium hydroxide and hydriodic acid/hydrogen iodide:^[1]

RbOH + HI → RbI + H₂O

Another method is to neutralize rubidium carbonate with hydriodic acid:^[1]

Rb₂CO₃ + 2HI → 2RbI + H₂O + CO₂

Another method is to use rubidium metal to react directly with iodine, but because rubidium metal is very expensive, it is the least commonly used method. In addition, rubidium reacts violently with halogens and burns:^[1]

2Rb + I₂ → 2RbI

Properties

Rubidium iodide forms colorless crystals, and has a red-violet flame color. The refractive index of the crystals is n_D = 1.6474.^[2] It reacts with halogens to form polyhalides: RbI₃, RbICl₂, RbICl₄.^[3] It is easily soluble in water, liquid ammonia, sulfuric acid, RbI·6NH₃ and RbI·3SO₂. Rubidium iodide is soluble only in the following solvents:

Solubility of RbI in organic solvents^[4]
(given in g RbI in 100 cm³ saturated solution)
Solvent	0 °C	25 °C
Acetonitrile	1.478	1.350
Propionitrile	0.274	0.305
Nitromethane	0.567	0.518
Acetone	0.960	0.674
Furfural		4,930

The standard enthalpy of formation of rubidium iodide is Δ_fH⁰₂₉₈ = −328.7 kJ mol⁻¹,^[5] the standard free enthalpy of formation ΔG⁰₂₉₈ = −325.7 kJ mol⁻¹,^[5] and the standard molar entropy S⁰₂₉₈ = 118.11 J K⁻¹·mol⁻¹.^[5]

Rubidium iodide has a sodium chloride structure; its lattice constant is a = 7.326 Å, and the Rb–I bond length is 3.66 Å.^[3]

Applications

Rubidium iodide is used as a component of eye drops, in which it is sold in Romania under the name Rubjovit^® (containing 8 mg/ml RbI).^[6] Another product is Polijodurato^®. However, there are studies that show that rubidium iodide has allergy-triggering^[7] and inflammation-causing^[8] side effects. Homeopathic products containing rubidium iodide are available under the name 'Rubidium iodatum'. In the past, towards the end of the 19th century, it was used to treat syphilis.^[9]

It found isolated use in organic synthesis, for example for the targeted saponification of a polymethylated phosphate.^[10]

References

^ ^a ^b ^c "WebElements". Archived from the original on 2008-04-18. Retrieved 23 February 2006.
^ Ans, Jan d'; Ans, Jan d' (1998). Elemente, anorganische Verbindungen und Materialien. Taschenbuch für Chemiker und Physiker / D'Ans (4., neubearb. u. rev. Aufl ed.). Location not known: Publisher not known. ISBN 978-3-540-60035-0.
^ ^a ^b 『化学大辞典』　共立出版、1993年
^ Aterton Seidell (1940). Solubilities Of Organic Compounds Vol - I. Carnegie-Mellon University Hunt Library, N.Sathyanarayanan. D.Van Nostrand Co.
^ ^a ^b ^c Dickerson, Richard E.; Sichting, Hans-Werner, eds. (1988). Prinzipien der Chemie (2., bearb. und erw. Aufl ed.). Berlin: de Gruyter. ISBN 978-3-11-009969-0.
^ Jurja, Sanda, et al. "Correlation between effectiveness and antioxidant activity of some anti cataract eye drops." Rev Chim (Bucharest) 67 (2016): 1004-1007.
^ "Allergen Rubidium Allergie enthalten Allergologie". www.alles-zur-allergologie.de. Retrieved 2023-09-16.
^ Cameli, N.; Bardazzi, F.; Morelli, R.; Tosti, A. (Nov 1990). "Contact dermatitis from rubidium iodide in eyedrops". Contact Dermatitis. 23 (5): 377–378. doi:10.1111/j.1600-0536.1990.tb05182.x.
^ Paschalis, C.; Jenner, F. A.; Lee, C. R. (May 1978). "Effects of rubidium chloride on the course of manic-depressive illness". Journal of the Royal Society of Medicine. 71 (5): 343–352. doi:10.1177/014107687807100507. ISSN 0141-0768. PMC 1436619. PMID 349155.
^ Turhanen, Petri A. (2014-07-03). "Synthesis of Triple-Bond-Containing 1-Hydroxy-1,1-bisphosphonic Acid Derivatives To Be Used as Precursors in "Click" Chemistry: Two Examples". The Journal of Organic Chemistry. 79 (13): 6330–6335. doi:10.1021/jo500831r. ISSN 0022-3263.