NMR properties:

Magnetogyric Ratio NMR frequency Natural abundance (NA) Nuclear spin (I) Quadrupole moment (Q) Reference sample
85 Rb 2.5927110^7 rad/sT 9.65494MHz 72.11% 5.5 27.6fm²


85 Rb

(L. rubidus, deepest red) Discovered in 1861 by Bunsen and Kirchoff in the mineral lepidolite by use of
the spectroscope.
The element is much more abundant than was thought several years ago. It is now considered to be the
16th most abundant element in the earth's crust. Rubidium occurs in pollucite, leucite, and zinnwaldite,
which contains traces up to 1%, in the form of the oxide. It is found in lepidolite to the extent of about
1.5%, and is recovered commercially from this source. Potassium minerals, such as those found at
Searles Lake, California, and potassium chloride recovered from the brines in Michigan also contain the
element and are commercial sources. It is also found along with cesium in the extensive deposits of
pollucite at Bernic Lake, Manitoba.
Rubidium can be liquid at room temperature. It is a soft, silvery-white metallic element of the alkali
group and is the second most electropositive and alkaline element. It ignites spontaneously in air and
reacts violently in water, setting fire to the liberated hydrogen. As with other alkali metals, it forms
amalgams with mercury and it alloys with gold, cesium, sodium, and potassium. It colors a flame
yellowish violet. Rubidium metal can be prepared by reducing rubidium chloride with calcium, and by a
number of other methods. It must be kept under a dry mineral oil or in a vacuum or inert atmosphere.
Twenty four isotopes of rubidium are known. Naturally occurring rubidium is made of two isotopes,
85Rb and 87Rb. Rubidium-87 is present to the extent of 27.85% in natural rubidium and is a beta emitter
with a half-life of 4.9 x 1010 years. Ordinary rubidium is sufficiently radioactive to expose a
photographic film in about 30 to 60 days. Rubidium forms four oxides: Rb2O, Rb2O2, Rb2O3, Rb2O4.
Because rubidium can be easily ionized, it has been considered for use in "ion engines" for space
vehicles; however, cesium is somewhat more efficient for this purpose. It is also proposed for use as a
working fluid for vapor turbines and for use in a thermoelectric generator using the
magnetohydrodynamic principle where rubidium ions are formed by heat at high temperature and passed
through a magnetic field. These conduct electricity and act like an amature of a generator thereby
generating an electric current. Rubidium is used as a getter in vacuum tubes and as a photocell
component. It has been used in making special glasses. RbAg4I5 is important, as it has the highest room
conductivity of any known ionic crystal. At 20oC its conductivity is about the same as dilute sulfuric
acid. This suggests use in thin film batteries and other applications.