The study of rhenium hydrides can be traced to the 1950s and included reports of the "rhenide" anion, supposedly Re−. These reports led to a series of investigations by A. P. Ginsberg and coworkers on the products from the reduction of perrhenate.[1]
The rhenide anion, Re−, was based on the product of the reduction of perrhenate salts, such as the reduction of potassium perrhenate (KReO4) by potassium metal.[2] "Potassium rhenide" was shown to exist as a tetrahydrated complex, with the postulated chemical formula KRe·4H2O (potassium rhenide tetrahydrate).[3] This compound exhibits strongly reducing properties, and slowly yields hydrogen gas when dissolved in water. The lithium and thallous salts were also reported. Later research, however, indicates that the "rhenide" ion is actually a hydridorhenate complex. "Potassium rhenide" was shown to be in fact the potassium nonahydridorhenate(VII), K2[ReH9], containing the nonahydridorhenate(VII) anion, [ReH9]2−, in which the oxidation state of rhenium is actually +7.[4][5] Other methods of reduction of perrhenate salts yield compounds containing other hydrido- complexes, including ReH3(OH)3(H2O)−.[6]
Structure, synthesis, and properties
Structure of the [ReH9]2− anion, a tricapped trigonal prism.
Isostructural with [TcH9]2− (nonahydridotechnetate(VII)), [ReH9]2− consists of a trigonal prism with Re atom in the center and six hydrogen atoms at the corners. Three more hydrogen ligands define a triangle lying parallel to the base and crossing the prism in its center (see figure). Although those hydride ligands are not equivalent, their electronic structure is almost the same. The coordination number of 9 in this complex is the highest known for any rhenium complex.
^A. P. Ginsberg; J. M. Miller; J. R. Cavanaugh & B. P. Dailey (1960). "Evidence for the Existence of a Potassium Rhenium Hydride and its Bearing on the Nature of the (−1)-Oxidation State of Rhenium". Nature. 185 (4712): 528–9. Bibcode:1960Natur.185..528G. doi:10.1038/185528a0. S2CID4166868.
^Cobble, J. W. (June 1957). "On the Structure of the Rhenide Ion". The Journal of Physical Chemistry. 61 (6): 727–729. doi:10.1021/j150552a005.
^Floss, J. G.; Grosse, A. V. (1960). "Alkali and alkaline earth rhenohydrides". Journal of Inorganic and Nuclear Chemistry. 16 (1–2): 36–43. doi:10.1016/0022-1902(60)80083-8.
^Kenneth Malcolm Mackay; Rosemary Ann Mackay; W. Henderson (2002). Rosemary Ann Mackay (ed.). Introduction to modern inorganic chemistry (6th ed.). CRC Press. pp. 368–369. ISBN0-7487-6420-8.
^Green, M. L. H.; Jones, D. J. (1965). Emeleus, H.J.; Sharpe, A.G. (eds.). Advances in inorganic chemistry and radiochemistry. Academic Press. pp. 169–172. ISBN0-12-023607-9.
^Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN0-12-352651-5.
^Abrahams, S. C.; Ginsberg, A. P.; Knox, K. (1964). "Transition Metal-Hydrogen Compounds. II. The Crystal and Molecular Structure of Potassium Rhenium Hydride, K2ReH9". Inorg. Chem. 3 (4): 558–567. doi:10.1021/ic50014a026.
^Guggenberger, L. J.; Muetterties, E. L. (1976). "Reaction path analysis. 2. The nine-atom family". J. Am. Chem. Soc. 98 (23): 7221–7225. doi:10.1021/ja00439a019.
^Tao, Y.; Wang, X.; Zou, W.; Luo, G.; Kraka, E. (2022). "Unusual Intramolecular Motion of ReH92– in K2ReH9 Crystal: Circle Dance and Three-Arm Turnstile Mechanisms Revealed by Computational Studies". Inorg. Chem. 61 (2): 1041–1050. doi:10.1021/acs.inorgchem.1c03118. PMID34965110. S2CID245567595.