Name = Plumbane
ImageFile = Plumbane-2D.png
ImageSize = 120
IUPACName = Plumbane
OtherNames = Plumbane, lead tetrahydride, tetrahydridolead, lead(IV) hydride
Section1 = Chembox Identifiers
CASNo = 15875-18-0
Section2 = Chembox Properties
Formula = PbH4
MolarMass = 211.23 g/mol
BoilingPt = -13 °C
Plumbane, PbH4, is a metal
hydridecomprised of leadand hydrogen. [Porritt, C. J. "Chem. Ind-London." 1975, "9", 398] Plumbane is not well-characterized or well-known, and it is thermodynamically unstable with respect to the loss of a hydrogen atom.Hein, T. A.; Thiel, W. "J. Phys. Chem." 1993, "97", 4381] Derivatives of plumbane include lead tetrafluoride, PbF4 and tetra-ethyl lead, (CH3CH2)4Pb.
Until recently, it was uncertain whether plumbane had ever actually been synthesized; [Cotton, F. A.; Wilkinson, G.; Murillo, C. A.; Bochman, M. "Advanced Inorganic Chemistry." Wiley: New York, 1999] although, in 1963, Saalfeld and Svec reported the observation of PbH4+ by mass spectrometry.Saalfeld, F. E.; Svec, H. "Inorg. Chem." 1963, "2", 46.] Plumbane has repeatedly been the subject of Dirac-
Hartree-Fockrelativistic calculation studies, which investigate the stabilities, geometries, and relative energies of hydrides of the formula MH4 or MH2. [Pyykkö, P.; Desclaux, J. P. "Chem. Phys. Lett." 1974, "29", 534] [Pyykkö, P.; Desclaux, J. P. "Nature." 1977, "266", 366]
Plumbane is an unstable colorless
gasand is the heaviest group IV hydride. [ [http://www.hbcpnetbase.com/ CRC Handbook of Chemistry and Physics, Online Edition.] ] Furthermore, plumbane has a tetrahedral (Td) structure with an equilibrium bond distance of 1.73 Å. [Visser, O.; Visscher, L.; Aerts, P. J. C.; Nieuwpoort, W. C. "Theor. Chem. Acc." 1991, "81", 405] By weight percent, the composition of plumbane is 1.91% hydrogen and 98.09% lead. In plumbane, the formal oxidation statesof hydrogen and lead are -1 and +4, respectively. The stability of metal hydrides with the formula MH4 (M = Si-Pb) decreases as the atomic number of M increases.
In general, metal hydrides are formed when hydrogen gas is allowed to react with metals. They can serve to store hydrogen gas, which is highly flammable.
Early studies of PbH4 revealed that the molecule is unstable as compared to its lighter congeners (
silane, germane, and stannane). [Malli, G. L.; Siegert, M.; Turner, D. P. "Int. J. Quantum. Chem." 2004, "99", 940] It cannot be made by methods used to synthesize GeH4 or SnH4.
Recently, plumbane has been synthesized from
lead(II) nitrate, Pb(NO3)2, and sodium borohydride, NaBH4. [Krivtsun, V. M.; Kuritsyn, Y. A.; Snegirev, E. P. "Opt. Spectrosc." 1999, "86", 686] Additionally, a non-nascent mechanism for plumbane synthesis has been developed. [Yan, Z.; et al. "Guangpuxue Yu Guangpu Fenxi." 2005, "25", 1720]
In 2002, Wang, X. et al. carefully studied the preparation of PbH4 by
laser ablationand additionally identified the infrared(IR) bands. [Wang, X.; Andrews, J. "J. Am. Chem. Soc." 2002, "125", 6581]
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