Rutherfordium

Literature References: Rf, Ku, Unq; at. no. 104. Group IVB(4). No stable nuclides. Initial production claimed by two groups. Prepn of isotope 260104 (T½ ~300 msec; spontaneous fission) by 242Pu (22Ne,4n): G. N. Flerov et al., At. Energ. 17, 310 (1964), C.A. 62, 189d (1965); eidem, Phys. Lett. 13, 73 (1964); I. Zvara et al., Radiokhimiya 11, 161, 163 (1969). Prepn of two a-emitting isotopes, 257104 (T½ 4.5 seconds) by 249Cf (12C,4n) and 259104 (T½ 3 seconds) by 249Cf (13C,3n): A. Ghiorso et al., Phys. Rev. Lett. 22, 1317 (1969). Ten isotopes reported; mass numbers 253-262. Longest-lived known isotope, 261104, a-emitter, T½ 65 ±10 seconds, rel. at. mass 261.1089; produced by 248Cm (18O,5n): A. Ghiorso et al., Phys. Lett. B 32, 95 (1970). Chemical properties of isotopes and revised T½ 21 ±1 msec for 260104: L. P. Somerville et al., Phys. Rev. C31, 1801-1815 (1985). Solution chemistry: K. R. Czerwinski et al., Radiochim. Acta 64, 23 (1994); eidem, ibid. 29. Reviews of history, prepn and properties: C. Keller, The Chemistry of the Transuranium Elements (Verlag Chemie, Weinheim, English Ed., 1971) pp 613-618; Silva, "Trans-Curium Elements" in MTP Int. Rev. Sci.: Inorg. Chem., Ser. One vol. 8, A. G. Maddock, Ed. (University Park Press, Baltimore, 1972) pp 71-105; R. J. Silva in The Chemistry of the Actinide Elements vol. 2, J. J. Katz et al., Eds. (Chapman and Hall, New York, 1986) pp 1103-1106; E. K. Hyde et al., Radiochim. Acta 42, 57-102 (1987); Transfermium Working Group, Pure Appl. Chem. 65, 1757-1814 (1993); M. Schädel, Inst. Phys. Conf. Ser. 132, 413-422 (1993). Review of chemistry: D. C. Hoffman, Proc. Robert A. Welch Found. Conf. on Chem. Res., XXXIV, Fifty Years with Transuranium Elements (Houston, Texas, 1990) pp 255-276.