[en] Rotational states in the lightest isotopes of platinum (Z = 78) have been located through the fine structure in α-decay. For ¹⁷⁶Pt the first 2⁺ level is at 263 keV. The favoured α-transitions in the decay of the odd isotopes ^181-185Hg unambiguously identify the bandhead of the 1/2^- [521] Nilsson states in the platinum daughters. In the region N = 98-104 the moments of inertia show a dramatic even-odd staggering amounting to a factor of 2; this behaviour parallels the staggering in < r²> in the mercury (Z = 80) isotopes. (Auth.)