New, low-energy excitations in Mo107 and Mo109

New ground-state level with spin-parity 1/2(+) is established in Mo-109, 69.8 keV below the previously reported 5/2(+) ground state in this nucleus, based on precise spectroscopy measurements of gamma radiation following spontaneous fission of Cm-248 performed using the Eurogam2 array of anti-Compton spectrometers. Analogous measurement of gamma radiation following spontaneous fission of Cf-252, performed using the Gammasphere array, confirms the new 1/2(+) ground state of Mo-107, proposed recently and establishes the isomeric character of the 5/2(+) first excited state in Mo-107. Two beta-decaying isomers are suggested in Mo-111 nucleus based on regular energy systematics, supporting previous predictions. Low-energy excitations in Mo isotopes are interpreted and compared to calculations reported in the literature. The results suggest shape transition from prolate to oblate deformation at N >= 67.