  We report measurement of the ensemble averaged transverse spin relaxation
time (T2*) in bulk and few molecules of the organic semiconductor
tris(8-hydroxyquinolinolato aluminum) or Alq3. This system exhibits two
characteristic T2* times, the longer of which is temperature-independent and
the shorter is temperature-dependent, indicating that the latter is most likely
limited by spin-phonon interaction. Based on the measured data, we infer that
the single particle T2 time is long enough to meet Knill's criterion for fault
tolerant quantum computing, even at room temperature. Alq3 is also an optically
active organic and we propose a simple optical scheme for spin qubit read out.
Moreover, we found that the temperature-dependent T2* time is considerably
shorter in bulk Alq3 powder than in few molecules confined in 1-2 nm sized
cavities, which is suggestive of a new type of ``phonon bottleneck effect''.
This is very intriguing for organic molecules where carriers are always
localized over individual molecules but the phonons are delocalized.
