  In this study, we develop the generalized Dirac like four-momentum equation
for rotating spin-half particles in four-dimensional quaternionic algebra. The
generalized quaternionic Dirac equation consists the rotational energy and
angular momentum of particle and anti-particle. Accordingly, we also discuss
the four vector form of quaternionic relativistic mass, moment of inertia and
rotational energy-momentum in Euclidean space-time. The quaternionic four
angular momentum (i.e. the rotational analogy of four linear momentum) predicts
the dual energy (rest mass energy and pure rotational energy) and dual momentum
(linear like momentum and pure rotational momentum). Further, the solutions of
quaternionic rotational Dirac energy-momentum are obtained by using one, two
and four-component of quaternionic spinor. We also demonstrate the solutions of
quaternionic plane wave equation which gives the rotational frequency and wave
propagation vector of Dirac particles and anti-particles in terms of
quaternionic form.
