In this paper, we investigate a new structure of unit speed associated
curves, such as spatial quaternionic and quaternionic osculating
direction curves. For this, we assume that the vector fields 휒.%/ =
휐1.%/t.%/+ 휐2.%/n.%/+ 휐3.%/b.%/ where 휐2 1.%/+ 휐2 2.%/ = 1
for the spatial quaternionic curve and 휒.%/ = 휆1.%/æ.%/ +
휆2.%/휂.%/ + 휆3훽2.%/, where 휆2 1.%/+휆2 2.%/+휆2 3.%/ = 1 for
the quaternionic curve 휙. Then, we give the relationship between
(spatial) quaternionic (OD)-curves and Mannheim curve pair. Moreover, we
examine in which cases the (spatial) quaternionic (OD)-curve can be
helix or slant helix. Finally, we give the examples and draw the figures
of curves in the examples.