This disclosure provides double-stranded RNA complexes having one or more hydroxymethyl substituted nucleomonomer(s) in the passenger strand (or sense strand) of an RNA complex. RNA complexes of the disclosure may be useful for therapeutic applications, diagnostic applications or research applications. RNA complexes include short interfering RNA complexes (siRNA) capable of modulating gene expression comprising an antisense strand and a continuous or a discontinuous passenger strand (&ldquo；sense strand&rdquo；). Further, one or more hydroxymethyl substituted nucleomonomer(s) of this disclosure may be positioned at the 3&prime；-end, at the 5&prime；-end, at both the 3&prime；-end and 5&prime；end.
