The Collaborative International Dictionary of English v.0.48:

Impenitence \Im*pen"i*tence\, n. [L. impenitentia: cf. F.
   imp['e]nitence.]
   The condition of being impenitent; failure or refusal to
   repent; hardness of heart.
   [1913 Webster]

         He will advance from one degree of wickedness and
         impenitence to another.                  --Rogers.
   [1913 Webster]

WordNet (r) 3.0 (2006):

impenitence
    n 1: the trait of refusing to repent [syn: impenitence,
         impenitency]

The Devil's Dictionary (1881-1906):

IMPENITENCE, n.  A state of mind intermediate in point of time between
sin and punishment.