Hang on ... Steve is getting his scientific heroines mixed up. Jocelyn Bell (now Bell-Burnell) discovered pulsars and certainly didn't get the credit she deserved in the form of a Nobel prize, though whether that was sexism or just a case of a supervisor taking credit is debatable. The woman who did the x-ray crystallography on DNA was Rosalind Franklin, and the main reason she didn't get the Nobel prize was that she had died, and Nobel prizes are not (supposed to be) given out posthumously. If she had survived then it would have made an interesting dilemma since Nobel prizes can be given to a maximum of 3 recipients*, so which of the three who actually got it, Crick, Watson or Wilkins, shuld have been booted out to make way for her?
[*so how an organisation like the IPCC can get a Nobel, never mind a charlatan like Fred Singer claim he is a Nobel laureate because he worked for IPCC as a token skeptic/denier, beats me...]
Two-dimensional molecules: Graphene for one. And I think organic molecules where every carbon has no more that 3 other atoms joined to it can also be flat, e.g. benzene.