Abstract
Methyl pro-amine {N,N,3-trimethyl-4-[6-(4-methyl-piperazin-1-yl)-1H,3'H-[2,5'-bibenzo[d]imidazol]-2'-yl]aniline}, C28H35N7O2, crystallized as both a dihydrate, C28H31N7·2H2O, and monohydrate, C28H31N7·H2O, form from water in the presence of β-cyclo-dextrin, in the P21/c and P21/n space groups, respectively. The two structures adopt different conformations and tautomeric forms as a result of the differing crystal packing as dictated by hydrogen-bonding inter-actions. The dihydrate crystallizes as a three-dimensional hydrogen-bonded network, while the monohydrate crystallizes as a two-dimensional hydrogen-bonded network.
Highlights
Methyl proamine {N,N,3-trimethyl-4-[6-(4-methylpiperazin-1-yl)-1H,30H-[2,50bibenzo[d]imidazol]-20-yl]aniline}, C28H35N7O2, crystallized as both a dihydrate, C28H31N7Á2H2O, and monohydrate, C28H31N7ÁH2O, form from water in the presence of -cyclodextrin, in the P21/c and P21/n space groups, respectively
In order to examine the conformational and tautomeric differences between the uncomplexed ligand and that which is bound to DNA, the structures of both the dihydrate (1)Á2H2O and the monohydrate (1)ÁH2O, which were grown from water in the presence of -cyclodextrin, are reported
The two structures represent two different conformations of (1); (1)Á2H2O exists in an extended conformation as determined by the C9—C10— C14—N4 torsion angle which is 173.54 (14) with an N1Á Á ÁN6 distance of 17.251 (2) Awhile (1)ÁH2O adopts a crescent shape with a C9—C10—C14—N4 torsion angle of À19.8 (2) and an N1Á Á ÁN6 distance of 16.859 (2) A
Summary
Methylproamine (1) is a bibenzimidazole derivative which binds in the minor groove of DNA in adenine-thymine-rich regions of four or more consecutive AT pairs (Martin et al, 2004) and is related to the Hoechst family of DNA-binding bibenzimidazoles (Pjura et al, 1987). The structure of methylproamine with the DNA dodecamer d(CGCGAATTCGCG) has been determined and reported by us, the structure of the free ligand has not yet been published as it is very difficult to obtain good quality crystals for these types of compounds. In order to examine the conformational and tautomeric differences between the uncomplexed ligand and that which is bound to DNA, the structures of both the dihydrate (1)Á2H2O and the monohydrate (1)ÁH2O, which were grown from water in the presence of -cyclodextrin, are reported.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Acta Crystallographica Section E Crystallographic Communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
