Unexpected Dimerization of a N₅O₃ Cryptand in Aqueous Solution after Being Protonated by Hydrochloric Acid

Abstract

An unexpected dimerization of a cryptand L with N₅O₃ donors, C₃₃H₄₅N₅O₃, was observed in aqueous solution when L was treated by hydrochloric acid in MeOH and washed with EtOH. The crystal dimerization product is a complex (H₂L²)²⁺·2Cl^-·5HCl·18H₂O (1) (where the neutral dimeric cryptand L² is C₆₆H₉₀N₁₀O₆). The crystal complex L²·2HCl ·3H₂O (2) was ­obtained when complex 1 was neutralized with aqueous solution of NaOH. The two complexes have been characterized by X-ray diffraction, NMR and MS. The conformation of L² in 1 is endo-endo-endo-endo, and the two nitrogen atoms of four bridgehead tertiary nitrogen atoms of L² are protonated. However, conformation of L² in 2 is endo-exo-endo-exo, and the L² is neutral.

Key words

dimerization - host-guest chemistry - cryptand - crystal structure

References

• 1 Arduini A. Ferdani R. Pochini A. Secchi A. Ugozzoli F. Angew. Chem. Int. Ed.  2000,  39:  3453 
• 2 Colby DA. Lash TD. J. Org. Chem.  2002,  67:  1031 
• 3 Ma BQ. Coppens P. Chem. Commun.  2003,  412 
• 4 You J.-S. Yu X.-Q. Xie R.-G. Zhang G.-L. Xiang Q.-X. Lang J.-B. Xie R.-G. Chem. Commun.  2001,  1816 
• 5 Szumna A. Jurczak J. Eur. J. Org. Chem.  2001,  4031 
• 6 Rekharsky M. Yamamura H. Kawai M. Inoue Y. J. Am. Chem. Soc.  2001,  123:  5360 
• 7 Liu Y. Li B. You C.-C. Wada T. Inoue Y. J. Org. Chem.  2001,  66:  225 
• 8 Kim SY. Jung IS. Lee E. Kim J. Sakamoto S. Yamaguchi K. Kim K. Angew. Chem. Int. Ed.  2001,  40:  2119 
• 9 Kim J. Jung IS. Kim SY. Lee E. J. Am. Chem. Soc.  2000,  122:  540 
• 10 Borovkov VV. Lintuluoto JM. Inoue Y. J. Am. Chem. Soc.  2001,  123:  2979 
• 11 Kurtan T. Nesnas N. Li YQ. J. Am. Chem. Soc.  2001,  122:  5962 
• 12a Fabbrizzi L. Leone A. Taglietti A. Angew. Chem. Int. Ed.  2001,  40:  3066 
• 12b Zhang XX. Izatt RM. Bradshaw JS. Krakowiak KE. Coord. Chem. Rev.  1998,  174:  179 
• 12c Jasat A. Sherman JC. Chem. Rev.  1999,  99:  931 
• 13a Fox OD. Rolls TD. Drew MGB. Beer PD. Chem. Commun.  2001,  1632 
• 13b Lehn J.-M. Acc. Chem. Res.  1978,  11:  49 
• 14a Das G. Tripathi P. Tripathi A. Bharadwaj PK. Tetrahedron  2000,  56:  1501 
• 14b Sarkar B. Mukhopadhyay P. Bharadwaj PK. Coord. Chem. Rev.  2003,  236:  1 
• 15a Hardie MJ. Malic N. Raston CL. Roberts BA. Chem. Commun.  2001,  865 
• 15b Pierre J.-L. Chautemps P. Refaif SM. Beguin CG. Marzouki AF. Serratrice G. Rey P. Laugier J. J. Chem. Soc., Chem. Commun.  1994,  1117 
• 15c Thompson JA. Barr ME. Ford DK. Silks LA. McCormick J. Smith PB. Inorg. Chem.  1996,  35:  2025 
• 16a Arnaud-Neu F. Fuangswasdi S. Maubert B. Nelson J. MeKee V. Inorg. Chem.  2000,  39:  573 
• 16b Brooker S. Ewing JD. Nelson J. Inorg. Chim. Acta  2001,  317:  53 
• 17 Chand DK. Bharadwaj PK. Inorg. Chem.  1998,  37:  5050 
• 19a

  The free cryptand L was prepared in ethanol by the procedure we formerly reported.

• 19b Ma Z. Yang RD. Yan L. Chin. Chem. Lett.  1999,  10:  995 
• 20 Sheldrick GM. SHELXL, Program for Crystal Structure Refinement   University of Göttingen; Germany: 1993. 

18

Ma, Z.; Liu, S.-X.; Yang, R.-D. to be submitted.