Solid state studies of the assembly of diionic guanidinium/carboxylate compounds. Issue 21 (20th May 2015)

• Record Type: Journal Article
• Authors: Wang, Wei; Gu, Jun; Zou, Xiaoliang; Tong, Weiqi; Gong, Hegui
• Is Part Of: Tetrahedron letters. Volume 56:Issue 21(2015)
• Page Start: 2684
• Page End: 2687
• Publication Date: 2015-05-20
• Subjects: Guanidinium -- Carboxylate -- Amino acids -- Ion-pair assisted H-bonding -- Polar solvents; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2015.03.123
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Reported herein are the solid state studies of guanidinium/carboxylate salts or the zwitterionic species derived from amino acids. It was disclosed that carboxylates tend to bond to the two unsubstituted external guanidine (N–H)s, adopting assembly modes A and C depending on the geometry of the linkers. Bonding of carboxylate to the internal (N–H)s was observed only when the external (N–H)s are not available as in5 . This work may be useful for the development of complex linear particularly helical structures and dimeric structures in polar solvents. Abstract: Reported herein are the solid state studies of guanidinium/carboxylate salts or the zwitterionic species derived from amino acids. It was disclosed that carboxylates tend to bond to the two unsubstituted external guanidine (N–H)s, adopting assembly modes A and C depending on the geometry of the linkers. Rigid linkers that inhibit the guanidine and carboxylate planes parallel or on the same plane tend to give helical tapes. Bonding of carboxylate to the internal (N–H)s was observed (mode D) only when the external (N–H)s are not available as in5, suggesting that external bonding modes A and C are possibly energetically more favored than the internal modes B and D. This work may be useful for the development of complex linear particularly helical structures and dimeric structures in polar solvents.