Crystal-engineered three-dimensional hydrogen-bonding networks built with 1,3,5-benzenetri(phosphonic acid) and bipyridine synthons Academic Article uri icon


  • The phosphonic acid 1,3,5-benzenetri(phosphonic acid) (BTP; 1,3,5-[(OH) 2PO] 3-C 6H 3) can act as both a hydrogen bond donor and acceptor. BTP was reacted with two organic bases, 2,2-bipyridine and 4,4-bipyridine, in a 1:1 molar ratio. The bis-deprotonation and tris-deprotonation trigger the formation of self-complementary 3D hydrogen bonding architectures. Layers of the 2,2-bipyridine compound are formed through hydrogen bonding of the phosphonic acid groups existing in the dianionic motif {1,3-[(OH)PO 2] 2-5-[PO(OH) 2]-C 6H 3} 2-. The ratio of BTP to 2,2-bipyridine is 1:1.5, with two of the phosphonic acid protons being transferred to the nitrogen atoms, leaving a negatively charged oxygen and a proton on each of the phosphonic acid groups. Discrete dimers are formed by three very short PO-HO-P type hydrogen bonds (2.45-2.48 A) and one short PO-HO=P hydrogen bond at 2.56 interconnecting all dimers into extended layers in the bc plane. The protonated bipyridyls penetrated into the layers by formation of two NH +O-P hydrogen bonds (2.72, 3.14 A) to complete the 3D network. The compound with 4,4-bipyridine is triclinic P1, in which the ratio of BTP to bipyridine is 1:1. Each amino nitrogen atom is protonated, leaving each phosphonic acid group negatively charged. One additional positive charge is provided by a hydronium ion. The BTP molecules align in hydrogen-bonded staircase chains along the b axis, in which the molecules are bonded together by double hydrogen bonds: P-O -HO-P. The staircases are then interwoven into each other by the NH +O-P hydrogen bonds between the pyridyl and the phosphonic acid groups. 2005 American Chemical Society.

published proceedings


author list (cited authors)

  • Kong, D. Y., Clearfield, A., & Zon, J.

citation count

  • 51

complete list of authors

  • Kong, Deyuan||Clearfield, Abraham||Zoń, Jerzy

publication date

  • August 2005