Crystal-Engineered Three-Dimensional Hydrogen-Bonding Networks Built with 1,3,5-Benzenetri(phosphonic acid) and Bipyridine Synthons

Abstract

The phosphonic acid 1,3,5-benzenetri(phosphonic acid) (BTP; 1,3,5-[(OH) 2 PO] 3 -C 6 H 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 motifThe 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-H‚‚‚O-P type hydrogen bonds (2.45-2.48 Å) and one short PO-H‚‚‚OdP hydrogen bond at 2.56 Å 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 Å) to complete the 3D network. The compound with 4,4′-bipyridine is triclinic P1 h, 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.

Extending the Family of Tetrahedral Tectons: Phenyl Embraces in Supramolecular Polymers of Tetraphenylmethane-based Tetraphosphonic Acid Templated by Organic Bases

“…Five protonation constants were found for this compound. 10 The values of the protonation constants are higher than for aromatic diphosphonates 11 but are almost the same as for TPPM. This fact confirms that the higher the presence of phosphonic groups in the acid, the higher the amount of protonation constants.…”

New layered copper 1,3,5-benzenetriphosphonates pillared with N-donor ligands: their synthesis, crystal structures, and adsorption properties

“…[39][40][41][42][43] The use of tri-functional or higher functional organophosphonic acids has been explored to avoid the formation of such conventional dense pillared layered structures and several groups including us have successfully synthesized metal organophosphonates with unique framework structures and properties. [44][45][46][47][48][49][50][51][52] For example, using tri-functional organophosphonic acid 1,3,5-benzenetriphosphonic acid (BTP = H 6 btp), we synthesized a layered zinc phosphonate Zn 2 [C 6 H 3 (PO 3 ) 2 PO 3 H]•0.5H 2 bpy•H 2 O (ZnBP-bpy), which is composed of anionic metal phosphonate layers and protonated 4,4′-bipyridine cations, by a hydrothermal reaction. 49 Interestingly, ZnBP-bpy shows a topotactic transformation to a zeolite-like open-framework with selective cation exchange properties.…”

Effect of electron donating substituents on supramolecular structure of salts having phenylphosphonic acid and pyrazoles

“…The use of phosphonic acid in the construction of 2D or 3D hydrogen bonded supramolecular material and crystal engineering is less developed in comparison to carboxylic acid [12][13][14] and has been limited mainly to metal phosphonates, organic-inorganic hybrid materials, co-crystals and organic salts. Different phosphonic acids have been utilized for the construction of organic salts and co-crystals with a number of organic bases and neutral molecules especially with aniline, ethylenediamine, p-phenylazoaniline, hexamethylenediamine, 2,2 0 -bipyridine, 4,4 0 trimethylene-dipyridine, hexamacrocyclic crown ethers, 4,4 0 -bipyridine, p-dimethylaminopyridine and guanidinium chloride [11,[15][16][17][18][19][20]. In addition, they are widely used for the preparation of metal complexes too [21][22][23][24][25][26][27][28][29][30].…”