A survey of the behavior of the hydroxybisphosphonic function in crystallized acids, metallic salts, and some related compounds

Abstract

FIGURE 1The molecule of hydroxyethylidenebisphosphonic acid with the chosen standardization for the atom names. (In the case of other compounds the hydrogen atoms eventually linked to O1 and O6 are named respectively H1 and H6). ABSTRACT:

Contribution of Neutron Diffraction to the Crystal Structure Determination of 1-Hydroxy-1-Phosphono-Pentyl-Phosphonic Acid Dimethyl Ammonium Salt

“…The bond distances C-OH, P ¼ O, P-O À and P-OH as well as the P-C-P angle agree well with the average of the analogous of bisphosphonated acids and their complex salts (5). The relative displacement between the two ÀPO 3 groups, measured by the pseudo-torsion angles (O11-P1/P2-O21 (39.9(2)), O13-P1/P2-O22 (35.4(1)) and O12-P1/P2-O23(52.6(1)), indicates that in the crystals of p-HBPA the hydroxybisphosphonate group presents a staggered configuration.…”

“…Several crystalline structures of these biologically active acids and of their complex salts are known and have been compared in (5). The structures of uncomplexed acids with an extended alkyl amino chain linked to the carbon central atom are zwitterionic species like amino acids.…”

“…To solve some ambiguities arising from H-positions obtained from X-ray diffraction, these interesting hydrogen bond systems must be determined with precision by neutron diffraction. Only two structures of the HBPA family were solved by this technique (5).…”

The analysis of pH‐dependent protonated conformers of 1‐hydroxyethylidene‐1,1‐diphosphonic acid by means of FT‐Raman spectroscopy, multivariate curve resolution and DFT modelling

“…[6] HEDP has a very high affinity for metal ions, as can be evidenced from the number of solid-state structures of complexes that have been reported. [7] Some of these complexes are highly insoluble and immediately precipitate upon formation, making the study of complexes formed in solution by commonly employed techniques difficult. HEDP itself is a strong acid, as a 0.5 M solution has a pH of 0.98, and can therefore upon addition to an aqueous system, drastically affect the pH of that system.…”

Racemic trans-1,2-diaminocyclohexane as a template in the synthesis of ligands for transition metal and actinide in vivo detoxification

“…Phosphonic derivatives, and the more elaborated hydroxy bis phosphonic acids are widely used as complexing agents for calcium, zinc 2,3 and/or a number of bivalent metals, they are involved in a large number of biochemical processes and diseases treatments 4,5 or diagnostics (scintigraphy in the case of 99m Tc). The aim of this report is to build polyphosphonic compounds grafted to a poly amino tetra-substituted template and to analyze their properties including acidity, stability, kidney clearance, all associated with a mandatory low level toxicity.…”