Formation of a layered framework structure based upon 4-methyl-2,6-bis(methylphosphonic acid) phenol

Abstract

The trifunctional ligands, [(HO)2P(O)CH2]2C6H2(R)OH, (5-H4)(R = CH3, Br) were prepared in good yield via an Arbusov reaction between P(OEt)3 and the respective 4-R-2,6-bis(chloromethyl)phenols followed by acidic aqueous hydrolysis and they were spectroscopically characterized by IR and NMR techniques. The ligand 5-H4-CH3 readily dissolves lanthanide hydroxide residues and it forms a crystalline complex from aqueous LaCl3 solutions. This complex was characterized by single crystal X-ray diffraction methods and found to adopt a complex 2-D lamellar network in the bc plane. The La(III) inner coordination sphere is seven coordinate formed by oxygen atoms from two water molecules and five phosphonate oxygen atoms from three different ligands. The phenolic oxygen atom is not involved in the ligand binding to La(III).

Novel Luminescent Lanthanide(III) Diphosphonates with Rarely Observed Topology

“…Therefore, the elucidation of the structures of lanthanide phosphonates becomes very important . Up until now, reports on lanthanide phosphonates have still been limited, and a number of them are based on X-ray powder diffraction. − It is considered difficult to obtain single crystals of lanthanide phosphonates suitable for structural studies because of their low solubility and poor crystallinity. These problems can be solved by two methods: (1) introducing polar functional groups into the ligand, such as hydroxy, amino, carboxylate, or crown ether 9-11 and (2) introducing a second ligand such as 5-sulfoisophthalic acid (H 3 BTS) or oxalic acid .…”

Structures and luminescent properties of lanthanide phosphonates

“…13). The hydroxyl group of the ligand remains uncoordinated and is involved in the interlayer hydrogen bonding with lattice water.La(HL 8 )(H 2 O) 2 was prepared by reacting H 4 L 8 and lanthanide chloride in dilute (0.02 M) HCl at 125 • C[44] …”

Synthesis, spectroscopic, and structural characterization of new functionalized gem-bisphosphonate complexes of tin(IV) chloride

“…Such an interest could be explained by the specific properties of bisphosphonate derivatives ranging from pharmacological activities [1][2][3] to their metal-complexing ability [4][5][6][7]. For instance, bisphosphonates have been widely employed in nuclear medicine as ligands for radio-metals in the diagnosis and therapy of several bone diseases, such as osteoporosis and hypercalcemia [8].…”