Structures of Bisphosphonate Metal Complexes:  Zinc and Cadmium Complexes of Clodronate and Its Partial Ester Derivatives

Abstract

Four new zinc and cadmium bisphosphonates [{NaZn(Cl2CP2O6H)(H2O)5}]n (1), [{Cd2(Cl2CP2O6)(H2O)4}.H2O]n (2), [{Zn(Cl2CP2O6Pri2)(H2O)3}.H2O]n (3), and [{Cd2(Cl2CP2O6Pri2)2(MeOH)2(H2O)2}.H2O]2 (4) have been prepared and their crystal structures determined by single-crystal X-ray diffractometry. Two bisphosphonate ligands were used: clodronate, (dichloromethylene)bis(phosphonate) and its symmetrical P,P'-diisopropyl ester derivative. The structure of the Zn complex 1 is three-dimensional, consisting of one-dimensional Zn-clodronate chains connected to the three-dimensional network by Na+ ions. The structure of Cd complex 2 consists of double layers, and a unique bond was found between the Cd2+ cation and a Cl atom of clodronate. Zn complex 3 consists of one-dimensional chains, but the binding of the bisphosphonate ligands is unique: in 3 the bisphosphonate ligand is only bidentate. Compound 4 is a tetramer, and hydrogen bonds hold the tetramers together, forming a layered structure.

A new dinuclear platinum complex with a nitrogen-containing geminal bisphosphonate as potential anticancer compound specifically targeted to bone tissues

“…Crystals of HNa1 Á ½(NaCl) were obtained by the sol-gel method which allows an accurate control of the crystallization conditions and the use of small amounts of the starting material [30,31]. Under the acidic conditions required for the preparation of the gel (pH 3.0 obtained by addition of HCl) the compound has protonated pyridine and only one sodium counter-ion.…”

The one-dimensional coordination polymer poly[tetrakis[(4-chlorophenyl)methanaminium] [cadmate-μ-cyclohexaphosphorato]]

“…The Cd atom locates on an inversion centre and is coordinated by six O atoms. The CdO 6 octahedron, sharing six vertex oxygen atoms with two adjacent P 6 O 18 rings, is slightly distorted compared to other cases (Du et al, 2010;Kontturi et al, 2005;Man et al, 2006;Hu et al, 2008). Bond distances Cd-O range from 2.230 (2) to 2.353 (7)Å and angles O-Cd-O range from 83.53 (8) to 88.19 (7) °.…”

“…For the synthesis, see: Schü lke & Kayser (1985). For related structures, see: Du et al (2010); Hu et al (2008); Kontturi et al (2005); Man et al (2006). = 70.100 (3) V = 1102.9 (6) Å 3 Z = 1 Mo K radiation = 1.03 mm À1 T = 293 K 0.22 Â 0.20 Â 0.18 mm…”

Design of a Humidity-Stable Metal–Organic Framework Using a Phosphonate Monoester Ligand

“…A single crystal of [Cu(BDP-i Pr)] ∞ (1) was obtained by the tetramethylorthosilicate gel method. 15 No solvent-accessible voids were formed in 1, nor was the material found to swell to uptake guests (alcohols, alkanes, THF, CHCl 3 , R 4 NCl). Importantly, the CuBDPMe/Et complexes were sensitive to hydrolytic attack, but 1 was stable in boiling water.…”