A hexadecameric copper(II) phosphonate

Abstract

The first example of a hexadecanuclear copper(II) phosphonate containing pyrazole, hydroxide and acetate ancillary ligands has been assembled in a reaction involving copper(II) nitrate, pyrazole, t-butylphosphonic acid and triethylamine.

Coordination Versatility of Pyrazole‐Based Ligands towards High‐Nuclearity Transition‐Metal and Rare‐Earth Clusters

“…[95] The compound has an unusual stability due to the [Fe 4 O 4 ] 4+ core. [100] Chandrasekhar and co-workers have employed the combination of phosphonates and pyrazoles (HL1a, HL1k, HL1l and HL1m) as ligands to form a tetranuclear cadmium(II) compound [101] and copper(II) complexes of different nuclearities, [102][103][104][105] ranging from tetranuclear to hexadecanuclear ( Figure 8). [96] These compounds exhibit similar redox properties, demonstrating that the [Fe 4 O 4 ] 4+ core is redox-active.…”

“…Replacement of the terminal chloride ligands with other ligands and the introduction of the fourth substituent on the pyrazole ring (HL1b and HL1c) were reported. [102][103][104][105] Figure 8. [96] Strong antiferromagnetic interactions between the iron(III) ions are present in the compound [Fe 8 (µ 4 -O) 4 (L1a) 12 Cl 4 ].…”

Molecular enneanuclear CuII phosphates containing planar hexanuclear and trinuclear sub-units: syntheses, structures, and magnetism

“…38,39 Also, pyrazolate ligands are able to form copper metallacycles with diverse nuclearities. [40][41][42] In view of our successful efforts in molecular phosphonate synthesis employing ancillary pyrazole co-ligands, [43][44][45] we were interested in examining the possibility of using a sterically hindered phosphate ligand together with pyrazoles for preparing soluble, molecular, oligonuclear Cu(II) phosphate ensembles. Reported herein are investigations into the synthesis, structural, magnetic and photophysical properties of the first examples of enneanuclear Cu(II) phosphates, [Cu9(Pz)6(μ-OH)3(μ3-OH)(ArOPO3)4(DMF)3] (PzH = pyrazole, Ar = 2,6-(CHPh2)2-4-R-C6H2; R = Me, 2MeAr; Et, 2EtAr; iPr, 2iPrAr; and Ar = 2,6-iPr2C6H3, 2 Dip ).…”

A hexaicosametallic copper(ii) phosphonate

“…18 However, in spite of several efforts we were unable to increase the nuclearity of the Cu(II) phosphonate ensembles beyond sixteen. 19 We now report the synthesis and structural characterization of the hexaicosametallic copper phosphonate [Cu 26 {2,3,5, which is the largest-nuclearity aggregate not only among copper(II) phosphonates, but among all homometallic transition metal phosphonates known so far to the best of our knowledge. Among heteronuclear transition metal phosphonates the largest aggregate is { 20 Efforts to make PXRD correlations between the bulk sample and the crystals for which data have been collected have proved to be difficult.…”