Hydrothermal synthesis and structure of a two-dimensional bimetallic copper–molybdophosphonate, [{Cu4(H2O)2(phenbisterpy)2(HO3P(CH2)4PO3H)}(Mo4FO12)2{O3P(CH2)4PO3}]·4H2O, constructed from {Mo4FO12}1− clusters and copper-ligand chains (phenbisterpy=1,4-bis(2,2′:6′,2′′-terpyridin-4′-yl)benzene)

Synthesis of Cu(II)-Organophosphonate Framework with Predefined Void Spaces

“…As seen in Figure , the square pyramidal {Cu­(terpy)} 2+ is a simple building unit that could coordinate to the organophosphonate ligands via its empty basal and apical coordination sites producing near 90° corners. − In addition to limiting the number of potential phosphonate coordination, fixing the coordination angle to the metal center helps the predictability of the ultimate structure as well. To date, no systematic studies have been reported to test this hypothesis.…”

“…One logical approach to increase the predictability in copper-organophosphonate systems is to engineer the coordination environment of metal centers by using chelating organoimine ligands to limit the number of phosphonate coordination over the copper coordination sphere. The chelating ligands including 2,2′:6′,2″-Terpyridine (terpy), 4′,4⁗-(1,4-Phenylene)­bis­(2,2′:6′,2″-terpyridine) (pbterpy), or 2,2′-bipyridine (2,2′-bpy) regularly produce square pyramidal {Cu­(2,2′-bpy)} 2+ , {Cu­(terpy)} 2+ , and {Cu 2 (pbterpy)} 2+ centers where Cu­(II) has two and three open sites for phosphonate coordination, respectively. − This method has previously been shown to be influential in controlled formation of macrocyclic Cu­(II)-organophosphonate building blocks . Another report using a similar method has used a bridging 4,4′-bipyridine ligand to form isoreticular porous frameworks with the H 2 O 3 PCH 2 -NR-CH 2 PO 3 H 2 type of organophosphonates .…”