Serendipity and Design in the Generation of New Coordination Polymers:  An Extensive Series of Highly Symmetrical Guanidinium-Templated, Carbonate-Based Networks with the Sodalite Topology

Abstract

The serendipitous discovery of a 3D [Cu(CO(3))(2)(2-)](n) network with the topology of the 4(2)6(4) sodalite net in [Cu(6)(CO(3))(12)(CH(6)N(3))(8)].K(4).8H(2)O paved the way for the deliberate engineering of an extensive series of structurally related guanidinium-templated metal carbonates of composition [M(6)(CO(3))(12)(CH(6)N(3))(8)]Na(3-)[N(CH(3))(4)].xH(2)O, where the divalent metal M in the framework may be Mg, Mn, Fe, Co, Ni, Cu, Zn, or Cd. A closely related crystalline material with a [Ca(CO(3))(2)(2-)](n) sodalite-like framework, but containing K(+) rather than Na(+), of composition [Ca(6)(CO(3))(12)(CH(6)N(3))(8)]K(3)[N(CH(3))(4)].3H(2)O was also isolated. All of these compounds were obtained under the simplest possible conditions from aqueous solution at room temperature, and their structures were determined by single-crystal X-ray diffraction. Pairs of guanidinium cations are associated with the hexagonal windows of the sodalite cages, alkali-metal cations are associated with their square windows, and N(CH(3))(4)(+) ions are located at their centers. Structures fall into two classes depending on the metal, M(II), in the framework. One type, the BC type (Im3m), comprising the compounds for which M(2+) = Ca(2+), Mn(2+), Cu(2+), and Cd(2+), has a body-centered cubic unit cell, while the second type, the FC type (Fd3c), for which M(2+) = Mg(2+), Fe(2+), Co(2+), Ni(2+), and Zn(2+), has a face-centered cubic unit cell with edges on the order of twice those of the BC structural type. The metal M in the BC structures has four close carbonate oxygen donors and four other more distant ones, while M in the FC structures has an octahedral environment consisting of two bidentate chelating carbonate ligands and two cis monodentate carbonate ligands.

Coordination polymer networks with s-block metal ions

“…As many gastropods and bivalves use calcium carbonate to build their shells, and/or to form nacre, this mineral has been under investigation for the better understanding of how these animals can construct very robust structures [74]. A guanidinium-templated new carbonate-based network with sodalite topology could thus be realized with magnesium and calcium ions [75]. Among alkaline earth metal carbonates, [Mg 6 (CO 3 ) 12 4 ]·3H 2 O were isolated.…”

“…The calcium ions have four close carbonate oxygen donors and four other more distant ones, while magnesium has an octahedral environment consisting of two bidentate chelating carbonate ligands and two cis monodentate carbonate ligands (Fig. 33) [75].…”

One-dimensional ladder like and two-dimensional polymorphs of heterometallic thiocyanate bridged copper(II) and mercury(II) coordination polymer: Syntheses, structural, vibration, luminescence and EPR studies

“…Examples of both true and pseudo-supramolecular isomers have been reported by various groups [7,[10][11][12][13][14]. Furthermore, with regard to the possible correlation between structure and function [15,16], coordination polymers have became promising and attractive as the materials of the future [17] with specifically tailored, useful properties, such as magnetism [18], electrical conductivity [19], non-linear optical behavior [20], luminescence [21], drug delivery [22], porosity [23] and gas storage [24].…”

Hydrothermal synthesis, crystal structure and luminescence of two new 2D coordination polymers [Ln(IN)(CO3)(H2O)] (LnLa, Eu) constructed by interesting flat lanthanide carbonate layers

“…More recently, in the formation of some larger discrete assemblies [12,13], the carbonates are of great importance as a viable principal anion. Thus, the inclusion of carbonate ions in the polymers will decrease the positive charge and reduce the steric restriction [14,15]. Meanwhile, its highly varied coordination modes and intense affinity toward lanthanide ions will lead to more lanthanide ions being incorporated into the complex.…”

“…For example, the pure lanthanide-based SMMs (single-molecule magnets) utilize ligandmodification in their formation, successfully yielding a range of di- [1], tri- [2], tetra- [3], penta- [4], hexa- [5], octa- [6], decanuclear [7] and wheel lanthanide compounds [8]. Recently, an increasing number of anion-assisted synthesis have been well announced, such as the halide-based Sm 12 [9], Eu 15 [10] clusters and Dy 26 clusters incorporating nitrate [11]. It appears that special anions acting as further modifiers could remarkably improve the lanthanide materials.…”