Tellurite‐Squarate Driven Assembly of a New Family of Nanoscale Clusters Based on (Mo₂O₂S₂)²⁺

Abstract

The preparation and characterization of a new family of four polyoxothiometalate (POTM) clusters are reported, with varying size and complexity, based upon the dimeric [Mo2O2S2(H2O)6]2+ cation with the general formula (NMe4)aKb[(Mo2O2S2)c(TeO4)d(C4O4)e(OH)f] where a,b,c,d,e,f={1,7,14,2,4,10}=1, {Mo28Te2}; {2,26,36,12,10,48}=2, {Mo72Te12}; {0,11,15,3,3,21}=3, {Mo30Te3}; {2,6,12,2,4,16}=4, {Mo24Te2}. The incorporation of tellurite anions allowed the fine tuning of the templating and bridging of the available building blocks, leading to new topologies of increased complexity. The structural diversity of this family of compounds ranges from the highly symmetrical cross‐shaped {Mo24Te2} to the stacked ring structure of {Mo72Te12}, which is the largest tellurium‐containing POTM cluster reported so far. Also a detailed experimental analysis revealed that the pH isolation window extends from acidic to basic values. ESI‐MS analyses not only confirmed the stability of this family in solution but also revealed the stability of the observed virtual building blocks.

Soluble Hetero‐Polyoxovanadates and Their Solution Chemistry Analyzed by Electrospray Ionization Mass Spectrometry

“…In the field of POM, IM‐MS is frequently used to separate and analyze complex product mixtures after self‐assembly processes . A growing number of examples has been published in which IM‐MS was utilized as a supporting analytical method besides X‐ray crystal structure analysis and NMR spectroscopy to confirm the formation of POMs . Employing IM‐MS even for the major part of the analysis of their POM assemblies, Cronin and co‐workers have published studies on the structural elucidation by IM‐MS in cases, for which no X‐ray crystal structures could be obtained .…”

“…[47] Ag rowingn umber of examples has been published in which IM-MS was utilized as as upporting analytical methodb esides X-ray crystal structure analysisa nd NMR spectroscopy to confirm the formation of POMs. [68] Employing IM-MS even for the major part of the analysiso ft heir POM assemblies, Cronin and co-workersh ave published studies on the structural elucidation by IM-MS in cases, for which no X-ray crystal structures could be obtained. [69] For example, they presented an IM-MS study in which the hierarchical selfassembly of an icosahedraln anoscale Keplerate cluster 9 was shown.…”

Spontaneous formation of a chiral (Mo2O2S2)2+-based cluster driven by dimeric {Te2O6}-based templates

“…This was achieved by the introduction of templates of appropriate size and sufficient rigidity leading to the formation of new building blocks with unsaturated coordination sites which can readily assemble into high nuclearity architectures and give rise to interesting structural features. The combination of the organic squarate (C 4 O 4 2– ) 27 with selenite (SeO 3 2– ) or tellurite (TeO 3 2– ) anions 28 is a representative example of templates that facilitated the generation of new open-ring shaped building blocks leading to an unprecedented number of new compounds with unprecedented structural features 29 – 31 and generation of spontaneous chirality. 30 …”

“…The A and B building blocks are isostructural to the selenium and tellurium templated ones which have been reported by our group previously. 28 , 31 The characteristic bond lengths observed for the two building blocks can be summarized as follows: Te–O bond lengths for A and B vary from 1.887(14)–1.921(9) and 1.831(8)–1.865(7) Å; Mo–Mo bond lengths within the [Mo 2 O 2 S 2 ] 2+ unit are found to be 2.831(1)–2.866(1) and 2.807(1)–2.848(1) Å; Mo–S bond lengths vary from 2.231(3)–2.360(3) and 2.306(3)–2.344(3) Å; and Mo O bond lengths vary from 1.664(8)–1.695(7) and 1.666(9)–1.693(8) Å, respectively. Finally, the Mo–O(Te) distances are found to be 2.142(7)–2.499(8) and 2.198(7)–2.373(7) Å while the distance between the Mo centres and the hydroxo bridges Mo–O(H) spans the ranges 2.056(7)–2.171(7) and 2.100(8)–2.149(8) Å.…”