20845-48-1Relevant academic research and scientific papers
Synthetic Considerations in the Self-Assembly of Coordination Polymers of Pyridine-Functionalized Hybrid Mn-Anderson Polyoxometalates
Yazigi, Fran?ois-Joseph,Wilson, Claire,Long, De-Liang,Forgan, Ross S.
, p. 4739 - 4748 (2017)
The incorporation of polyoxometalates (POMs) as structural units into ordered porous constructs such as metal-organic frameworks (MOFs) is desirable for a range of applications where intrinsic properties inherited from both the MOF and POM are utilized, including catalysis and magnetic data storage. The controlled self-assembly of targeted MOF topologies containing POM units is hampered by the wide range of oxo and hydroxo units on the peripheries of POMs that can act as coordinating groups toward linking metal cations leading to a diverse range of structures, but incorporation of organic donor units into hybrid POMs offers an alternative methodology to programmably synthesize POM/MOF conjugates. Herein, we report six coordination polymers obtained serendipitously wherein Zn2+ and Cu2+ link pyridine-appended Mn-Anderson clusters into two- and three-dimensional network solids with complex connectivities and topologies. Careful inspection of their solid-state structures has allowed us to identify common structure-directing features across these coordination polymers, including a square motif where two Zn2+ cations bridge two POMs. By correlating certain structural motifs with synthetic conditions, we have formulated a series of design considerations for the self-assembly of coordination polymers of hybrid POMs, encompassing the selection of reaction conditions, coligands, and linking metal cations. We anticipate that these synthetic guidelines will inform the future assembly of hybrid POMs into functional MOF materials.
A Chemically Soldered Polyoxometalate Single-Molecule Transistor
Cai, Chenxin,Higgins, Simon J.,Nichols, Richard J.,Qiao, Xiaohang,Robertson, Craig M.,Vezzoli, Andrea,Wu, Chuanli
, p. 12029 - 12034 (2020)
Polyoxometalates have been proposed in the literature as nanoelectronic components, where they could offer key advantages with their structural versatility and rich electrochemistry. Apart from a few studies on their ensemble behaviour (as monolayers or thin films), this potential remains largely unexplored. We synthesised a pyridyl-capped Anderson–Evans polyoxometalate and used it to fabricate single-molecule junctions, using the organic termini to chemically “solder” a single cluster to two nanoelectrodes. Operating the device in an electrochemical environment allowed us to probe charge transport through different oxidation states of the polyoxometalate, and we report here an efficient three-state transistor behaviour. Conductance data fits a quantum tunnelling mechanism with different charge-transport probabilities through different charge states. Our results show the promise of polyoxometalates in nanoelectronics and give an insight on their single-entity electrochemical behaviour.
{P2V3W15}-Polyoxometalates Functionalized with Phthalocyaninato y and Yb Moieties
Pütt, Ricarda,Koz?owski, Piotr,Werner, Irina,Griebel, Jan,Schmitz, Sebastian,Warneke, Jonas,Monakhov, Kirill Yu.
, p. 80 - 86 (2021)
A tris(alkoxo)pyridine-augmented Wells-Dawson polyoxometalate (nBu4N)6[WD-Py] (WD = P2V3W15O59(OCH2)3C, Py = C5H4N) was functionalized with phthalocyaninato metal moieties (MPc where M = Y or Yb and Pc = C32H16N8) to afford (nBu4N)4[HWD-Py(MPc)] compounds. High-resolution mass spectrometry was used to detect and identify the hybrid assembly. The magnetism studies reveal substantial differences between M = Yb (monomeric, single-ion paramagnetism) and M = Y (containing dimers, radical character). The results of electronic paramagnetic resonance spectroscopy, SQUID magnetometry, and magnetochemical calculations indicate the presence of intramolecular charge transfer from the MPc moiety to the polyoxometalate and of intermolecular charge transfer from the MPc moiety of one molecule to the polyoxometalate unit of another molecule. These compounds with identified VIV ions represent unique examples of transition-metal/lanthanide complex-POM hybrid compounds with nonphotoinduced charge transfer between electron donor and acceptor centers.
Thermodynamics of host-guest interactions between methylpyridinium salts and phosphonate cavitands
Menozzi, Daniela,Biavardi, Elisa,Massera, Chiara,Schmidtchen, Franz-Peter,Cornia, Andrea,Dalcanale, Enrico
, p. 768 - 775 (2010)
In this work, the properties of complexation of tetraphosphonate cavitands towards methylpyridinium guests were investigated via isothermal titration calorimetry (ITC). For this purpose, Tiiii[C3H7, CH 3, Ph], Tiiii[C
