scholarly journals Doubling the Carbonate-Binding Capacity of Nanojars by the Formation of Expanded Nanojars

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3083
Author(s):  
Wisam A. Al Isawi ◽  
Gellert Mezei
Keyword(s):  
Co2 Fixation ◽  
Binding Capacity ◽  
Coordination Complexes ◽  
Anion Binding ◽  
Ionization Mass ◽  
X Ray ◽  
Carbonate Ion ◽  
Carbonate Ions ◽  
Supramolecular Coordination ◽  
Hydration Energies

Anion binding and extraction from solutions is currently a dynamic research topic in the field of supramolecular chemistry. A particularly challenging task is the extraction of anions with large hydration energies, such as the carbonate ion. Carbonate-binding complexes are also receiving increased interest due to their relevance to atmospheric CO2 fixation. Nanojars are a class of self-assembled, supramolecular coordination complexes that have been shown to bind highly hydrophilic anions and to extract even the most hydrophilic ones, including carbonate, from water into aliphatic solvents. Here we present an expanded nanojar that is able to bind two carbonate ions, thus doubling the previously reported carbonate-binding capacity of nanojars. The new nanojar is characterized by detailed single-crystal X-ray crystallographic studies in the solid state and electrospray ionization mass spectrometric (including tandem MS/MS) studies in solution.

scholarly journals Pt(II)-Coordinated Tricomponent Supramolecular Assemblies of Tetrapyridyl Porphyrin and Dicarboxylate Ligands: Are They 2D Bow Ties or 3D Prisms?

2021 ◽  
Author(s):  
Paola Benavides ◽  
Monica A. Gordillo ◽  
Ashok Yadav ◽  
M. Andrey Joaqui-Joaqui ◽  
Sourav Saha
Keyword(s):  
Self Assembly ◽  
Nmr Spectra ◽  
Structural Complexity ◽  
2D Nmr ◽  
Coordination Complexes ◽  
The Self ◽  
Computational Studies ◽  
X Ray ◽  
Supramolecular Coordination ◽  
Bow Tie

Thermodynamically favored heteroleptic coordination of one aza- and another oxo-coordinating ligand with Pt(II) ions yield tricomponent supramolecular coordination complexes (SCCs) that have much greater structural complexity and functional diversity than the traditional bicomponent SCCs containing only one of the ligands. Herein, we demonstrate that heteroleptic coordination of tetrapyridyl porphyrins (M¢TPP, M¢ = Zn or H2) and various dicarboxylate ligands (XDC) having different lengths and rigidity with cis- (Et3P)2PtII corners actually yields bow tie (⋈)-shaped tricomponent [{cis-(Et3P)2Pt}4(M¢TPP)(XDC)2] 4+ complexes featuring a M¢TPP core and two parallel XDC linkers held together by four heteroligated PtII(N,O) corners. Although previous reports have claimed that the self-assembly of these three components produced tetragonal prisms having two cofacial M¢TPP planes connected by four XDC linkers via eight PtII(N,O) corners, our extensive 1 H, 31P, and 2D NMR, ESI-MS, X-ray crystallographic, and computational studies unequivocally demonstrated that in reality, no such prism was formed because instead of connecting two cofacial M¢TPP ligands, the XDC linkers actually bridged two adjacent pyridyl termini of an M¢TPP ligand via shared PtII(N,O) corners, forming bow tie complexes. In addition to direct crystallographic evidence, the NMR spectra of these complexes revealed that the M¢TPP ligands contained two distinct pyrrole protons (4 each)—those located inside the triangles were shielded by and coupled to adjacent XDC linkers, whereas the exposed ones were not—an unmistakable sign of their bow tie structures. Thus, this work not only unveiled novel bow tie-shaped coordination complexes, but also accurately defined the actual structures and compositions of M¢TPP-based tricomponent SCCs.

scholarly journals Pt(II)-Coordinated Tricomponent Self-Assemblies of Tetrapyridyl Porphyrin and Dicarboxylate Ligands: Are They 3D Prisms or 2D Bow Ties?

2021 ◽  
Author(s):  
Paola Benavides ◽  
Monica A. Gordillo ◽  
Ashok Yadav ◽  
M. Andrey Joaqui-Joaqui ◽  
Sourav Saha
Keyword(s):  
Structural Complexity ◽  
2D Nmr ◽  
Coordination Complexes ◽  
Computational Studies ◽  
X Ray ◽  
X Ray Crystallography ◽  
Supramolecular Coordination ◽  
Ct Complex ◽  
A Charge ◽  
Bow Tie

Thermodynamically favored heteroleptic coordination of Pt(II) ions with one aza- and another oxo-coordinating ligand yield tricomponent supramolecular coordination complexes (SCCs), which possess much greater structural complexity and functional diversity than traditional bicomponent SCCs containing only one of the ligands. Through X-ray crystallography, 1H, 31P, and 2D NMR spectroscopies, mass spectrometry, and computational studies, herein, we demonstrated that heteroleptic coordination of tetrapyridyl porphyrins (MTPP, M = Zn or H2) and various dicarboxylate ligands (XDC) having different lengths and rigidity with cis-(Et3P)2PtII corners yielded bow-tie (⋈)-shaped tricomponent [{cis-(Et3P)2Pt}4(MTPP)(XDC)2]4+ complexes featuring a MTPP core and two parallel XDC linkers held together by four heteroligated PtII(N,O) corners and ruled out the MTPP-based tetragonal prism formation. Irrespective of the rigidity and length of the XDC linkers within a certain range (~7–11 Å), they intramolecularly bridged two adjacent pyridyl tips of an MTPP ligand via PtII(N,O) corners, which led to the formation of bow-tie complexes instead of prisms. This happened because the angles of projection between the adjacent pyridyl rings of MTPP cores adapted to accommodate the bridging XDC linkers having different lengths, and the bow-tie formation was entropically favored over tetragonal prisms. This work not only unveiled novel bow-tie-shaped coordination complexes, but also accurately defined the actual structures and compositions of MTPP-based tricomponent SCCs. Furthermore, a representative bow-tie complex containing an electron-rich ZnTPP core selectively formed a charge-transfer (CT) complex with highly electron deficient 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-heaxacarbonitrile (HATHCN) but not with π-donors like pyrene.

scholarly journals A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

2019 ◽  
Vol 15 ◽  
pp. 2767-2773 ◽  
Author(s):  
Constantin Stuckhardt ◽  
Diederik Roke ◽  
Wojciech Danowski ◽  
Edwin Otten ◽  
Sander J Wezenberg ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Molecular Motors ◽  
First Generation ◽  
Substrate Binding ◽  
Coordination Complexes ◽  
Supramolecular Assemblies ◽  
Stimuli Responsive ◽  
X Ray ◽  
Supramolecular Coordination ◽  
Opening Up

In recent years, increasing efforts have been devoted to designing new functional stimuli-responsive supramolecular assemblies. Here, we present three isomeric supramolecular coordination complexes consisting of a Pd2L4 stoichiometry. As shown by NMR, CD and X-ray studies, as well as DFT calculations, these complexes form cage-like structures by chiral self-sorting. Photochromic ligands derived from first generation molecular motors enable light-driven interconversion between the three isomers. Two of the isomers were able to form host–guest complexes opening up new prospects toward stimuli-controlled substrate binding and release.

scholarly journals Pt(II)-Coordinated Tricomponent Supramolecular Assemblies of Tetrapyridyl Porphyrin and Dicarboxylate Ligands: Are They 2D Bow Ties or 3D Prisms?

2021 ◽  
Author(s):  
Paola Benavides ◽  
Monica A. Gordillo ◽  
Ashok Yadav ◽  
M. Andrey Joaqui-Joaqui ◽  
Sourav Saha
Keyword(s):  
Self Assembly ◽  
Nmr Spectra ◽  
Structural Complexity ◽  
2D Nmr ◽  
Coordination Complexes ◽  
The Self ◽  
Computational Studies ◽  
X Ray ◽  
Supramolecular Coordination ◽  
Bow Tie

Thermodynamically favored heteroleptic coordination of one aza- and another oxo-coordinating ligand with Pt(II) ions yield tricomponent supramolecular coordination complexes (SCCs) that have much greater structural complexity and functional diversity than the traditional bicomponent SCCs containing only one of the ligands. Herein, we demonstrate that heteroleptic coordination of tetrapyridyl porphyrins (M¢TPP, M¢ = Zn or H2) and various dicarboxylate ligands (XDC) having different lengths and rigidity with cis- (Et3P)2PtII corners actually yields bow tie (⋈)-shaped tricomponent [{cis-(Et3P)2Pt}4(M¢TPP)(XDC)2] 4+ complexes featuring a M¢TPP core and two parallel XDC linkers held together by four heteroligated PtII(N,O) corners. Although previous reports have claimed that the self-assembly of these three components produced tetragonal prisms having two cofacial M¢TPP planes connected by four XDC linkers via eight PtII(N,O) corners, our extensive 1 H, 31P, and 2D NMR, ESI-MS, X-ray crystallographic, and computational studies unequivocally demonstrated that in reality, no such prism was formed because instead of connecting two cofacial M¢TPP ligands, the XDC linkers actually bridged two adjacent pyridyl termini of an M¢TPP ligand via shared PtII(N,O) corners, forming bow tie complexes. In addition to direct crystallographic evidence, the NMR spectra of these complexes revealed that the M¢TPP ligands contained two distinct pyrrole protons (4 each)—those located inside the triangles were shielded by and coupled to adjacent XDC linkers, whereas the exposed ones were not—an unmistakable sign of their bow tie structures. Thus, this work not only unveiled novel bow tie-shaped coordination complexes, but also accurately defined the actual structures and compositions of M¢TPP-based tricomponent SCCs.

A Molecular Artisans Guide to Supramolecular Coordination Complexes and Metal Organic Frameworks

2015 ◽  
Vol 03 (01n02) ◽  
pp. 1540004 ◽  
Author(s):  
Xialu Wu ◽  
David J. Young ◽  
T. S. Andy Hor
Keyword(s):  
Chemical Reactivity ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Coordination Complexes ◽  
Large Molecules ◽  
Molecular Building Blocks ◽  
Supramolecular Coordination ◽  
Metal Organic ◽  
Molecular Synthesis ◽  
And Function

As molecular synthesis advances, we are beginning to learn control of not only the chemical reactivity (and function) of molecules, but also of their interactions with other molecules. It is this basic idea that has led to the current explosion of supramolecular science and engineering. Parallel to this development, chemists have been actively pursuing the design of very large molecules using basic molecular building blocks. Herein, we review the general development of supramolecular chemistry and particularly of two new branches: supramolecular coordination complexes (SCCs) and metal organic frameworks (MOFs). These two fields are discussed in detail with typical examples to illustrate what is now possible and what challenges lie ahead for tomorrow's molecular artisans.

scholarly journals The fluoride permeation pathway and anion recognition in Fluc family fluoride channels

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Benjamin C McIlwain ◽  
Roja Gundepudi ◽  
B Ben Koff ◽  
Randy B Stockbridge
Keyword(s):  
Binding Sites ◽  
Anion Recognition ◽  
Anion Binding ◽  
Structural Studies ◽  
Planar Bilayer ◽  
X Ray ◽  
X Ray Crystallography ◽  
Molecular Determinants ◽  
Cytoplasmic Accumulation ◽  
Oriented System

Fluc family fluoride channels protect microbes against ambient environmental fluoride by undermining the cytoplasmic accumulation of this toxic halide. These proteins are structurally idiosyncratic, and thus the permeation pathway and mechanism have no analogy in other known ion channels. Although fluoride binding sites were identified in previous structural studies, it was not evident how these ions access aqueous solution, and the molecular determinants of anion recognition and selectivity have not been elucidated. Using x-ray crystallography, planar bilayer electrophysiology and liposome-based assays, we identify additional binding sites along the permeation pathway. We use this information to develop an oriented system for planar lipid bilayer electrophysiology and observe anion block at one of these sites, revealing insights into the mechanism of anion recognition. We propose a permeation mechanism involving alternating occupancy of anion binding sites that are fully assembled only as the substrate approaches.

Coordination Complexes of Tin(IV) Chloride with Unidentate Nitrogen Bases

2004 ◽  
Vol 57 (5) ◽  
pp. 507 ◽  
Author(s):  
Warren A. Grigsby ◽  
Travis S. Morien ◽  
Colin L. Raston ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Single Crystal ◽  
Coordination Complexes ◽  
Toluene Solution ◽  
Neutral Complex ◽  
X Ray ◽  
Nitrogen Bases ◽  
Trigonal Bipyramidal ◽  
Axial Site

A single crystal X-ray study shows the product of reaction between quinuclidine, ‘qn’, and tin(IV) chloride in toluene solution to be, unusually, a five-coordinate neutral complex [qnSnCl4]. Sn—N is 2.282(5) Å in an axial site of a trigonal bipyramidal array, trans to an Sn—Cl bond 2.367(2) with Sn—Cl (equatorial) 2.323(2)–2.333(2) Å. With 1,4-pyrazine, ‘pz’, as adumbrated by earlier spectroscopic work, a 1 : 2 (centro-symmetric) adduct, trans-[pz2SnCl4] is obtained (rather than a pyrazine bridged polymer) [Sn—N 2.246(1), Sn—Cl 2.3883(4), 2.3980(4) Å].

X-Ray Absorption and RIXS on Coordination Complexes

2016 ◽  
pp. 407-435 ◽  
Author(s):  
Thomas Kroll ◽  
Marcus Lundberg ◽  
Edward I. Solomon
Keyword(s):  
Coordination Complexes ◽  
X Ray ◽  
X Ray Absorption
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